text:
Do wallet stealing viruses exist?
After I install the bitcoin client, what are the risks of browsing the Internet? Can my wallet be stolen?
Are there any known viruses/websites etc....?

Money can now be stored in a single file inside your hard drive. This is a natural target for criminals so yes, there are virus that steal bitcoins.
If you trust a third party (like an ewallet) to hold your coins, you will not have to worry about wallet stealing virus nor about wallet security. Instead, you should protect your login credentials and/or use a two-factor authentication mechanism. Treat your e-wallet account the same way you treat your e-banking account.
I don't know of any dangerous websites, but there was a report of a bitcoin trojan by Symantec on June 2011.

Honestly I'm not sure I would trust an ewallet except for one in a major exchange like mtgox or tradehill, and even then, as was shown a short while ago, they are not truly secure either, and just make a more juicy target.

Yes they do exist, your best bet is to create a secure wallet
.  That link goes to another question about how to create a secure wallet.

Since there are circumstances under which it's unreasonable to use secure wallets, it's also good to follow standard security practices with regards to antivirus, firewall, etc. I recommend any virus scanner with the ability to sandbox unknown applications (such as Comodo), effectively isolating them from your wallet.

I personally keep 3 wallets, a 'savings' wallet, which is very secure, only stored on encrypted media, off my computer. A public facing wallet, which keeps my primary spending cash and recieving accounts, and then a pocket change wallet that is on my android phone.. admittedly I've only used it once, but maybe someday!

Yes, and they are more dangerous than they first appear
Consider the situation that a wallet stealing tojan infiltrates your computer/smartphone. All it has to do is make a copy of your wallet.dat file (or equivalent) and send that copy back to base. It can then safely delete itself since it has completed it's mission.
Now comes the dangerous part.
Over the course of time confidence in Bitcoin grows and you make the fatal error of not securing your wallet and start to keep larger and larger sums of Bitcoins in it. Years may pass. Eventually, the person who now has a duplicate of your wallet (a black market in trading these duplicates may arise) may decide to cash out. All you see is that a very large anonymous transfer suddenly occurs out of your wallet and into theirs. You'll be completely powerless to prevent or recover these losses.
So, make a secure wallet.

This does not answer the question.

Also you're missing the fact that the coppied wallet will only contain addresses created at the time of theft. 100 addresses down the road, and that coppied wallet might well be useless.


text:
What are the minimum security expectations of an online wallet service?
If you wanted to assess the security of an online wallet service such as a bitcoin bank or ewallet, what would expect to see addressed?
Obviously SSL connections, but what about authentication, authorization, protection of staff from rubber hose attacks and so on?

It would be impractical to list every single expectation here, but the TradeHill exchange sets themselves up for PCI compliance. I think being PCI compliant is a great set of standards to keep your data safe and secure.
PCI compliance is basically security standards setup by the PCI Security Standards Concil for merchants who accept credit cards, online or offline. They have 4 sets of levels of PCI compliance, which I believe TradeHill to abide to the first level (at the bottom).
Common sense comes into play when storing Bitcoins. Keep a small percentage of them online for immediate usage, when your hot storage gets empty, fill it back up with funds stored offline. Keep multiple secure backups of your wallet files, so a 'bitomat' doesn't happen.
I don't think there is anything to protect a staff member from rubber hose attacks, but limiting the access of your staff members so that the information is accessed on a need-to-know basis through someone like you would help prevent sensitive data leaking. If they're attacking you, then you're fucked.

+1 for a good answer - I like the idea of having a PCI compliant expectation

Depending on the services rendered it may be more appropriate to go for PA-DSS (formerly PABP) compliance, which is similar to PCI but with a few different points. In either case, PCI or PA-DSS guidelines should be considered the minimum necessary amount of security - barely meeting either standard should not be considered acceptable.

From a consumer standpoint, PCI compliance is a useful hurdle to expect companies to meet, as it helps ensure that some amount of due diligence has been applied to security.
But note that from the standpoint of a savvy IT department, there are times that PCI can get in the way.  E.g., potentially faced with a less-skilled PCI assessor without as much understanding of the technology, sometimes PCI can lead the team on a wild goose chase, or perhaps give management an excuse to under-invest in security, feeling they only have to satisfy the assessor.  See e.g.
Does PCI compliance really reduce risk and improve security? - IT Security - Stack Exchange

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


text:
What is the easiest way to programmatically obtain the current USD-BTC spot price?
E.g., if I wanted to create a cron script that would grab the latest spot price every hour and store it in a local file or database, what would be the place to "scrape" that information from?
(Actually writing the script is not the problem, in my case.)

FYI, I ended up using the API of BitcoinCharts.com to do this.  The Mt Gox API may have worked just as well in my case, but for whatever reason, I was having an issue with my (Python) script that attempted to poll mtgox.com -- it would hang upon making the HTTPS request.

There are probably dozens of sites that now provide this data, but the CoinDesk API is one option.

You could use the JSON encoded ticker data available from MtGox at: https://mtgox.com/api/0/data/ticker.php
Just use whatever your language's equivalent to cURL or wGet is and parse as appropriate.

Unsurprisingly (to anyone familiar with the now-infamous Mt Gox saga), this method will no longer work.

You could try using www.btcrate.com as well, which supports additional currencies (should you need them).

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
Can I send bitcoins with my mobile phone?
Is it possible to send and receive bitcoins with a mobile phone? If so, are there bitcoin clients for Android or iOS?

Related: http://bitcoin.stackexchange.com/q/4214/516

Don't use Bitcoin by Bitcoin Android. It is unmaintained, it starts crashing and doesn't load anymore, and there is no way to get your bitcoins out. Someone should really get the developer to take it down. I'm emailing him again now.
Use Bitcoin Wallet. It is maintained by the same team that creates the bitcoinj android library. It is the most reliable app.
Use the MtGox mobile app. This is the best way to ensure that you do not lose coins if the app crashes, since your coins are held at mtgox.
Blockchain has a mobile wallet now as well. Looks very promising.

If you have an Android Bitcoin wallet app that ceases to work leaving you with lost coins, this article may help: http://gary-rowe.com/agilestack/2011/12/28/how-to-recover-lost-bitcoins-from-an-android-wallet/

The link to Blockchain seems to be broken.

There are at least two actual clients for Android and half a dozen "thin clients" that connect to a bitcoin server at home. As the thin clients are kind of complicated installs, I recommend Bitcoin Wallet by Andreas Schildbach.
There are a few questions of security as both apps have no way (that I'm aware of) to import/export/backup wallets and it's uncertain what level of security is held on data Google keeps in the cloud, but for carrying a small amount of coin for daily use, both are viable options.
Not being an iOS person I can't weigh in on the features etc. of the various iOS apps, but a quick glance over the various projects seems to show an assortment of thin clients and no actual iOS-based bitcoind implementation.

I have successfully used the bitcoin wallet app mentioned. I'd recommend it too.

can we get rid of this answer if it includes a recommendation for a buggy and unmaintained wallet app?

I can edit this answer per a valid recommendation. Which app listed is buggy and unmaintained?

See the comment and answer by Osmosis (Bitcoin Android). Really though, would be nice to have a couple other people weigh in here on current features/vulnerabilities of mobile clients. Also, iOS?

I can certainly vouch for Andreas Schildbach's Bitcoin Wallet - first rate.

You can also use an e-wallet or an exchange to send bitcoins. Most websites can be accessed with a phone so you don't have to install anything.
MtGox already has a mobile application that you can use to access your account. I am sure other applications and mobile sites will appear soon.

You can use BitcoinSpinner on Android phones. BitcoinSpinner is a light weight secure Bitcoin client, which is ready for use immediately after installation.
BitcoinSpinner announcement at bitcointalk.org

I want add that you can send Bitcoins from any mobile device via an SMS interface provided by PHONECO.IN. At the moment, that service only has a US phone number, so it would be relatively expensive to use from Europe.
Disclaimer: I am in no way associated with that service and I do not know anything about security, nor quality of that service.

BitPay for Android
Funds received are stored on InstaWallet, so you can spend them from any web browser as well.
https://market.android.com/details?id=com.bitcoin.bitpay&hl=en
https://en.bitcoin.it/wiki/BitPay
Though know that your funds stored on instawallet requires no password -- only the privacy of the URL is what keeps someone from spending your coins.

You may be looking for something like Qcan, they have a web app to send and receive bitcoin with your mobile number. I believe they have an Android app too.


text:
What are the privacy implications of filtered blockchain downloads?
There is now "Bloom filter" support in the network protocol for sending only relevant transactions to lightweight clients.
What are the privacy implications of the bloom filter? Does it leak any information about which keys I am interested in to the network?

It inevitably leaks information, but Bloom filters have a (controllable) false-positive rate. So a wallet client that is very concerned with privacy could make the false positive rate high enough so it becomes hard to distinguish which transactions the client was interested in.

I know it is an old question, but it deserves an updated answer.
Since the introduction of BIP37 (=SPV with bloom filters) a number of serious privacy vulnerabilities have been discovered. By using SPV + address bloom filters you are exposing all the addresses of your wallet with every Blockchain surveillance company.
The reason behind this near perfect privacy breach is the combination of network analysis and various clustering strategies.
I conducted some research on the topic, which you can check out here. This medium post includes every possible references on the topic to date, of which I'd like to highlight Nick Jonas's Privacy in BitcoinJ blog post/video presentation and research paper.
Solutions include using a full node, a full-SPV node or BIP157/BIP158 client side filtering.


text:
Can trading be done on coinbase.com?
On coinbase.com I tried to sell some bitcoins and was told I had to register a bank account.  I'd have expected that only if I were trying to withdraw dollars, euros, etc., from coinbase.  On mtgox one can sell bitcoins and have dollars in one's account.  Is that impossible on coinbase?  If so, how long does it take to move dollars to coinbase from a bank account and buy bitcoins?  If the price of a bitcoin goes up to what looks like an absurdly high price and I suspect it's a bubble that will burst, I might want to sell bitcoins and then 12 hours later, buy more at a lower price.  But if it takes a few days to get money back and forth between coinbase and a bank account, and it that must be done in order to do such trading, then coinbase is not the place to do it.
So what can and cannot be done there?

