Improvement of One Adaptive Oblivious Transfer Scheme

In 2011, the authors [8] presented an adaptive oblivious transfer (OT) scheme based on Decisional 3-Party Diffie-Hellman (3DDH) assumption. The encryption used in the scheme is a combination of the Boneh-Boyen IBE scheme and a variation of the Hohenberger-Waters signature. The scheme is somewhat inefficient since it combines the two underlying schemes in a simple way. In this paper, we present an improvement of the OT scheme and show its security under 3DDH assumption. The proposed skills are helpful for designing and analyzing other cryptographic schemes.