An Efficient Protocol for Restricted Adaptive Oblivious Transfer

Restricted adaptive oblivious transfer was introduced by Herranz in 2011, which is the main approach to protect user privacy in e-transactions involving operations on digital confidential data or sensitive information. There are many practical applications for restricted adaptive oblivious transfer, such as medical or financial data access, pay-per-view TV, and so on. However, so far as we know, there are only two protocols for restricted adaptive oblivious transfers which were both proposed by Herranz [8]. Furthermore, these two protocols are very expensive. In this paper, we propose a new protocol for restricted adaptive oblivious transfer by using fully homomorphic encryption. Compared with Herranz’s constructions, our protocol is more efficient in the cost of communication and computation.