I just registered my bank account with Coinbase and bought $500 of Ethereum. I was surprised when i found out that it would take a week before I could use the Ether, like trade for Ripple which was my intent. 5 bus. days later I and saw that the withdrawal from my ban but my Coinbase account was still showing pending and that it would be two more days before the Ether would be available. I wanted to invest more but didn't want my money locked into any cryptocurrency so I transferred another $500 into a USD wallet on my Coinbase account so when the funds become available I can trade in seconds.

@AlanFisher : Might that have meant five business days, not including weekends?

Yes, I was going to say that but ran out of char's. I initiated the transfer on Thursday the 13th @ ~4 PM. Funds were withdrawn on the 17th and will not be released to me until the 20th.

Coinbase unlike Mt.Gox is not a bitcoin exchange, it is a bitcoin wallet with the option of buying or selling bitcoins using a US bank account. You can store bitcoins on the site but not USD.
This is primarily done for legal reasons. When you allow people to trade currency with each other instead of just being a currency dealer you open yourself up to a whole world of regulatory problems. Namely people would have to be extensively verified and new anti money laundering systems would have to be put in place to comply with FinCEN.

You can now hold USD on Coinbase. Read my comment on this thread for more info.

Every time you buy or sell on Coinbase, you initiate an ACH transfer. These ACH transfers take 3-7 days to complete, and many traditional banks post limits on the amount of ACH transfers you can have in a day/week/month. Too many and your bank activity will be flagged as suspicious, your funds may even be frozen.
Trade exchanges like Bitstamp and Mt. Gox function similarly to brokerage accounts. They are non-insured hot wallets that allow you to quickly trade fiat for btc without having to initiate several ACH transfers a day. You fund the exchange and they hold and track your money until you are ready to cash out. These will be your best options for frequent trading.

you might want to cite the source: http://www.reddit.com/r/Bitcoin/comments/1qaxin/psa_coinbase_is_not_an_exchange_if_you_want_to/, unless you are http://www.reddit.com/user/Coindexter

If you're day trading, you can use Coinbase's trading platform, GDAX, which is much more efficient and inexpensive than their broker/exchange system.


text:
I can see a recent blockchain.info "confirmed" transaction in a shared wallet, but I do not have a balance?
I sent 1 BTC to a shared wallet address (15wGmQqaYHhBqB6bEFvrXz4CJGNeBhQkmv) at blockchain.info. It gave me a transaction id e76ccebaaf5bf63762829a92f31a065bc4c5d623df18a79626f4276d536a625e and I can see the transaction, however the "balance" is not reflected in my wallet anywhere. What gives? I have done this successfully before and it was fast and easy. TIA

Can you clarify which wallet you use? blockchain.info does not offer shared wallets, so I'm not sure how it relates to this. Also note the later transaction that spends from this address, it could be relevant.

I don't know if you asked this question before or after transaction ae751e14246b4287e44196ec6db01e656872dd7dc3cfb68b44e931a27c431f95 happened. In that transaction, the 1 BTC associated with 15wGmQqaYHhBqB6bEFvrXz4CJGNeBhQkmv is spent, thus there are now no coins associated with it. The balance shouldn't be reflected anywhere because it is zero.

Because it is a shared wallet in the question, the balacne tracker per address is not the balance tracker per user. Shared web wallets (like ones used by exchanges) keep intenral bookkeeping of the per-user balance in the database. When some user spends Bitcoins, they are taken from any address of any incoming transaction. This makes it possible to make internal transactions for free (outside blockchain).


text:
Where in the Bitcoin Cash code is the retargetting period defined?
I'm specifically looking for the difficulty retargetting period of Bitcoin Cash, but since it is a fork of Core it should be the same code.

Looks like the answer lies here for bitcoin Cash:
https://reviews.bitcoinabc.org/rABC7ad1105f43d7bff158d4b5c882ab9bf1b74d6cce
More specifically it is here:
https://github.com/Bitcoin-ABC/bitcoin-abc/blob/master/src/pow.cpp#L73

Just FYI, when you resolve your own question, it is good to accept your answer.  Otherwise it gets "bumped" to the front page again and again because the system does not know whether the answer was satisfactory.

Albert's link shows the "emergency difficulty adjustment" code.  The basic 2016-block difficulty adjustment is defined in chainparams.cpp:
    consensus.nPowTargetTimespan = 14 * 24 * 60 * 60;

This is the desired time in seconds between difficulty adjustments.  You can also see below where they hardcode the corresponding number of blocks:
    consensus.nMinerConfirmationWindow = 2016;


text:
I have bitcoin sitting in Muskxmoon and i’m trying to withdraw it to a card or bank or something where i can have the money itself. please help
I have been trying to find a way to try and get this money (BTC) into my account or get a hold of the money. i’m sorta new to this and don’t know what to do to use this money like if i wanted to buy shoes or something. Is there anyway i can get a hold of this into my hands?

Numerous red flags suggest that the mentioned website muskxmoon dot com may be untrustworthy: the domain was only created a month ago, its site title ambiguously reads "Just a moment...", and online discussions questioning its legitimacy are prevalent. Given these signs, it's highly probable that it is a scam. Exercise extreme caution when interacting with them. Depositing ₿ or other forms of currency could result in permanent loss, as retrieval is unlikely.

Also, just as deyw already mentioned, if you have a balance there, do not ever send more money for them to allow a withdrawal. If they have your money, they could deduct any fees from that balance. Also see: https://bitcoin.stackexchange.com/q/103891/5406

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Bitcoin Core Node Stops Continuously
I've recently setup a Raspberry Pi 4 to run as a Bitcoin Core node. I've noticed that after starting Bitcoin Core is shuts down after a short period of time. My first thought was that the Pi was going to sleep so I installed xscreensaver to prevent the Pi from going to sleep. This did not solve the problem. I also read about memory potentially being an issue but the Pi has 8GB of memory so I can't imagine this is the problem. Here are the details about my set up.
Raspberry Pi 4 8BG
External SSD 1TB
Internet 500Mbps
After starting Bitcoin Core I run getblockchaininfo using bitcoin-cli and have found that my block count moves up then stops. Here are the steps at each successive restart.
359388, 438037, 443757, 444235, 444610, 444834
As you can see I get a few hundred block in most cases and then bitcoind stops. Why is bitcoind stopping and how do I get it to stay active?
Any help would be greatly appreciated.

Do you have any logs in bitcoind's debug.log (in its data directory, not sure of its location on raspiblitz).

I was able to determine the issue. The external SSD auto mount did not work properly so the drive was not seen by bitcoind. Now that I've updated the mount directory of the SSD all is working as expected.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Are two null bytes appended to the end of the Short Transaction ID?
BIP152 says not to append two null bytes on Short transaction ID, but Bitcoin for developers says to append.
Algorithm for calculating Short transaction ID in BIP152 (link):

Algorithm for calculating Short transaction ID in Bitcoin.developer ([link](Are two null bytes appended to the end of the Short Transaction ID?)):

Should we do append or not?

This is an implementation detail; it is up to you.
The short transaction ID is a 48-bit number, obtained by computing the SipHash-2-4 (a 64-bit number) as described in those documents, and setting the top two bytes (= 16 bits) to 0.
How you then store those 48 bits is up to you. You can store them in 6 bytes, or in a 64-bit integer type (as actual computer hardware generally doesn't have 48-bit integers as a native thing) whose top 16 bits will be 0.
In the BIP152 protocol message cmpctblock they are sent as 6-byte encodings.

Fine, but what about serializing and sending messages like this in reality? There must be some approach adopted by the majority (following Bitcoin core). Is append done during serialization or not (per Bitcoin core)?

I've amended my answer to address that.


text:
Is index or short transaction ID sent in getblocktxn messages?
Reading BIP152 I see that the Short Transaction ID is used in the cmpctblock message. Depending on whether the transaction is segwit or non-segwit, WTXID or TXID will be used to calculate its Short Transaction ID. What is not clear to me is whether getblocktxn meesage uses the index of the transaction or this Short Transaction ID?
In the BIP it is written that the getblocktxn message uses the following structure:

Based on that structure, indexes are sent.
However, the note for version 2 says the following:

Short transaction IDs sent to us in cmpctblock messages, and sent by
us in getblocktxn messages, are computed using the same process as in
version 1, but using the wtxid as defined in BIP 141 instead of the
txid.

It is clear to me about cmpctmessages, but it says that the Short Transaction ID is also used in getblocktxn messages?

This seems to be an erratum in that note in BIP152.
The getblocktxn message contains a BlockTransactionRequests, which contains a list of differentially encoded transaction indices (i.e., the difference between the position a given requested transaction has in the block minus the previous requested transaction's position, minus 1).

Thanks. About that differentially encoding. Does it mean that if I am sending indexes in cmpctblock or getblocktxn message for 0, 1, 34, 65, 137 and 258 transaction, I will encode it like 0, 0, 32, 34, 71 and 120?

No, as 0, 0, 32, 30, 71, 120.

