Expanded Framework for Dual System Encryption and Its Application
Recently, Attrapadung Eurocrypt 2014 proposed a generic framework that abstracts the concept of dual system encryption techniques. We expand their framework by proposing an extended perfect security for pair encoding scheme, which implies a new approach to employ dual system encryption methodology to obtain full security of attribute based encryption ABE system via a generic construction. Using this expanded framework, we obtain a fully secure ciphertext policy ABE CP ABE construction in composite order groups with short public parameters. Compared with previous works that either have public parameter size scaling linear with the number of attributes or require parameterized assumptions, our CP ABE system achieves the advantages of an exponential improvement in terms of public parameter size and static assumptions relied on simultaneously.
ICISC