Simulatable Adaptive Oblivious Transfer with Statistical Receiver's Privacy

During an adaptive oblivious transfer (OT), a sender has n private documents, and a receiver can adaptively fetch k documents from them such that the sender learns nothing about the receiver’s selection and the receiver learns nothing more than those k documents. Most recent fully simulatable adaptive OT schemes are based on so-called “assisted decryption” or “blind decryption”. In this paper, we revisit another technique, “blind permute-decryption”, for designing adaptive OT. We propose an efficient generic fully simulatable oblivious transfer framework with statistical receiver’s privacy that based on “blind permute-decryption” together with three concrete installations. The first one is based on Elgamal, so the corresponding OT is secure under classical DDH assumption. The second one is based on Paillier, so the corresponding OT is secure under Decisional n-th Residuosity assumption. Besides, we introduce an extended zero-knowledge proof framework with several applications.