Thanks. I made a mistake while calculating.


text:
Why do we need sendcmpct for getdata(CMPCT) - Low Bandwidth Relaying?
BIP152 explains two types of block announcing:

High Bandwidth Relaying (sendcmpct(1))
Low Bandwidth Relaying (sendcmpct(0))

I understand why we need sendcmpct message for the first case. In this way, we inform the peer that we want it to notify us by sending us a compact block. Similar to when we send a sendheaders message indicating that we want announcing via the header, not the inv.
I don't understand why the sendcmpct message is needed for the second case. In second case, notifying is done via header/inv, and then if we want a compact block, we need to send getdata(MSG_CMPCT_BLOCK). If we don't want to, we send MSG_BLOCK or MSG_WITNESS_BLOCK. Therefore, everything would work the same if we previously didn't send a sendcmpct message first.

sendcmpct(0) simply informs the peer that compact block support is available. Without it, the peer wouldn't know that MSG_CMPCT_BLOCK is supported by us.
So:

sendcmpct(0) means "You can ask me for compact blocks".
sendcmpct(1) means "You can ask me for compact blocks, and also please send them to me without me asking"

But if I send MSG_CMPCT_BLOCK in getdata message it means that I am supporting it (since I am requesting it). If I am not supporting it, I would not send getdata with that type, but with MSG_BLOCK or MSG_WITNESS_BLOCK. And peer would have known if it was supported based on the version when establishing the connection. If the version is greater than or equal to 70014, it means that we support it

No, sendcmpct is how you let your peer know that you support compact blocks. Protocol version 70014 simply means the sendcmpct command exists, not that compact blocks are actually supported. BIP152 states you're not allowed to use MSG_WITNESS_BLOCK or any of the other compact-block related messages unless you've received a sendcmpct message.

I thought that the version messages that are exchanged when establishing a connection between two nodes and the version field within them indicate what each node supports. I do not understand this: "Protocol version 70014 simply means the sendcmpct command exists, not that compact blocks are actually supported.". If the command exists, then compact blocks are supported?

No, if you set the protocol version to 70014, it means your software should not misbehave when it receives a sendcmpct message. You can support 70014 by just ignoring sendcmpct, and not otherwise implementing compact blocks.

Unfortunately, I don't understand the purpose of exchanging the protocol version then. The 70014 protocol version includes support for BIP152 and you say that my software should not misbehave if it receives sendcmpct message (I agree with that), but that I can support the 70014 protocol version as well by ignoring sendcmpct and not implementing BIP152 (???)? This is contradictory to me. I don't understand what does it mean? To implement other futures related to 70014?

70014 does not require you to support compact blocks. It just enables the negotiation thereof. To take an example, BIP339; it adds a feature called wtxid-based relay, in protocol 70016 or higher. It would be unacceptable if any node that wishes to support wtxid-based relay also was forced to implement compact blocks, just because there is no way to signal support for wtxidrelay without supporting compact blocks. Therefore, the protocol version number just controls which messages can be sent, but not actual feature support. That's negotiated using feature-specific messages like sendcmpct.

Ah, I think I understand now. So the version number only means that some future version "maybe" is supported by me/my peer (in sense that we can negotiate about it), but it does not necessarily mean that it is actually supported. We can establish whether something is really supported through negotiations, for example, through additional messages (eg sendcmpct) or through service flags or something else. If the version is smaller, then we don't have anything to negotiate, since that future was introduced only in the next (future) versions, which I/my peer don't even support. That's the point?


text:
How is this P2TR transaction valid?
This Taproot transaction has 3 witness items which are initial stack for P2TR script. Execution of the tapscript goes something like this:

push (4 items on the stack)
checksig operation (results in pushing 1 on the stack - we are back on a 3 items on the stack)
push an empty element (4 items on the stack)
OP_IF with an empty element as an input; it does not evaluate (3 items on the stack)
the end (3 items on the stack)

Since the consensus rule for tapscript is that execution can't result in anything but exactly one element on the stack which evaluates to true, I am asking how is this transaction valid?

There are indeed 3 witness items, but only the first of them forms the initial stack. The second is the script itself (shown in disassembled form further on the page you linked to), and the third is the taproot control block (which proves how spending with this script is permitted by the output).
There are two kinds of P2TR spends:

Key path spends, which have exactly one witness stack element.
Script path spends, which have two or more witness stack elements (the last one is the control block, the penultimate one the script, and all the ones before form the initial execution stack).

Both of these can optionally have an annex as last element, which is ignored for the purposes of determining key path vs. script path spends. The annex is characterized by starting with byte 0x50.


text:
What should I do about incoming connections if my ISP uses CGNAT?
Unfortunately, my ISP uses CGNAT, so port forwarding doesn't work. What should I do? Can I have incoming connections (since I want to open them) and how? Would a VPN help?

The most straightforward way to achieve this is by using an overlay network like Tor, i2p or Yggdrasil. Check out how to set up Tor and i2p with Bitcoin Core.
There are other services that let you bypass a NAT, like some VPNs or ngrok. But beware that (i) they may limit your reach and pick what ports you'll use (ii) they can see what you're doing, so bad for privacy.

Would a VPN help?

Some VPNs might let you accept connections through it, but most of the commercial ones don't.


text:
What am I doing wrong in calculating Merkle root of the block with only 2 transactions (block #99997)?
I want to learn how to calculate the Merkle root so I started from a simple example, a block with only 2 transactions (block #99997). However, I ran into a problem.
Mempool online block explorer says that the Merkle root of this block is: 5140e5972f672bf8e81bc189894c55a410723b095716eaeec845490aed785f0e.
However, I am getting the different value.
Two transactions are contained inside the block #99997 and their TXID are:

b86f5ef1da8ddbdb29ec269b535810ee61289eeac7bf2b2523b494551f03897c

80c6f121c3e9fe0a59177e49874d8c703cbadee0700a782e4002e87d862373c6

I did the following steps:

concatenation of transaction IDs
(result:b86f5ef1da8ddbdb29ec269b535810ee61289eeac7bf2b2523b494551f03897c80c6f121c3e9fe0a59177e49874d8c703cbadee0700a782e4002e87d862373c6)
SHA256 of the result from the step 1 (result:e08d8ecc5a02b113bea1e7e2786b8235ddb5ab6058910f30b4d966b30e484bda)
SHA256 of the result from the step 2 (result:5ab58ee21a1ae7476d59e6b7ddb05a80e8b42a4bf5748e9c5db9eb860b2bd040)

As you can see I got the different value for the Merkle root than the one presented on the Mempool site.
Mine: 5ab58ee21a1ae7476d59e6b7ddb05a80e8b42a4bf5748e9c5db9eb860b2bd040
Their: 5140e5972f672bf8e81bc189894c55a410723b095716eaeec845490aed785f0e
What am I doing wrong?

I found the solution myself. Block explorers, for some reason, displays TXIDs in reversed form, so you need to unreverse it before using.
I didn't calculate TXIDs manually, I just took them from the mempool.space, so my calculation of Merkle root went wrong. I just needed to calculate TXIDs myself or to reverse the values presented there.
Thanks to Vojtěch Strnad.

The TXID is a hash, not a number, so the concept of endianness doesn't really apply here. However, it is normally presented in reverse order (it's not completely clear why Satoshi did it this way), so you have to unreverse it before doing calculations with it.

@VojtěchStrnad I assume that he wanted to present everything in the same "reversed" way (little endian) regardless of whether it is a number or not.

@VojtěchStrnad No, I do not need to "unreverse" it. I must keep it reversed. So after calculating a TXID, it is necessary to reverse it. Mempool.space is showing as it is (without reversing).

You are right, you confused me with this "However, it is normally presented in reverse order (it's not completely clear why Satoshi did it this way).... I assumed you are talking about the way we are calculating merkle tree (since you mentioned Satoshi) and not the way it is represented in Block explorers. In block explorers it is presented in reversed form and when we are calculating merkle tree we are using "normal" form.


text:
Bitcoin core functional tests failing running on WSL2 on Windows 10
I am running this command (using a 4GB temp HD mounted):
# test/functional/test_runner.py --cachedir=/mnt/tmp/cache --tmpdir=/mnt/tmp

And for all tests I get this errors:
feature_fee_estimation.py                  | ✖ Failed  | 38 s
mempool_accept.py                          | ✖ Failed  | 6 s
mempool_limit.py                           | ✖ Failed  | 0 s
mempool_package_limits.py                  | ✖ Failed  | 1 s
mempool_sigoplimit.py                      | ✖ Failed  | 3 s
p2p_addr_relay.py                          | ✖ Failed  | 12 s
p2p_blocksonly.py                          | ✖ Failed  | 0 s
p2p_compactblocks_blocksonly.py            | ✖ Failed  | 0 s
p2p_feefilter.py                           | ✖ Failed  | 9 s
p2p_segwit.py                              | ✖ Failed  | 26 s
p2p_sendtxrcncl.py                         | ✖ Failed  | 3 s
wallet_fundrawtransaction.py --descriptors | ✖ Failed  | 10 s
wallet_miniscript.py --descriptors         | ✖ Failed  | 8 s
wallet_sendall.py --descriptors            | ✖ Failed  | 6 s

Then I got this first file to test:

feature_fee_estimation

And only for it I got this error:
2024-09-16T02:26:26.749000Z TestFramework (ERROR): Unexpected exception caught during testing
Traceback (most recent call last):
  File "/root/bitcoin-core/test/functional/test_framework/test_framework.py", line 131, in main
    self.run_test()
  File "/root/bitcoin-core/test/functional/feature_fee_estimation.py", line 434, in run_test
    self.restart_node(0, ["-blocksonly"])
  File "/root/bitcoin-core/test/functional/test_framework/test_framework.py", line 583, in restart_node
    self.start_node(i, extra_args)
  File "/root/bitcoin-core/test/functional/test_framework/test_framework.py", line 541, in start_node
    node.wait_for_rpc_connection()
  File "/root/bitcoin-core/test/functional/test_framework/test_node.py", line 257, in wait_for_rpc_connection
    raise FailedToStartError(self._node_msg(
test_framework.test_node.FailedToStartError: [node 0] bitcoind exited with status 1 during initialization. Error: -maxmempool must be at least 9 MB
************************

2024-09-16T02:26:26.800000Z TestFramework (INFO): Stopping nodes
[node 2] Cleaning up leftover process
[node 1] Cleaning up leftover process
[node 0] Cleaning up leftover process

stderr:
Traceback (most recent call last):
  File "/root/bitcoin-core/test/functional/feature_fee_estimation.py", line 441, in <module>
    EstimateFeeTest().main()
  File "/root/bitcoin-core/test/functional/test_framework/test_framework.py", line 154, in main
    exit_code = self.shutdown()
  File "/root/bitcoin-core/test/functional/test_framework/test_framework.py", line 313, in shutdown
    self.stop_nodes()
  File "/root/bitcoin-core/test/functional/test_framework/test_framework.py", line 574, in stop_nodes
    node.stop_node(wait=wait, wait_until_stopped=False)
  File "/root/bitcoin-core/test/functional/test_framework/test_node.py", line 377, in stop_node
    self.stop(wait=wait)
  File "/root/bitcoin-core/test/functional/test_framework/test_node.py", line 207, in __getattr__
    assert self.rpc_connected and self.rpc is not None, self._node_msg("Error: no RPC connection")
AssertionError: [node 0] Error: no RPC connection

I also changed my /etc/resolve.conf to this, but no success:
search localtest.me
options ndots:15
nameserver 8.8.8.8
nameserver 8.8.4.4

What else can I try to make all tests work? Thanks

"Error: -maxmempool must be at least 9 MB" ⇒ did you limit the mempool or do you think that this was an RPC failure?

