Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Satellite quantum communications when man-in-the-middle attacks are
  excluded   An application of quantum communications is the transmission of qubits to
create shared symmetric encryption keys in a process called Quantum Key
Distribution (QKD). Contrary to public-private key encryption, symmetric
encryption is safe from (quantum) computing attacks, i.e. it provides forward
security and is thus attractive for secure communications. In this paper we
argue that for free-space quantum communications, especially with satellites,
if one assumes that man-in-the-middle attacks can be detected by classical
channel monitoring techniques, simplified quantum communications protocols and
hardware systems can be implemented that offer improved key rates. We term
these protocols photon key distribution (PKD) to differentiate them from the
standard QKD protocols. We identify three types of photon sources and calculate
asymptotic secret key rates for PKD protocols and compare them to their QKD
counterparts. Results show that PKD protocols have roughly a factor of two
higher rates as only one measurement basis is used and due to the relaxed
security assumptions can establish keys at very high losses whereas in QKD the
privacy amplification process becomes prohibitive.

30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math