1. MeDShare: Trust-Less Medical Data Sharing Among Cloud Service Providers via Blockchain
Source: IEEE Access, Vol. 5, pp –14767, July 2017.
Author: Qi Xia, Emmanuel Boateng Sifah, Kwame Omono Asamoah,
Jianbin Gao, Xiaojiang Du, and Mohsen Guizani
Speaker: Joyun Liu
Date: 09/18/2018

2. Outline Introduction Related works Proposed scheme Security analysis
- Blockchain
- Smart contract
Proposed scheme
Security analysis
Discussion
Conclusions

3. Introduction Hospital 1 Medical data Hospital 2 System
Medical researcher
Medical data
介紹每個角色
介紹流程
Hospital 3
Blockchain
Medical data
Smart contract

4. Related works(1/2) - Blockchain
Decentralization
Immutability
Bob gives Alice 10 dollars.
Blockchain

5. Related works(2/2) - Smart contract
Money
Drink

6. Existing database infrastructure
Proposed scheme(1/5)
Requestors
Querying
system
Trigger
Processing and
consensus nodes
Authenticator
Form
h(requestor ID)
h(timestamp)
Requestor public key
Existing database infrastructure
Requestor private key
System

7. Tag : Sensitivity = High
Proposed scheme(2/5)
Processing and
consensus nodes
Existing database
infrastructure #A
Payload
Request data
nID
rID
Form #B
Payload #C
Payload
Output data #D
Payload
nID
#D’
Payload
Tag : Sensitivity = High
nID
#D’
Payload
System

8. Proposed scheme(3/5) System Requestor public key Requestor private key
Contract key
Proposed scheme(3/5)
Package
Data ID
Data
Smart contract
Processing and
consensus nodes
Authenticator
Package
Data ID
Encrypted data
Smart contract
Contract key
Smart contract
center
Blockchain
network
Form
System

9. Proposed scheme(4/5) Requestors System Requestor public key
Requestor private key
Contract key
Proposed scheme(4/5)
Requestors
Querying
system
Trigger
Processing and
consensus nodes
Authenticator
Package
Data ID
Encrypted data
Smart contract
Encrypted package
Data ID
Encrypted data
Smart contract
Package
Data ID
Encrypted data
Smart contract
System

10. Proposed scheme(5/5) getAction() getSensitivity() accessControl()
Requestor public key
Requestor private key
Contract key
Proposed scheme(5/5)
Requestors
Querying
system
Trigger
Processing and
consensus nodes
data
Smart contract
Blockchain
network
Smart contract
center
getAction()
getSensitivity()
accessControl()
System

11. Security analysis Malicious access System Requestor public key
Requestor private key
Contract key
Malicious access
Processing and
consensus nodes
Authenticator
Contract key
Blockchain
network
System

12. Discussion request User System data
[26] T. Hardjono and N. Smith, “Cloud-based commissioning of constrained devices using permissioned blockchains,'' in Proc. 2nd ACMInt.Workshop IoT Privacy, Trust, Secur.
(IoTPTS), 2016, pp
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pp , Jul./Aug
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[29] Q. Xia, E. B. Sifah, A. Smahi, S. Amofa, and X. Zhang, “BBDS: Blockchain-based data sharing for electronic medical records in cloud environments,'' Information, vol. 8,
no. 2, p. 44, 2017.
[30] S. Ferdous, A. Margheri, F. Paci, and V. Sassone, “Decentralised runtime monitoring for access control systems in cloud federations,'' in Proc. IEEE Int. Conf. Distrib. Comput.,
Jun. 2017, pp
[31] M. M. Hassan, K. Lin, X. Yue, and J.Wan, “A multimedia healthcare data sharing approach through cloud-based body area network,'' Future Gener. Comput. Syst., vol. 66,
pp , Jan

13. Conclusions
Data privacy
Effectively trace
Revoke access

14. Existing database infrastructure
System model
Querying
system
Trigger
Processing and
consensus nodes
Authenticator
User
Existing database infrastructure
Smart contract
center
Blockchain
network
System