I think is a RPC failure, all the other tests are working. Where can I see this maxmempool parameter?

I don't know why, but running command solved the problem:
make distclean
And then running all again

Sometimes when you have previously built from source and then pull updates to the repository, it doesn’t correctly detect all the parts that need to be rebuilt. In that case, it can help to fully reset the build and start over. It seems that this was the case here and that’s why make distclean resolved your issue.


text:
Accidently sent BTC to taproot wallet on Phantom. Wondering how i can get it back to Segwit so i can buy ordinals with it
Hey Guys i sent BTC to my Phantom Taproot account, but now i realize i should have sent it to my segwit acccount. Im wondering how i can transfer it over and if its even possible on Phantom. It was 0.2 BTC so i really hope its not a lost cause.
this is my account -  bc1pyq2d92jd-j2z5cf50w52mw97a-jgdvmkdvu687ec4h-m46kn64pteuqxl4xfk
this is the hash - 5ce798acd74293c708d7d425e93717e903d-ce6c3989d07c81c0ee9110ab06f38

Note that addresses are not accounts.
The only way to move your coins to a different address (regardless of type) is to make a transaction. Presumably the wallet you are using allows you to send Bitcoin, and presumably you are able to retrieve an address of your desired type in your target wallet. So just make a transaction sending to that address from the wallet that has your taproot address.


text:
How do I get my Bitcoin transaction confirmed?
I had a Bitcoin transaction reversal done from Cash App. And they paid the lowest fees so it has been sitting in the block chain now for over a month and it is not confirmed. How do I get it confirmed and get my funds back to my Bitcoin wallet?  Where it came from. And the amount of it is  $250.


text:
I have a wallet setup and bought Bitcoin from 2010, I remember the password.... What would I need to recover the wallet today?
What info do I need to recover my Bitcoin wallet from 2010?

sorry to say but if you only have a password its not possible to recover it
only possible options from where you can recover it is by:
1-seed phrase
2-private keys
3-a wallet backup
,The process of recovering might differ a little bit depending on the wallet application you used


text:
Can I recover wallet when lost a bitcoin core wallet dat file
I recently due to recover PC and lost the Bitcoin core recover dat file, is that possible to just using private key and address to recover it?

As you know, Bitcoin core is an HD wallet and will have many private keys and addresses derived from a master private key. The only provided way to recover the   exact same wallet is to restore a backup.
If you only want to recover control over one address, you can import the corresponding key. Bitcoin core has RPC, CLI and console interfaces that support the import of private keys or descriptors.
It might be prudent to review your backup regime too.


text:
Why are there no responses to signaling messages?
Why are there no responses to signaling messages (sendcmpct, sendheaders, wtxidrelay) that would indicate I offer a certain feature but do not want it applied to me?
What if I don't want messages to be sent to me using wtxid (only txid), but I have no problem sending wtxid to those who have sent me the wtxidrelay signal? If other node exclusively wants to communicate with nodes that will send wtxid, it will immediately reject me as unsuitable. The only signaling message that has this capability is sendcmpct (not sending it = not supporting cmpct, 0 = you will send but don't want to receive, 1 = you want both).

Most features are actually initiated by the receiver, in which case all feature negotiation does is permit (but not force) the other side to use a particular feature:

BIP144 ("Segregated Witness (Peer Services)") lets a node announce support for segwit serialized transactions/blocks using the NODE_WITNESS service flag. All this means is that the other side allowed (but not forced) to request blocks and transactions including witness data. It would be bizarre - but not impossible - to permit the other side to request witness data from you, but never ask for witness data yourself.
BIP152 ("compact blocks") are negotiated using sendcmpct. Ignoring high-bandwidth mode, sendcmpct allows (but does not force) the other side to request BIP152-encoded blocks. It is perfectly possible to announce BIP152 support, but then never request compact blocks. The high bandwidth mode is a feature on top, which is effectively equivalent to a blanket "auto-request compact blocks" for future announced blocks until further notice.
BIP111 ("NODE_BLOOM service bit") instructs nodes that support BIP37 bloom filters to set that service flag. All this means is that the other side is permitted, but not required, to use BIP37 filtering features. One can announce NODE_BLOOM without ever using the other side's filtering features (in fact, this is the case for Bitcoin Core today running with the -peerbloomfilters option).
BIP133 ("feefilter message") adds an optional feefilter message a node can send to inform the other side it is not interested in transactions with a feerate below a certain value. There is no negotiation for it, and the message is available whenever both sides indicate protocol version 70013 or higher. There is no problem with honoring incoming feefilter messages without ever sending them.
BIP157 ("Client Side Block Filtering"), like BIP111, permits but does not force a node to announce support for the filtering feature. One can support BIP157 but never use the other side's filtering feature (or care about it being offered).

In some case the feature is sender-initiated, but can still be negotiated separately in both directions:

BIP155 ("addrv2") is negotiated using a sendaddrv2 message, which permits (but does not force) the other side to send addrv2 messages instead of addr messages. From my reading, it is not an error to not send sendaddrv2 yourself, but still honor one received from the other side.
BIP130 ("sendheaders message") lets a node tell its peers that they can (but are not forced to) announce new blocks using headers rather than using inv. It is possible to not send sendheaders but still honor requests from others to receive block announcements using headers.

So I think your observation is rather the exception than the norm. There are a few features which are all-or-nothing, in that they only work if supported by both peers, which then force different behavior on both:

BIP330 ("Transaction announcement reconciliation", the protocol change side of Erlay) is negotiated using sendtxrcncl, and only takes effect when both sides support it. In this case this is a hard requirement for the protocol as it is fundamentally bidirectional: instead of announce->request, both sides build sets of to-be-announced transactions, and then they run a set reconciliation protocol between those sets. This simply makes no sense unless both sides opt into it.
BIP324 ("Version 2 P2P Encrypted Transport Protocol") fundamentally changes the protocol itself spoken between peers. It is announced using a service flag (prior to connection), but the connection attempt itself is already distinct. Earlier iterations of this idea involved starting the protocol normally, and then negotiating an upgrade, but this interfered with an important privacy design goal of the protocol. The only option is having the protocol be encrypted from the very beginning, though old peers can be detected and supported by reconnecting with the old protocol.
BIP339 ("WTXID-based relay") is negotiated using a wtxidrelay message sent in both directions. When that succeeds, both sides must announce transactions using wtxids instead of txids (but may still request using txids).

More fundamentally, the purpose of feature negotiation (rather than mandatory upgrades) is allowing client software to opt into what features they want to support individually. I don't think there is much point in adding protocol complexity to cater to the specific use case of only supporting a feature in one direction. If an implementation already bears the complexity cost of implementing the feature, why wouldn't they want to use it?


text:
Indexing Spent UTXOs
I want to do analytics on bitcoin data and for this I would need to be able to check in what tx a spent UTXO is spent.
For this Im going to index all spent UTXOs in a database and I need help with what database solution and data structure would be optimal for this.
I know there are open source solutions like the Blockstream fork of Electrs but its a bit bulky for my slim use case and my personal laptop.
I have a quite good laptop with 64GB RAM and 4TB M.2 SSD.
Any database people here with any good input?
Straight up indexing each UTXO like this {utxo_hash: hash, vout_index: index, spent_hash: hash} must be really inneficient right?
I could for example identify the utxos with block_height, tx_index, vout_index which would fit on 10 bytes instead of the 34 bytes for hash and vout_index.

"what database solution and data structure" looks like better questions for https://dba.stackexchange.com/. The particular analytics you have in mind might weigh heavily for them too.


text:
Building a CPFP raw transaction to confirm a force-closed Lightning channel
I am attempting to use bitcoin-cli createrawtransaction to build a CPFP transaction to pay for a low-fee channel close that has been unconfirmed for over a week.
I have all of the details, i.e, txid, output to spend, but as I have not attempted this before, I would like to ensure I am formatting the transaction correctly, including making it BIP 125 replaceable.
If someone who is experienced with this procedure could provide some assistance, I would appreciate a hand.

Hi Daniel, this is a self-help question and answer platform. We only deal in Q&A, posting jobs is not on-topic. Please edit your post to ask about a specific issue you are encountering, then flag your topic for reopening.


text:
Can Pending HTLC's drop my balance?
I just noticed that 2 million sat's disappeared from my balance in thunderhub. No payments or transactions have been made. Can pending HTLC's effect my balance? If Not what else could drop my balance like that? My LND node has been up constantly for 4+ months and I never seen a drop like this that hasnt came back yet. (I usually see mild fluctuations.)I see about 7 htlcs sitting in pending. Thanks I'm still very new at this and appreciate any help. I lf it keeps dropping I hate to close all my channels, it's making me a little nervous.


text:
transfer funds from regtest to real testnet
is there a way to transfer tBTC from regtest to a real testnet wallet?
I know how to create a regtest, but not (if is possible) how to transfer to testnet.

