Oblivious pseudorandom function

An oblivious pseudorandom function (OPRF) is a cryptographic function, similar to a keyed-hash function, but with the distinction that in an OPRF two parties cooperate to securely compute a pseudorandom function (PRF). == Definition == Specifically, an OPRF is a pseudorandom function with the following properties: The parties compute: O = OPRF(I, S) The first party (the client), knows the input (I) and learns the output (O) but does not learn the secret (S) The second party (the server), knows the secret (S), but does not learn either the input (I), nor the output (O).

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