Module oprf 

Oblivious Pseudorandom Function (OPRF) implementation.

OPRF allows a client to compute PRF(key, input) where:

• Server holds the secret key
• Client provides the input
• Server learns nothing about the input
• Client learns only PRF(key, input), not the key

Perfect for:

• Private rate limiting (check if user exceeded quota without revealing identity)
• Password-authenticated key exchange
• Anonymous credentials
• Privacy-preserving set membership tests

Example

use chie_crypto::oprf::{OprfServer, OprfClient};

// Server setup
let server = OprfServer::new();

// Client blind request
let input = b"user@example.com";
let (client, blinded_input) = OprfClient::blind(input);

// Server evaluates on blinded input
let blinded_output = server.evaluate(&blinded_input);

// Client unblinds to get PRF output
let prf_output = client.unblind(&blinded_output);

// Can verify this matches direct evaluation (for testing)
assert_eq!(prf_output, server.evaluate_direct(input));

Structs

BatchOprfClient

Batch OPRF client for multiple inputs.

BlindedInput

Blinded input sent from client to server.

BlindedOutput

Blinded output sent from server to client.

OprfClient

OPRF client state during the protocol.

OprfOutput

PRF output after unblinding.

OprfServer

OPRF server holding the secret key.

Enums

OprfError

OPRF error types.

Type Aliases

OprfResult