No. These are two (or more) different networks with different transactions history.

bro just did double spend on regtest: https://gist.github.com/System-Glitch/cb4e87bf1ae3fec9925725bb3ebe223a


text:
Bitcoin "stolen"
Im a bit of a noob when it comes too bitcoin but i still know some basics. I Ordered 0.00145603 bitcoin ($100AU) from Paybis and the crypto went into my account and then was taken out.

If anyone could help me it would be greatly appreciated

Sorry for your loss.
It looks like someone else has knowledge of the private key corresponding to your wallet. Most likely you downloaded malware instead of Electrum or you were tricked into using a wallet that someone else generated. Alternatively, there may be malware on your computer that extracts private keys. Either way, you should quarantine this wallet, investigate whether your computer or just the wallet is affected, and ensure that any future wallet setups are more secure.


text:
BOLT12: what is the invreq_metadata field for?
BOLT12 has a invreq_metadata field. What is this for and what are some examples of what the data in the field could look like in practice? Is this a way for a node to distinguish two different invoice_requests that it may have open for the same offer (or two different open invoice_requests that it may have open for a merchant-pays-user flow)? Or, is there some other field that is used to distinguish open invoice_requests when all other fields are the same?


text:
how is onion messaging on the lightning network incentivized?
BOLT4 defines onion routing for messages and payments in the lightning network. This is really cool. However, I'm wondering how message routing is incentivized? Payment routing seems to be clearly incentivized as each node hop gets to collect a fee, I just don't understand how the messages are incentivized.
It seems like onion messaging is starting to be used for more and more things. BOLT12 uses it to exchange invoice_requests and invoices. bLIP32 proposes doing DNS over onion messaging. As usage of onion messaging continues to grow, at what point will the current model for forwarding onion messages get abused and fail to scale and no longer work reliably? The TOR network seems to suffer this problem, it is a free service and there is no incentive for running a node, so it is very slow and unreliable because many people try to use it.

Onion routing is only taking place while transporting payments, so it is incentivized by the routing fees. AFAICT all remaining communication is gossiping, which is necessary for all clients to stay up to date with the changing state of the network. So receiving this is in the interest of every node. Now one might think about withholding attacks where a node doesn’t forward info. I’m not sure if there have been any measures implemented to protect against that, but I also don’t believe there is much to gain from such behavior, since this communication isn’t costly and the information would simply be routed around the attacker. It might become a problem if many nodes do it, though. Not sure if anybody has looked into this possibility.

I'm talking about this onion messaging: https://github.com/lightning/bolts/blame/247e83d528a2a380e533e89f31918d7b0ce6a0c1/04-onion-routing.md#L1453-L1628 . It's a new (~1.5 years) concept that doesn't involve transporting payments.


text:
can a node create two different BOLT12 offers with the same description?
Core Lightning does not seem to allow creating of two offers with the same description. At first, I thought this might be a bug. However, after looking at BOLT12, the only other unique field I see besides offer_description is offer_metadata. offer_issuer_id and/or offer_paths seem like they should be common across offers (at least offer_paths should stay the same until your path changes).
Core Lightning does not allow setting the offer_metadata field (https://docs.corelightning.org/reference/lightning-offer) when creating an offer. Also, phoenixd is even more constrained in that it only allows setting a single offer (https://phoenix.acinq.co/server/api#get-bolt12-offer) per node.
Are there any examples of how offer_metadata should be structured by an offer writer and how it should be interpreted by the offer reader? How much flexibility do we have on the data that goes in there? Is this the best field to use to make multiple unique offers with the same offer_description?


text:
will bitcoind accept, hold, and rebroadcast a 1 sat/vbyte raw transaction via the RPC for a local wallet that won't fit in the mempool when submitted?
The questions What if the mempool exceeds 300 MB? , Does my node rebroadcast its mempool transactions on startup? , Why rebroadcasting transactions in the Bitcoin Core? , and rebroadcast unconfirmed transaction suggest that bitcoin core will periodically re-broadcast a transaction from a local wallet that gets evicted from the mempool.
I'm wondering what bitcoind does if I submit a raw transaction with a minimum fee that is 1 sat/vbyte for a local watching only wallet when the mempool is full and the mempoolminfee is higher than 1 sat/vbyte? Does bitcoin core have a "special mempool" for transactions that it knows is part of its own wallet? Or, will bitcoin core reject that raw transaction? My mempool is not currently full, so I can't test this scenario. The scenario I'm asking about is different from the questions above because in the above questions, I believe the transaction fit in the mempool and was evicted, but I'm asking about if it never would have fit in the first place.
The context of this question is related to Sparrow wallet. When I use Sparrow wallet with an electrum server, the electrum server may reject transactions that won't fit in the mempool. This is very annoying because you can't submit low fee transactions when the mempool is full of high fee transactions. Electrum servers behave this way because they don't have any context of a personal wallet, so they don't want to accept a bunch of low fee transactions from everyone.
Sparrow wallet also has a mode where it will work with a local bitcoind instance using the RPC. In that case, Sparrow sets up a watching only descriptor wallet in bitcoind and lets bitcoind track the wallet for it. I'm wondering if since bitcoind is specifically tracking the Sparrow wallet, will it accept very low fee transactions, hold them, and periodically try to add them to the mempool and rebroadcast them when the mempool finally sets the mempoolminfee to a low enough value?

Transaction resubmissions is the same for all wallets, regardless of whether they are watch-only or not. If your wallet is loaded and it has unconfirmed transactions, those transactions will be resubmitted to the mempool periodically.
However, in order for a transaction to be stored in the wallet so that this resubmission can occur, it must have either been created and sent by that wallet, or made it into the mempool at some point in time so that it can be added to the wallet. If you are using the PSBT or raw transaction workflow (as you have to with a watch-only wallet), then only the latter applies as these workflows bypass the wallet's sending mechanism.
Thus for watch-only wallets, if your transaction does not make it into the mempool initially, then it will not be periodically resubmitted by the wallet as the wallet will not know about the transaction in order to do so.

Is there any interest by bitcoin core to make transactions submitted using the PSBT or raw transaction workflows notify the resubmitter logic without the transaction reaching the mempool first? Just trying to figure out if there is an intentional architectural reason for this or if it is just that no one has had time to make this capability yet. I realize there are privacy considerations for being a broadcaster of a transaction, but there could be some other reasons too. It seems to me like if a transaction is received from the RPC and not a random peer, you would want to always prioritize it.

It's an intentional decision to modularize and separate components of Bitcoin Core. As sendrawtransaction is a node RPC, it shouldn't have a direct interaction with the wallet. However, there could be a way to implement it using the new interfaces, or with a wallet specific RPC. This probably hasn't been attempted as I don't think it's something that someone has thought to ask for previously.


text:
Electrum Wallet Backup and Restore process
I guess I have misunderstood something somewhere, because this process isn't working quite as I expected. I had electrum on one laptop which I am about to reset, but before doing so, I wanted to be sure everything was backed up and running from another laptop, and now with Electrum, I went to File > Save Backup on the machine that is about to be reset, then installed electrum on the new machine, and when it asked to create a new wallet or import an existing one on its first start up, I gave it the backup file to use over the network, thinking it would then use that to install a local copy, but instead it seems to reference that backup file on the NAS every single time, and it asks for my password to access it every single time it starts ... this doesn't seem like how it should work, what am I doing wrong here?


text:
Transaction is still On hold
I was made a transaction On 11th March at 9 00pm.on my visa card address.but my transaction is still On hold.please help me about this issue


text:
bitcoin transaction stuck on bitcoin.com
transaction id - https://mempool.space/tx/af483ce44a4605a9f13faf66d37e42f574377f7a7723ada51c01f4b98aebdcca I did transaction on bitcoin.com but 28hours ago transaction pending and money deducted I am the sender and I am the receiver also.. please help me


text:
How would mining pools prevent fake hash rates from quantum computers?
This question is related to other two:
quora - How do mining pools prevent fake hash rates?
reddit - How do mining pools prevent fake hashrates?
The answers are far from being useful. For example,
One answer is:

They count the shares you found, not your hashrate.

It is well know Grover's algorithm can be used to attack SHA256
(read Applying Grover's Algorithm to Hash Functions A Software Perspective).
In practice, quantum computer hardwares are still slow and we expect they will beat classical ones in bitcoin mining in the not-too-distant future.
So why there is no way yet to prevent a quantum HONEST* attack to SHA256?
*by honest I mean just a method to find nonces by applying Grover to SHA256 and not a 51% attack.

Introduction of Quantum Resistant Hash Functions: Mining pools have the option of using specific hash functions, such as the Quantum Resistant Hash function, which is designed to be resistant to attacks by quantum computers, thus increasing the security of the hash.

This doesn't seem very helpful as an answer and looks a lot like a ChatGPT or other LLM generated answer. Which QRH do you refer to? How can it be applied by mining pools specifically? Wouldn't that affect other non-mining nodes and non-pool mining farms?

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.


text:
Can a 51% attack be triggered by any other of these 7 strategies? (and with a quantum computer?)
(I think this question will be blocked for being not specific, so help me edit it, thanks)
(I will present Facts [1] and Facts [2] which will help organize my ideas before my question)
Facts [1]: (the following information is common sense)
One possible attack is: (reproducing the words in the blog braiins)

...public keys are revealed when transactions are broadcasted to the
mempool, even BEFORE they get added to the blockchain.
If an attacker could reverse the signature and get the associated
private key during this window before the transaction gets included
on-chain, they could then broadcast a higher-fee transaction sending
the coins to themselves instead.

