All of the above described schemes required a hash function that had to be modeled as a random oracle to prove security. Our work utilizes recent advances in indistinguishability obfuscation to construct specific hash functions for use in these schemes. We then prove security of the original cryptosystems when instantiated with our specific hash function.
Of particular interest, our work evades the impossibility results of Dodis, Oliveira, and Pietrzak, who showed that there can be no black-box construction of hash functions that allow Full-Domain Hash Signatures to be based on trapdoor permutations, and its extension by Dodis, Haitner, and Tentes to the RSA Full-Domain Hash Signatures. This indicates that our techniques applying indistinguishability obfuscation may be useful in the future for circumventing other such black-box impossibility proofs.Category / Keywords: Original Publication (with major differences): IACR-EUROCRYPT-2014 Date: received 16 Aug 2013, last revised 26 Jan 2014 Contact author: bwaters at cs utexas edu Available format(s): PDF | BibTeX Citation Note: This is the full version of the work in Eurocrypt 2014. Version: 20140126:215523 (All versions of this report) Discussion forum: Show discussion | Start new discussion