Attribute-Based Encryption for Access Control Using Elementary Operations

Attribute-based encryption (ABE) has attracted considerable attention in the research community in recent years. It has a number of applications such as broadcast encryption and the cryptographic enforcement of access control policies. Existing instantiations of ABE make use of access structures encoded either as trees of Shamir threshold secret-sharing schemes or monotone span programs. In both cases, the appropriate computations for these schemes are interleaved with the standard operations for cryptographic pairings. Moreover, the resulting schemes are not particularly appropriate for access control policies. In this paper, therefore, we start by examining the representation of access control policies and investigate alternative secret-sharing schemes that could be used to enforce them. We develop new ABE schemes based on the Benaloh-Leichter scheme, which employs only elementary arithmetic operations, and then extend this to arbitrary linear secret-sharing schemes. We then compare the complexity of existing schemes with our scheme based on Benaloh-Leichter.