Facts [2]: (the difficult part of the question will start here)
The paper A Survey on Various Attacks in Bitcoin and Cryptocurrency describes 7 attacks:
A. Denial-of-service Attack
B. Double Spending Attack
C. Sybil Attack
D. Eclipse Attack
E. Selfish mining Attack
F. Fork after Withholding Attack
G. Block Withholding Attack

I finally arrive to my question:
Using a quantum computer to break SHA-256/ECDSA:
Are there other tricks to pull off a 51% attack throughout any of the (A-G) strategies?
(I have tried to find any not widespreadly diffuse knowledge, like
For example 1: In Eclipse attack, the IP address of victim person is blocked or redirected towards a competitor. IPsec uses SHA. So I think it is possible to find a vulnerability this way, but I have no idea how.
For example 2: It is written in the paper Off-Path TCP Exploits of the Mixed IPID Assignment:
"TCP connections DoS attack is particularly applicable to compromising applications secured by encrypted traffic, e.g., HTTPS and SSH".
I have tried to guess which quantum attack to sha256 is able to attack bitcoin, but I am not a computer scientist so please ANY information is wellcome)

Facts [1]:
Hashing signature were build exactly to make this as much impossible as it could.
If someone manage to reverse the signatgure before next block validation, mean he found a new way/new algorithm to break hashing (even with quantum computer).
In such scenario were SHA-256 become vulnerable, Bitcoin wont be the only priotity as many other protocols such as internet and emails also use such hashing. A new signature algorithm'd made and quickly deployed everywere.
Facts [2]:
SHA is actualy quantum proof. The brut-force duration would be reduce by orders of magnetude using Grovers alorithms on qbits, tho we are still talking about billions of years, while Bitcoin block are mined usualy in 10 minutes.
You can find interesting discution about this on quora : https://www.quora.com/How-would-quantum-computers-render-one-way-hashing-algorithms-like-SHA-256-Bitcoin-useless-Would-they-somehow-be-able-to-reverse-the-hashes-or-would-they-just-be-better-at-finding-collisions


text:
Help me recover my lost Bitcoin wallet
In 2015, I bought around 10 BTC at $400 each. I didn't realize I had them until one of these days, while going through my old Skype conversations with a friend, I found out that I had sold him a microphone in 2016, and he paid me with Crypto. That's how I remembered I had this wallet.
Unfortunately, I can't access my Bitcoins anymore. I had thrown away the laptop where I had them. I only have the Public Key and the wallet address.
Could someone please help me recover it?
Thank you.


text:
I'm trying to determine if https://web.optiontradingso.xyz/h5/#/ is legit or not. Does anyone know?
Does anyone know if https://web.optiontradingso.xyz/h5/ is legit or is it a scam?

If you have to ask that, then it is not.


text:
Which bitcoin mining pools can be used with a Bitaxe miner?
I recently acquired a Bitaxe bitcoin miner.
Which mining pools can I configure it to be used with?
It's default pool was configured to mine to https://web.public-pool.io, but when I search on that site for the bitcoin address that I specified for my payout address, no statistics of any sort appear.  I'm thinking the pool is broken somehow.  I want to try configuring the miner to use a different pool, but I don't know where to look for others.

On the bitaxe configuration, you should be using public-pool.io. Web.public-pool.io is the web page that allows you to see your unit's activity. I have four BitAxe's setup and they show up just fine, with the proper configuration.


text:
List of Bitcoin exchanges available in 2009
hope you can help. I am helping a friend to find their Bitcoin wallet. The wallet is believed to have been created in 2009 and the coins were transferred to a Bitcoin exchange.
My question is what exchanges were available back then?
My friend said that she has looked into the hacked bitcoin exchanges and claimed that she doesn’t believe her coins were lost on any of those exchanges, although she said Mt Gox looked familiar but that was not the exchange that the Bitcoins were transferred to.
Thank you in advance for the responses.

It seems there were no exchanges available in 2009.
According to cryptohopper

On March 17, 2010 Bitcoinmarket, the first cryptocurrency exchange went live.

Wikipedia says

On 18 July [2010], Mt. Gox launched its exchange

Amazon claim:

Bitstamp is the world’s oldest cryptocurrency exchange. [...]
Bitstamp was founded by Nejc Kodrič and Damijan Merlak in [August] 2011.

I guess Bitstamp is the oldest surviving Bitcoin exchange. So any money in exchanges created earlier than that is presumably lost to any account holders.


text:
Bitcoin, is this for real or not?
My sister in law believes she has bitcoin, I think she may have something also but do not know for sure,

Does this answer your question? Is there some way to safely prove that you control a certain number of Bitcoin?

Frankly, I have sincere doubts that you would have 250,000 bitcoins without knowing for sure.

Unlikely, but you can find out easy enough whether it’s real: create a wallet on your own phone (e.g. bluewallet.io for Android or Blockstream Green for iOS) and try to send 1 ₿ from your SIL’s phone to your new wallet. If you receive the 1 ₿, congratulate your SIL to an early retirement:
250,000 bitcoins are currently worth $17,500,000,000, i.e. seventeen-and-a-half billion USD.
However, I would be surprised if someone were to own 1/80th of all bitcoins in existence without knowing whether they have any bitcoins at all. I suspect that the app or website you are looking at is either a watch-only wallet that follows some exchange’s wallet, or outright malware that is showing you bogus. Either way, the most likely explanation is that what you are seeing is the outcome of someone trying to scam your SIL, likely to extract an advance fee.


text:
Piona.us did they Merge w/Bitcoin
Has their been a merger with piona.us? They want you to use them to make them your Bitcoin wallet and want a fee, plus what they want in their terms.
What happens to the blockchain that I made. When I tried to withdraw, I was transferred to pione.us. Help

Piona.us did they Merge w/Bitcoin

No.
Bitcoin is not an organisation, it cannot be merged into a business or organisation.

They want you to use them to make them your Bitcoin wallet and want a fee

Unexpected fees are generally a clear sign of deception and fraud.


text:
I'm unable to be fully synced with the lightning network
I currently have a pruned Bitcoin Core node running on my Mac, and I have lnd running too.
Everytime I run lnd, I get flooded with these error messages in terminal: Query from peer ...:8333 failed, rescheduling:did not get response before timeout
I'm apparently unable to be fully synced with the lightning network. When I type "lncli getinfo" it says "synced-to-graph = false" and "synced-to-chain = true".
Here is how my lnd.conf file looks like:

debuglevel=info
maxpendingchannels=5
alias=YourNodeAlias
color=#68F442

bitcoin.active=1
bitcoin.mainnet=1
bitcoin.node=bitcoind

bitcoind.rpchost=localhost
bitcoind.rpcuser=admin
bitcoind.rpcpass=pass123
bitcoind.zmqpubrawblock=tcp://127.0.0.1:28332
bitcoind.zmqpubrawtx=tcp://127.0.0.1:28333

Here is how my bitcoin.conf file looks like:

server=1
daemon=1
txindex=0
disablewallet=0

rpcuser=admin
rpcpassword=pass123
rpcbind=127.0.0.1
rpcallowip=127.0.0.1
rpcport=8332

dbcache=1000
maxmempool=300

listen=1
maxconnections=40

# ZMQ options
zmqpubrawblock=tcp://127.0.0.1:28332
zmqpubrawtx=tcp://127.0.0.1:28333

prune=20000

What do I need to do to fix the synced-to-graph issue? I just want to be able to run my own node and start making transactions immediately on the lightning network. Please help, been looking to fix this for many weeks.


text:
Is this a scam?
I made an account with karcof.com so someone could pay me. Once the account was created the sender sent me 41k in BTC. So now I have a balance of 41k on my karcof account. I tried to withdraw it but it said that i have to complete a Bitcoin deposit because it's considered a 3rd party transfer. The security deposit is in the amount of .006 BTC. They said once i make the BTC deposit into my account where the 41k is already at I can then withdraw the money into my account. People are telling me it's a scam, but with my own investigation I'm not sure how it could be a scam. If the BTC is already in my account then I am owner if it correct? Please help it's only $277 dollars but still that's a lot of money when you don't have any. Does it sound legit ?

This is an "advance fee fraud" scam. There is no money in your account at all. Once you pay them the 0.006 BTC fee, they'll find another excuse not to let you withdraw.


text:
Checksum of addr() descriptor
I'm trying to get the checksum of my descriptor (addr(tb1qsvmygjlhq2p9ap262fwdfq3ptfjqlg2s9gcx58wazdge07kwu26q9guuh2)) using the getdescriptorinfo method, but I'm getting an error:

-5: Address is not valid

BIP385 is too sparse to explain what's wrong with my address.
I don't have the ability to use other handle functions like wsh(), I just want to track utxo addresses on the wallet. I'm connecting to bitcoind v0.26 using Btcd Golang library

Is bitcoind running in testnet mode?

Yes, the problem was that I was accessing the regtest node. This is my carelessness, thank you. If you post it as an answer, I'll mark it as a solution.

Bitcoin Core only accepts addresses in its addr() descriptors that match the chain type it is running for.
So if bitcoind is running with e.g. -regtest, it will only accept regtest addresses, not testnet addresses.


text:
Unconfirmed transaction what to do
What does "this outpost has been spend" means? I made a transaction from my wallet to other wallet. Its been 3 days. Both wallets have "unconfirmed balance" with same amount.
When i check transaction chain my wallet +2 others have a red cross.
Is my coins still existing or they vanished?
A total noob at this btw. Also a woman. Well, u get the picture :P

This question is similar to: Why is my transaction not getting confirmed and what can I do about it?. If you believe it’s different, please edit the question, make it clear how it’s different and/or how the answers on that question are not helpful for your problem.


text:
Samourai wallet - my balance disappeared
I am/was using Samourai wallet to hold bitcoin until recently when I found out that it has been seized by the US government. I restored my wallet in Sparrow where I see much less BTC than I had in Samourai. Back in 2021 I sent 0.03 BTC, but in Sparrow it shows that I actually sent 0.11065577, the remaining 0.08059097 went to a different address, see here: https://www.blockchain.com/explorer/transactions/btc/036f6a03e8cba687256fbc2633dd218296918ff80725b0fae7154e7c39fe55e9
Could some explain why 0.08059097 disappeared and not showing up in my other wallet, although I originally only sent 0.03? Can it be revoreved? Samourai was showing the amount correctly and didn't have this problem.

