Quantum Oblivious Transfer

Abstract

In a one-out-of-two oblivious transfer, a party Alice has two messages m ₀, m ₁ that she sends to another party Bob in such a way that he can decide to obtain either of them at his choosing, but not both. Alice never finds out which message Bob received. First introduced by Wiesner as ‘conjugate coding’, this cryptographic tool was later introduced to the world of public-key cryptography, first by Rabin (in a slightly different form) and then by Even, Goldreich and Lempel who named it after Rabin's primitive, called oblivious transfer. The one-out-of-two oblivious transfer was later shown to be extremely powerful in designing general cryptographic tools. The current paper presents a new design for a one-out-of-two oblivious transfer based on the transmission of polarized light, improving the work of Wiesner and Bennett, Brassard, Breidbart and Wiesner, and shows that the scheme is robust to general attacks.