Efficient Adaptively Secure IBBE From the SXDH Assumption
Somindu C. Ramanna, Palash Sarkar · IEEE Transactions on Information Theory · 2016
This paper describes the first constructions of identity-based broadcast encryption (IBBE) using Type-3 pairings, which can be proved secure against adaptive-identity attacks based on the Symmetric eXternal Diffie-Hellman assumption (which is a static, if not a standard, assumption) achieving a security degradation which is not exponential in the size of the target identity set. The constructions are obtained by extending the currently known most efficient identity-based encryption scheme proposed by Jutla and Roy in 2013. The new constructions fill both a practical and a theoretical gap in the literature on efficient IBBE schemes.