"What's strange is that the output, which is supposed to represent the change, uses a different script type from the input."—It's not strange and change address is matched with output for privacy.

What's strange is that the output, which is supposed to represent the change, uses a different script type from the input. Have you tried recovering the wallet on Sparrow with other script types, specifically Nested-Segwit? If you haven't tried this yet, you need to restart the recovery process from scratch and select a different "Script Type" when creating the wallet.
If you have already tried this, on the wallet that derives from the Nested SegWit script type, try increasing the gap limit in the "Settings" tab.
If you're unsure how to do all this, I recommend an article I wrote on recovering a Samourai Wallet on Sparrow Wallet:
https://planb.network/en/tutorials/wallet/samourai-recover
If you still have access to your Samourai wallet, do you see the change UTXO on it? If yes, you can also try sending the funds directly to an address you own on another wallet, but you will need to connect to a Dojo, as Samourai's servers are no longer operational.

Your link shows
Inputs

address
amount

bc1q8w6cm5ckwen4yuc79nz8lpp0hu47evj2ky7clv
0.11065577

Outputs

address
amount
deduced purpose

3GcMjPrZCv7LNShG8tnAaYa3yTE9y4gwbr
0.03000000
Payment

3CWXMX9ryvybhEec9pFpHHBfkHjy5SefRR
0.08059097
Change returned to payer

Total
0.11059097
-

The fee paid to miners was the difference between sum of inputs and sum of outputs, 0.11065577 - 0.11059097 = 0.0000648
Everything looks normal.
An anonymous comment to another answer points out that a Samouri wallet configured to generate Segwit/Bech32 addresses for receiving money will, for example, generate P2WPKH change addresses when paying a P2WPKH address. It does this so that onlookers cannot deduce the purpose of each output from its address prefix. If the second output had a bc1 prefix, its purpose would be more obvious. Matching output address types improves privacy. This has no bearing on your problem.

in Sparrow it shows that I actually sent 0.11065577

Sparrow doesn't recognize the change address as being under its control. This typically means it doesn't have the private key for that address.

Could some explain why 0.08059097 disappeared

That 0.08059097 is change being returned to you. Since your Samouri wallet generated the address it would know that the money is returned.
If the keys for that address were not imported into Sparrow, it would not know the second output was your money.
This suggests that either the Samouri wallet backup that was imported into Sparrow was non-HD and predated the transaction or was HD but had a very large gap between seed and change address - too many generated but unused keys. Most likely it suggests that your process for "I restored my wallet in Sparrow" was incorrect or faulty.
Either way, Sparrow lacks the key generated by Samouri for the change address. Or maybe somewhere the key is associated with a descriptor for the wrong address type.
This might be evidence to support the notion that, in aggregate, sweeping is more reliable than importing?

Can it be revoreved?

Confirmed transactions are irreversible. This is a necessary feature of Bitcoin.
You don't need to reverse it, I believe you need to copy some keys from Samouri into Sparrow that were omitted in your previous work.


text:
BTC transfer fees from binance wallet to another wallet
I am new to crypto and I didn't know about transaction fees.
This is the issue I am facing:
I have bought 20 USD in BTC (0.0003) from Binance and I want to transfer it to another wallet but it's asking for a large amount of this around 5 or 6 usd as transfer fees.
I have 6 questions (The first 2 are the ones related to my issue):
1-Is there a cheaper way to transfer BTC from 1 wallet to another ? If yes how to do it with steps in Binance please.
2-If let's say I am transferreing 40 USD of BTC will the transfer fees be less or the same as the 20 USD (5 or 6 USD)?

3-Which BTC wallets are the most secure private and are open source?
4-What is the best way to buy crypto without KYC ?
5-What are the best course(s) to learn the basics of crypto in general and have a solid foundation of knowlege ?
6-How to buy monero ?
Thanks in advance

This site works best when you ask one question at a time, I suggest you edit the question to focus on one issue that is currently the most important for you.

Is there a cheaper way to transfer BTC from 1 wallet to another?

The bitcoin network has transaction fees (but does not have transfer fees). Transaction fees are effectively your bid in an auction of space in the next page of the online book of transactions called the blockchain. A complicated transaction takes more space in that page (block).
Choosing a high transaction-fee will get your transaction confirmed (i.e processed) faster.
Choosing a low transaction-fee will mean your transaction may take longer or may never get confirmed.
Many Bitcoin wallets help you set the fee appropriate to current level of activity in the Bitcoin network.
There are also websites that show current fee-rates for various desired confirmation times.

https://www.google.com/search?q=bitcoin+fee+rate+calculator+OR+estimator

If yes how to do it with steps in Binance please.

If you have problems using a service provided by a business it is best to contact the customer support service of that business directly yourself. Readers contributing answers to this self-help question&answer website generally have no special insight into the internal workings of any of the thousands of businesses that offer services related  in some way to Bitcoin.

https://www.binance.com/en/support
https://www.binance.com/en-GB/support/faq/crypto-withdrawal-fees-on-binance-d9ff84dccc24423cbe6d59859d86afe3

Binance's FAQ says

Since transaction fees are dynamic, you will be charged according to the current network conditions. The fee amount is based on an estimate of the network transaction fees and can fluctuate without notice due to factors such as network congestion. Please check the most updated fee displayed on the withdrawal page.

This doesn't make it look like Binance customers can set transaction fees lower than normal (for slower but cheaper processing in the Bitcoin network).
You may get a better answer from Binance customer support.

1 & 2. There are different fees for the different crypto exchanges(Binance, Okex, etc), so you can try different exchanges to withdraw the bitcoin. Then, if the wallet you posted here is about the web3 wallet, thus here are Unisat, and OkX wallets that most people use now. If you transfer bitcoin from one web3 wallet to another(Like from Unisat to OKX), then the fees you paid depend on the current network fee rate(maybe low or high).
3.AFAIK, the Unisat wallet is used for most web3 users, also, it's open-source.

Maybe there is no best crypto course, but in this forum(for the bitcoin), I think you should learn everything about the bitcoin first.


text:
how import in my client
bitcoin-cli -rpcwallet=leg importprunedfunds getrawtransaction gettxoutproof

after that I get only read only, what am I doing wrong?

You should be a bit more specific on what you want to do exactly. One introducing sentence would be great here. Only giving a CLI command might be okay for someone who knows exactly what you mean, but others might also be interested, especially when there's an accepted answer.

The documentation for importprunedfunds says

Imports funds without rescan. Corresponding address or script must previously be included in wallet. Aimed towards pruned wallets. The end-user is responsible to import additional transactions that subsequently spend the imported outputs or rescan after the point in the blockchain the transaction is included

(my emphasis)

Related:

Remove descriptor from a Bitcoin Core wallet
How do I import privkeys if my blockchain is pruned?


text:
How do you decide who to open lightning channels with?
I want to run my own lightning node but can’t figure out who I should be opening channels to or how much liquidity I might need.
How do you go through this decision making process? What criteria do you use to evaluate potential channel partners?


text:
Can a transaction that has been signed and broadcast to the mempool be intercepted if it uses the sighash NONE|ANYONECANPAY?
Example:
Alice creates a PSBT and signs her input using the SIGHASH_NONE | SIGHASH_ANYONECANPAY flag. She then passes this transaction to Bob. Bob adds his own input and output and signs them with the SIGHASH_ALL flag.
Question:
Is it correct to say that John or any other participant in the network could intercept this transaction in the mempool and use Alice’s input for their own purposes?

Yes, with SIGHASH_NONE | SIGHASH_ANYONECANPAY (0x82) Alice is basically giving away access to her input. Anyone could use it to build any transaction.


text:
How to verify a BTC address was generated by my private and public keys
I created a wallet using a seed phrase and a passphrase. I sent BTC to the first address listed by the wallet The BTC arrived at that address. The wallet is not now listing that address. I have the public and private keys, is it possible to verify that the address holding the BTC is a valid address for those keys?


text:
How to recover my lost seed phrase
unfortunately, I lost access to my wallet. I only remember the first 10 of the 12 word seed phrase. how do I recover the last two. lets assume my seed phrase is dinner work badge avocado object blanket together jar early mass ? ? I used BTC recover but its not working

This question is similar to: Wallet recovery phrase. If you believe it’s different, please [edit] the question, make it clear how it’s different and/or how the answers on that question are not helpful for your problem.


text:
Are there 2^160 possible addresses or 4*2^160 (4 address types) possible addresses?
Let's say Bob tells you to send him btc and he gives you a p2pkh address whose underlying 160-bit number is, say, 12345. You can't just convert that to the taproot representation of 12345 and send btc to that taproot address; Bob wouldn't receive that right?
So, effectively, for any given 160-bit number, there are 4 different addresses you can generate from it, and sending btc to one address type would indeed send only to that address type, and the other 3 would not receive it?

There are actually 5 address types commonly in use at the moment (P2PKH, P2SH, P2WPKH, P2WSH, and P2TR), and two of them encode a 32-byte (256-bit) value, not a 20-byte (160-bit) one, so the actual number of possible addresses is 2*2^256 + 3*2^160.
You technically can convert between some address types, for example both P2PKH and P2WPKH encode the same type of public key hash. However, you should never do this, because 1) the recepient will almost certainly not monitor the blockchain for payments to the converted address, and 2) they might not even be able to spend coins sent to the converted address, for example if their private key is on a hardware security module that only works for their original address type. Always send to the exact address you are given.


text:
Legit profits or likely scam?
new to bitcoin world and I got hooked up with a trader calling himself David O. Nelson and the website was MajorfxHawk.
I have doubts to it’s authenticity especially when I incurred an upgrade fee when my $1,000 investment in 5 days earned $40,000 in profits.
Repeatedly promised I would have access to profits as soon as I paid upgrade of $4,000.
It wasn’t tue and that $5,000 investment had now earned $80,000.
They just sent my profits to Coinbase wallet and I have a Withdrawal Mempool tax of nearly $4,000 which needs to be paid before I have access.
I believe this is just another step in the scam. Paying this fee does not guarantee my money does it?
My brain says if I pay, the profit will magically disappear.
I would like to hear from more experienced traders.
Thank you.

