Traceable Attribute-Based Encryption With Equality Test for Cloud Enabled E-Health System

The emerging Internet of Things (IoTs) and cloud technologies spark dramatic growth in efficiency and productivity for the conventional e-health sector. However, the extensive applications of the communication network also expose the sensitive medical data to the unprecedented cyber threats. To protect the data privacy in IoTs-based e-health cloud environments, we propose an adaptively secure data sharing scheme with traceability and equality test (T-ABEET). The T-ABEET not only allows flexible access control to the massive data but also provides the functionality of traitor tracing to identity the users who leak their decryption keys. Meanwhile, through carrying out the equality test, the target ciphertext can be retrieved efficiently without revealing anything about the plaintext. Particularly, distinct from previous traceable ABE works, the tracing cost in our T-ABEET scheme keeps constant even with the increasing number of users. Also, by introducing the multi-authority mechanism, our T-ABEET can avoid the inherent key escrow problem of ABE. Furthermore, our T-ABEET is demonstrated adaptively secure under subgroup decision assumption. Finally, performance comparison reveals that our T-ABEET has superior practicality, efficiency, and security in cloud-enabled e-health systems.