Public Key Timed-Release Attribute-Based Encryption

This paper introduces and explores a new concept of public key timed-release attribute-based encryption (PKTRABE) which can be used to solve the time-dependent ABE problem. In our PKTRABE model, the sender encrypts a message so that only the intended receivers who own some specified attributes can decrypt it after a specified time in the future. We begin by explaining what is PKTRABE. Then, we formalize the notion of basic PKTRABE and its security game model. Finally, we give two concrete schemes which are secure under the BDH and DBDH assumption in the random oracle model. Conclusions and future work are also summarized.