Yep. Scam. There was never any profit. You lost it all the second you sent it.

See first point at How to tell if a cryptocurrency exchange or trading platform is trustworthy?


text:
How long before my Kryptex gets updated?
I just registered and started to mine with a Xeon(R) Gold 6148 using all cores (roughly 130Ghz). How long until the Number of computers: 0 will be updated and how long until the 0.00000000 BTC balance goes up to 0.00000001 BTC with this kind of hardware?
I'm not sure if I'm allowed post what command I'm running. Maybe without my wallet name? I just want to make sure it's the correct way of running it.
The worker is doing 17000 H/s so it's not the greatest for mining I suppose.

Even a decade-old single-core CPU can do a few Mhash/s; 17000 hash/s seems wildly off if you were actually mining bitcoin. In either case, you simply cannot mine bitcoin with just a CPU and expect any income at all, you need specialized ASIC hardware these days. I have never heard about them, but consider the possibility that Kryptex might be a scam, as many mining services are.

Thanks yeah seems off. Can you suggest a known and valid and legit service i should use? Thanks

Without specialized ASIC mining hardware, you - unfortunately - should not be mining BTC at all. It's always going to be a losing effort.

how long until the 0.00000000 BTC balance goes up to 0.00000001 BTC with this kind of hardware?

Never. At 17000 H/s and current network difficulty.
See

In the ASIC-age, is it worth starting mining Bitcoin at home?
Is the native Bitcoin client intended for mining?


text:
bitcoin rpc: bitcoin-cli positive fee
Using bitcoin RPC bitcoin-cli
commands like:

listtransactions
gettransaction

can fee ever be positive?

The fee is always negative
See https://developer.bitcoin.org/reference/rpc/gettransaction.html

fee" : n,                               (numeric) The amount of the fee in BTC. This is negative and only available for the
'send' category of transactions.

Thanks a lot dear sir. Exactly but
I found some transactions in some watch-only wallets (I used descriptors) that if I check the txid in a bitcoin explorer I get a correct negative fee yet checking them using gettransaction or listtransactions in bitcoin-cli results in positive fees.
Can you provide some hints?

Do you have an example txid?

6e5fb370d70249246d53ea7aaa483a551d2e194a99b732eb8e7700f29d3c621f
there are several others


text:
BTC.com Wallet recovery
I have a revovery sheet with Encrypted Primary Seed, Backup Seed, Encrypted Recovery Secret, BTC Wallet Public Keys, Password Encrypted Secret.
I tried to use https://recovery.blocktrail.com/ and it startet to search for funds. Then I get the message that there were no funds found. I also had to input my wallet password there otherwise it will throw an error.
It says that the first address of the wallet is "X" and on that address i can see that there are still btc on it. Wallet is from 2017 I tried to import it with electrum with several derivation paths but no luck yet. Do you think the backup seed can be used and does not need to be modified or something?
Best Regards

Maybe this is obvious, but why would you try to recover a "btc.com" wallet via "blocktrail.com"? Where those two the same company?


text:
Will I have to pay taxes on bitcoin sent to a friend
A friend who resides in the UK. Had his company deposit $2,000. In my bank account.  I than bought bitcoin, and transferred this to his wallet. Would there be any taxes on this exchange, and if so am I responsible?

If you retained any part of the money in return for performing this service for your friend, then that is subject to income tax and/or capital gains tax payable by you.
But that is relatively unimportant compared to the reality of the situation. More importantly, you are either:

Being used as a money mule by criminals. By colluding with them to obscure their transactions you are making yourself part of a criminal conspiracy and may find yourself being taken to a police station to answer awkward questions about laundering stolen money associated with some crimes, perhaps really vile crimes.

Being set up as a victim of theft, the fraudulent $2000 deposit will soon be reversed by the bank but the Bitcoins you paid out will not be recoverable.

The second seems most likely and is probably the lesser of the two evils.
Yes you are responsible for your actions and answerable to both the tax authorities and the criminal justice system.
I would permanently cease all contact with this fake friend and consider reporting the deception to the relevant bank and perhaps to the local police.

See also

FBI - money mules
Is this a bitcoin scam
Friend in need


text:
Bitcoin Core release verification Umbrel Home
As it is highly recommendable to verify the release software of Bitcoin Core, I am wondering how this works with Umbrel Home. I now have the Bitcoin Core on an SSD drive which works fine, but I would like to change to the Umbrel Home server. However, if I cannot verify the Bitcoin Core software, I would have to trust Umbrel, that does not sit right with me.
Who can help me with this question?


text:
Cannot verify bitcoin core 28.0
I have completed all the steps from 0 to 9, but at step 10 when i try to verify it by doing
gpg.exe --verify SHA256SUMS.asc
i receive the response as
gpg: no signed data gpg: can't hash datafile: No data

Where do you find these steps?

Most likely OP is talking about the steps from the Windows verification instructions at https://bitcoincore.org/en/download/

It sounds like you might be missing the checksum file or signature files. Are you sure that all of the prior steps succeeded? Maybe try to go through it again and take another look at the responses for each of the steps to make sure that everything was in the right folders and nothing returned an unexpected error.
If it still does not work, please provide some information on the step that failed or other information that might help potential responders to get a sense of where the problem might be.


text:
I got emails stating I have.1.349230 BTC on the Binance Exchange. How do I find it if this is true?
I received emails stating I have 1.349230 currently sitting on the "Binance Exchange". (Payout amount: $138659.02)
To access funds in USD proceed to the cryptocurrency exchange.
How can I find this bitcoin and transfer it to my digital wallet?

Receiving unsolicited emails claiming you have significant funds on a crypto exchange like Binance is a common tactic used in phishing scams. Do Not Engage.


text:
Will a transaction without transaction fee be ignored indefinitively and never put in the blockchain?
If I broadcast a transaction of mine, and decide to not put any transaction fee, is there still an incentive for a miner to include it in to the block?
Maybe related to this, when the block itself awarded a large new amount of bitcoins when created, the so-called coinbase, would users even include a transaction fee for their transactions? And if not, then what incentivises the miners to include any transactions? Could they not just produce an empty block and get the coinbase anyway?

Transactions with a fee less than a configured minimum amount are not forwarded by many nodes, such as those based on Bitcoin Core. So such transactions will probably not ever reach a miner unless special arrangements are made directly with a miner.
Occasionally blocks are produced, even now, with no transactions in them other than the coinbase. This can happen, for example, when a miner sees a new block and so restarts mining with an empty template until a parallel process completes assembly of a set of unconfirmed transactions for a new template.
Miners mostly like free money. So they generally are somewhat inclined to also gather fee-paying transactions into their block templates as soon as possible.
They have no incentive to include transactions with zero fees if there are any other transactions they could choose instead.


text:
University Wifi blocks Mining traffic
I have several ASICs and GPUs that I want to use for mining, but the internet connection is blocking the activity. I’ve also tried using a hotspot, but for some reason, that gets blocked too.
What’s the best way to mine discreetly? Are there mining software or pools that support proxies, or would using a VPN be a better solution? If I go the VPN route, how can I connect all my miners to it effectively?


text:
I was scamed by Exopip
I got a call from Cypertrack and they say that they can help me but they need access to my wallet to close them down. The wallets are empty, is there any risk to give them this access?
Are they releable ?
Regards Jon

[Cypertrack] need access to my wallet to close [Exopip] down

That looks like nonsense to me. I would assume they are softening you up for subsequent manipulation.
Victims of scams are very often regarded as  targets by fake recovery agents.

The wallets are empty,

Wallets with a zero "balance" still contain private keys. Anyone with access to the wallet can copy those keys and later use them to steal money you later add to that wallet, even after you have changed the wallet's password.


text:
2021 Bitcoin recover funds sid to be in Binace wallet without my permission
Need help recovering Bitcoin from 2021. ledger document sent to me via email and link to transfer and withdraw funds. Large deposits recorded from 2021-2024. I was told to withdraw funds or they would be returned because of non -activity. I paid for the transfer processing, watched the funds being transferred and became suspicious. tried to stop process, one completed and process began over again. At one point it read that my bitcoin was in a Binance wallet...I contacted Binance o see if my funds were in a wallet and somehow they started me a new account saying I didnt have account or a wallet transfer. Just need to. know how to get my bitcoin deposits that I saw only a few days ago. please help!


text:
Creating a Bitcoin Payment Gateway with Electrum and python
I am trying to create a PayPal-like payment gateway for a web app developed with Django. I checked the Bitcoin website and took help from the wallet suggestion and installed Electrum according to my conditions. I searched the Electrum documentation for creating a payment gateway, but all of it is based on Electrum commands and I don't know how to execute these commands in my Python script. My main question is, is it possible to create a Bitcoin payment gateway on the Python platform? If so, do you know a solution that is as Pythonic as possible, for example with the requests library, or the Electrum library? I appreciate your valuable help in advance.

Is your goal to have a self-hosted payment processor or is your goal to build one? Are you aware of BTCPay Server?

I am new to programming so my goal is to choose a method that is simple, understandable and easy to implement. I am not familiar with BTCPay Server. Is there something similar to Electrum commands that can be used to create and send transactions to the network using a Python script? Does it provide me with servers like Electrum servers or a full node so I can run my queries?

You didn’t respond to my question. If you just want to have a payment processor to use, you can set up BTCPay Server and integrate it into your website. If you are new to programming and want to write your own payment processing software, I would recommend that you might aim for a slightly less ambitious goal first.


text:
I need Bitcoin Exodus phrase with Bitcoin inside
I lost my wallet with Bitcoin inside and am trying to recover it
But I need help doing that