(chunk_bit_size: u8)
| 69 | // called decryptor which can decrypt the user id. But the verifier can't decrypt, only verify |
| 70 | |
| 71 | fn check(chunk_bit_size: u8) { |
| 72 | let mut rng = StdRng::seed_from_u64(0u64); |
| 73 | // Prover has the BBS+ signature |
| 74 | let message_count = 10; |
| 75 | let (messages, sig_params, keypair, sig) = sig_setup(&mut rng, message_count); |
| 76 | sig.verify(&messages, keypair.public_key.clone(), sig_params.clone()) |
| 77 | .unwrap(); |
| 78 | |
| 79 | // User id at message index `user_id_idx` |
| 80 | let user_id_idx = 1; |
| 81 | |
| 82 | // Decryptor creates public parameters |
| 83 | let enc_gens = EncryptionGens::<Bls12_381>::new_using_rng(&mut rng); |
| 84 | |
| 85 | // For transformed commitment to the message |
| 86 | let chunked_comm_gens = |
| 87 | ChunkedCommitmentGens::<<Bls12_381 as Pairing>::G1Affine>::new_using_rng(&mut rng); |
| 88 | |
| 89 | let (snark_srs, sk, ek, dk) = |
| 90 | setup_for_groth16(&mut rng, chunk_bit_size, &enc_gens).unwrap(); |
| 91 | let chunks_count = ek.supported_chunks_count().unwrap(); |
| 92 | |
| 93 | // Precomputation |
| 94 | let prepared_gens = PreparedEncryptionGens::from(enc_gens.clone()); |
| 95 | let prepared_ek = PreparedEncryptionKey::from(ek.clone()); |
| 96 | let prepared_dk = PreparedDecryptionKey::from(dk.clone()); |
| 97 | let pairing_powers = prepared_dk |
| 98 | .pairing_powers_given_groth16_vk(chunk_bit_size, &snark_srs.pk.vk) |
| 99 | .unwrap(); |
| 100 | |
| 101 | // User encrypts |
| 102 | let (ct, r) = Encryption::encrypt_given_snark_vk( |
| 103 | &mut rng, |
| 104 | &messages[user_id_idx], |
| 105 | &ek, |
| 106 | &snark_srs.pk.vk, |
| 107 | chunk_bit_size, |
| 108 | ) |
| 109 | .unwrap(); |
| 110 | |
| 111 | // User creates proof |
| 112 | let decomposed_message = decompose(&messages[user_id_idx], chunk_bit_size) |
| 113 | .unwrap() |
| 114 | .into_iter() |
| 115 | .map(|m| Fr::from(m as u64)) |
| 116 | .collect::<Vec<_>>(); |
| 117 | |
| 118 | let circuit = |
| 119 | BitsizeCheckCircuit::new(chunk_bit_size, None, Some(decomposed_message.clone()), true); |
| 120 | |
| 121 | let start = Instant::now(); |
| 122 | |
| 123 | let blinding = Fr::rand(&mut rng); |
| 124 | let comm_single = chunked_comm_gens |
| 125 | .G |
| 126 | .mul_bigint(messages[user_id_idx].into_bigint()) |
| 127 | .add(&(chunked_comm_gens.H.mul_bigint(blinding.into_bigint()))); |
| 128 | let comm_chunks = ChunkedCommitment::<<Bls12_381 as Pairing>::G1Affine>::new( |
no test coverage detected