Introduction to Cryptography with Open-Source Software

Advanced applications and protocols 371

Zero knowl edge. No information abo ut the actual result is leaked during

the protocol.

An excellent introduction to the theory of zero knowledge systems is given by

Goldreich [34].

14.3 Oblivious transfer

Oblivious transfer has much in common with zero knowledge proofs. How-

ever, here the concern is in information being sent from a “sender” to a “ re-

ceiver,” with the sender being unable to ascer tain what the receiver actually

obtains. The first protocol was developed by Rabin [74].

For Rabin’s protocol, the sender (Bob) uses an RSA encryption, and so

chooses two large primes p and q, calculates n = pq and chooses ...