This work is about distributed protocols for oblivious transfer, proposed by Naor and Pinkas, and recently generalized by Blundo et. al. In this settings a Sender has n secrets and a Receiver is interested in one of them. The Sender distributes the information about the secrets to m servers, and a Receiver must contact a threshold of the servers in order to compute the secret. These distributed oblivious transfer protocols provide information theoretic security. We present impossibility result and lower bound for existence of one-round threshold distributed oblivious transfer protocols, generalizing the results of Blundo et. al. A threshold based construction implementing 1-out-of-n distributed oblivious transfer achieving the proved lower bound for existence is proposed. A condition for existence of general access structure distributed oblivious transfer scheme is proven. We also present a general access structure protocol implementing 1-out-of-n distributed oblivious transfer.
|Title of host publication||Progress in Cryptology (Proceedings INDOCRYPT 2002, Hyderabad, India, December 15-18, 2002)|
|Editors||A. Menezes, P. Sarkar|
|Place of Publication||Berlin|
|Publication status||Published - 2002|
|Name||Lecture Notes in Computer Science|