Forward-Secure Threshold Attribute-Based Signature Scheme

摘要

In an attribute-based signature (ABS) scheme, each signer is issued a private key according to his/her attributes, and can sign a message with respect to some signing predicate satisfied by his/her attributes. A recipient of the signature can verify that the signature is indeed endorsed by someone that possesses some attributes satisfying the signing predicate, without learning any information about the attributes that are utilized to produce the signature. Since the introduction of ABS, it has been well investigated in recent years. However, there are few works proposed to solve the problem of key exposure in the setting of ABS. In fact, this problem becomes more acute with the increasing tendency that unprotected and mobile devices are more and more popular. To solve the above problem, this work proposes a forward-secure ABS scheme supporting threshold predicates. The proposed scheme is proved secure under the η-Diffie-Hellman Exponent assumption without random oracles, and is also efficient in terms of communication and computation. Furthermore, it is implemented to show its practical applicability.