Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: BPDS: A Blockchain based Privacy-Preserving Data Sharing for Electronic
  Medical Records   Electronic medical record (EMR) is a crucial form of healthcare data,
currently drawing a lot of attention. Sharing health data is considered to be a
critical approach to improve the quality of healthcare service and reduce
medical costs. However, EMRs are fragmented across decentralized hospitals,
which hinders data sharing and puts patients' privacy at risks. To address
these issues, we propose a blockchain based privacy-preserving data sharing for
EMRs, called BPDS. In BPDS, the original EMRs are stored securely in the cloud
and the indexes are reserved in a tamper-proof consortium blockchain. By this
means, the risk of the medical data leakage could be greatly reduced, and at
the same time, the indexes in blockchain ensure that the EMRs can not be
modified arbitrarily. Secure data sharing can be accomplished automatically
according to the predefined access permissions of patients through the smart
contracts of blockchain. Besides, the joint-design of the CP-ABE-based access
control mechanism and the content extraction signature scheme provides strong
privacy preservation in data sharing. Security analysis shows that BPDS is a
secure and effective way to realize data sharing for EMRs.

16
The categories of this paper are: stat
3
The categories of this paper are: physics
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat