chore: cleanup remaining mentions of compress with pedersen in cpp …

…and ts (#3074)

This removes all mention of the phrase compress in relation to pedersen,
execpt for one place because the code has been commented out.

I think we should likely delete that file and re-add tests. File is
`barretenberg/cpp/src/barretenberg/stdlib/commitment/pedersen/pedersen.test.cpp`

Related to #3029 


# Checklist:
Remove the checklist to signal you've completed it. Enable auto-merge if
the PR is ready to merge.
- [ ] If the pull request requires a cryptography review (e.g.
cryptographic algorithm implementations) I have added the 'crypto' tag.
- [ ] I have reviewed my diff in github, line by line and removed
unexpected formatting changes, testing logs, or commented-out code.
- [ ] Every change is related to the PR description.
- [ ] I have
[linked](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue)
this pull request to relevant issues (if any exist).

barretenberg/cpp/src/barretenberg/crypto/pedersen_commitment/c_bind.cpp

@@ -7,9 +7,9 @@ WASM_EXPORT void pedersen__init() {}
 
 WASM_EXPORT void pedersen__commit(uint8_t const* inputs_buffer, uint8_t* output)
 {
-    std::vector<grumpkin::fq> to_compress;
-    read(inputs_buffer, to_compress);
-    grumpkin::g1::affine_element pedersen_commitment = crypto::pedersen_commitment::commit_native(to_compress);
+    std::vector<grumpkin::fq> to_commit;
+    read(inputs_buffer, to_commit);
+    grumpkin::g1::affine_element pedersen_commitment = crypto::pedersen_commitment::commit_native(to_commit);
 
     serialize::write(output, pedersen_commitment);
 }

barretenberg/cpp/src/barretenberg/crypto/pedersen_commitment/c_bind_new.cpp

@@ -11,9 +11,9 @@ WASM_EXPORT void pedersen___init() {}
 
 WASM_EXPORT void pedersen___commit(fr::vec_in_buf inputs_buffer, affine_element::out_buf output)
 {
-    std::vector<grumpkin::fq> to_compress;
-    read(inputs_buffer, to_compress);
-    grumpkin::g1::affine_element pedersen_commitment = crypto::pedersen_commitment::commit_native(to_compress);
+    std::vector<grumpkin::fq> to_commit;
+    read(inputs_buffer, to_commit);
+    grumpkin::g1::affine_element pedersen_commitment = crypto::pedersen_commitment::commit_native(to_commit);
 
     serialize::write(output, pedersen_commitment);
 }

barretenberg/cpp/src/barretenberg/crypto/pedersen_hash/c_bind.cpp

@@ -9,11 +9,11 @@ WASM_EXPORT void pedersen_hash__init() {}
 
 WASM_EXPORT void pedersen__hash_with_hash_index(uint8_t const* inputs_buffer, uint32_t hash_index, uint8_t* output)
 {
-    std::vector<grumpkin::fq> to_compress;
-    read(inputs_buffer, to_compress);
+    std::vector<grumpkin::fq> to_hash;
+    read(inputs_buffer, to_hash);
     crypto::GeneratorContext<curve::Grumpkin> ctx; // todo fix
     ctx.offset = static_cast<size_t>(hash_index);
-    auto r = crypto::pedersen_hash::hash(to_compress, ctx);
+    auto r = crypto::pedersen_hash::hash(to_hash, ctx);
     barretenberg::fr::serialize_to_buffer(r, output);
 }
 }

barretenberg/cpp/src/barretenberg/crypto/pedersen_hash/c_bind_new.cpp

@@ -11,9 +11,9 @@ WASM_EXPORT void pedersen_hash_with_hash_index(uint8_t const* inputs_buffer,
                                                uint32_t const* hash_index,
                                                uint8_t* output)
 {
-    std::vector<grumpkin::fq> to_compress;
-    read(inputs_buffer, to_compress);
-    auto r = crypto::pedersen_hash::hash(to_compress, ntohl(*hash_index));
+    std::vector<grumpkin::fq> to_hash;
+    read(inputs_buffer, to_hash);
+    auto r = crypto::pedersen_hash::hash(to_hash, ntohl(*hash_index));
     barretenberg::fr::serialize_to_buffer(r, output);
 }
 }

barretenberg/cpp/src/barretenberg/join_split_example/proofs/join_split/compute_signing_data.cpp

@@ -29,11 +29,11 @@ barretenberg::fr compute_signing_data(join_split_tx const& tx)
     const auto nullifier1 = compute_nullifier(input_note_1, tx.account_private_key, tx.num_input_notes >= 1);
     const auto nullifier2 = compute_nullifier(input_note_2, tx.account_private_key, tx.num_input_notes >= 2);
 
-    std::vector<grumpkin::fq> to_compress{ public_value,  tx.public_owner,  grumpkin::fq(public_asset_id),
-                                           output_note_1, output_note_2,    nullifier1,
-                                           nullifier2,    tx.backward_link, tx.allow_chain };
+    std::vector<grumpkin::fq> to_hash{ public_value,  tx.public_owner,  grumpkin::fq(public_asset_id),
+                                       output_note_1, output_note_2,    nullifier1,
+                                       nullifier2,    tx.backward_link, tx.allow_chain };
 
-    return crypto::pedersen_hash::hash(to_compress);
+    return crypto::pedersen_hash::hash(to_hash);
 }
 
 } // namespace join_split

barretenberg/cpp/src/barretenberg/join_split_example/proofs/join_split/sign_join_split_tx.cpp

@@ -10,10 +10,10 @@ using namespace crypto::schnorr;
 
 signature sign_join_split_tx(join_split_tx const& tx, key_pair<grumpkin::fr, grumpkin::g1> const& keys)
 {
-    fr compressed = compute_signing_data(tx);
+    fr hashed = compute_signing_data(tx);
 
     std::vector<uint8_t> message(sizeof(fr));
-    fr::serialize_to_buffer(compressed, &message[0]);
+    fr::serialize_to_buffer(hashed, &message[0]);
 
     crypto::schnorr::signature signature =
         crypto::schnorr::construct_signature<Blake2sHasher, grumpkin::fq, grumpkin::fr, grumpkin::g1>(

barretenberg/cpp/src/barretenberg/join_split_example/proofs/notes/circuit/value/compute_nullifier.cpp

@@ -25,11 +25,12 @@ field_ct compute_nullifier(field_ct const& note_commitment,
         is_note_in_use,
     };
 
-    // We compress the hash_inputs with Pedersen, because that's cheaper (constraint-wise) than compressing
+    // We hash the `hash_inputs` with Pedersen, because that's cheaper (constraint-wise) than hashing
     // the data directly with Blake2s in the next step.
-    const auto compressed_inputs = pedersen_hash::hash(hash_inputs, GeneratorIndex::JOIN_SPLIT_NULLIFIER);
+    const auto hashed_inputs = pedersen_hash::hash(hash_inputs, GeneratorIndex::JOIN_SPLIT_NULLIFIER);
 
-    // Blake2s hash the compressed result. Without this it's possible to leak info from the pedersen compression.
+    // Blake2s hash the pedersen hash's result. Without this it's possible to leak info from the pedersen hash because
+    // it is not a random oracle.
     /** E.g. we can extract a representation of the hashed_pk:
      * Paraphrasing, if:
      *     nullifier = note_comm * G1 + hashed_pk * G2 + is_note_in_use * G3
@@ -38,7 +39,7 @@ field_ct compute_nullifier(field_ct const& note_commitment,
      * Notably, at the point someone withdraws, the observer would be able to connect `hashed_pk * G2` with a specific
      * eth address.
      */
-    auto blake_input = byte_array_ct(compressed_inputs);
+    auto blake_input = byte_array_ct(hashed_inputs);
     auto blake_result = proof_system::plonk::stdlib::blake2s(blake_input);
     return field_ct(blake_result);
 }

barretenberg/cpp/src/barretenberg/join_split_example/proofs/notes/native/value/compute_nullifier.cpp

@@ -24,9 +24,9 @@ fr compute_nullifier(grumpkin::fq const& note_commitment,
         hashed_pk.y,
         static_cast<int>(is_note_in_use),
     };
-    auto compressed_inputs = crypto::pedersen_hash::hash(buf, GeneratorIndex::JOIN_SPLIT_NULLIFIER);
+    auto hashed_inputs = crypto::pedersen_hash::hash(buf, GeneratorIndex::JOIN_SPLIT_NULLIFIER);
 
-    auto blake_result = blake2::blake2s(to_buffer(compressed_inputs));
+    auto blake_result = blake2::blake2s(to_buffer(hashed_inputs));
 
     return from_buffer<fr>(blake_result);
 }

barretenberg/cpp/src/barretenberg/plonk/proof_system/verification_key/verification_key.cpp

@@ -14,11 +14,10 @@ namespace proof_system::plonk {
  * defined in polynomials/evaluation_domain.hpp, and `polynomial` is a bberg library which does not depend on `crypto`
  * in its CMakeLists.txt file. (We'd need `crypto` to be able to call native pedersen functions).
  *
- * @param domain to compress
- * @param circuit_type to use when choosing pedersen compression function
- * @return barretenberg::fr compression of the evaluation domain as a field
+ * @param domain to hash
+ * @return barretenberg::fr hash of the evaluation domain as a field
  */
-barretenberg::fr hash_native_evaluation_domain(barretenberg::evaluation_domain const& domain, proof_system::CircuitType)
+barretenberg::fr hash_native_evaluation_domain(barretenberg::evaluation_domain const& domain)
 {
     barretenberg::fr out = crypto::pedersen_hash::hash({
         domain.root,
@@ -30,14 +29,14 @@ barretenberg::fr hash_native_evaluation_domain(barretenberg::evaluation_domain c
 }
 
 /**
- * @brief Compress the verification key data.
+ * @brief Hash the verification key data.
  *
- * @details Native pedersen compression of VK data that is truly core to a VK.
+ * @details Native pedersen hash of VK data that is truly core to a VK.
  * Omits recursion proof flag and recursion input indices as they are not really
  * core to the VK itself.
  *
- * @param hash_index generator index to use during pedersen compression
- * @returns a field containing the compression
+ * @param hash_index generator index to use during pedersen hashing
+ * @returns a field containing the hash
  */
 barretenberg::fr verification_key_data::hash_native(const size_t hash_index) const
 {

barretenberg/cpp/src/barretenberg/plonk/proof_system/verification_key/verification_key.test.cpp

@@ -31,12 +31,12 @@ verification_key_data rand_vk_data()
 }
 
 /**
- * @brief expect that two vk data compressions are equal for a few different hash indices
+ * @brief expect that two vk data hashes are equal for a few different hash indices
  *
  * @param vk0_data
  * @param vk1_data
  */
-void expect_compressions_eq(const verification_key_data& vk0_data, const verification_key_data& vk1_data)
+void expect_hashes_eq(const verification_key_data& vk0_data, const verification_key_data& vk1_data)
 {
     // 0 hash index
     EXPECT_EQ(vk0_data.hash_native(0), vk1_data.hash_native(0));
@@ -45,16 +45,16 @@ void expect_compressions_eq(const verification_key_data& vk0_data, const verific
 }
 
 /**
- * @brief expect that two vk data compressions are not-equal for a few different hash indices
+ * @brief expect that two vk data hashes are not-equal for a few different hash indices
  *
  * @param vk0_data
  * @param vk1_data
  */
-void expect_compressions_ne(const verification_key_data& vk0_data, const verification_key_data& vk1_data)
+void expect_hashes_ne(const verification_key_data& vk0_data, const verification_key_data& vk1_data)
 {
     EXPECT_NE(vk0_data.hash_native(0), vk1_data.hash_native(0));
     // EXPECT_NE(vk0_data.hash_native(15), vk1_data.hash_native(15));
-    // ne hash indices still lead to ne compressions
+    // ne hash indices still lead to ne hashes
     // EXPECT_NE(vk0_data.hash_native(0), vk1_data.hash_native(15));
     // EXPECT_NE(vk0_data.hash_native(14), vk1_data.hash_native(15));
 }
@@ -82,14 +82,14 @@ TEST(VerificationKey, StreamSerialization)
     EXPECT_EQ(vk_data, result);
 }
 
-TEST(VerificationKey, BasicCompressionEquality)
+TEST(VerificationKey, BasicHashEquality)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data; // copy
-    expect_compressions_eq(vk0_data, vk1_data);
+    expect_hashes_eq(vk0_data, vk1_data);
 }
 
-TEST(VerificationKey, CompressionInequalityIndexMismatch)
+TEST(VerificationKey, HashInequalityIndexMismatch)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data; // copy
@@ -98,60 +98,60 @@ TEST(VerificationKey, CompressionInequalityIndexMismatch)
     // EXPECT_NE(vk0_data.hash_native(14), vk1_data.hash_native(15));
 }
 
-TEST(VerificationKey, CompressionInequalityCircuitType)
+TEST(VerificationKey, HashInequalityCircuitType)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data; // copy
     vk0_data.circuit_type = static_cast<uint32_t>(CircuitType::ULTRA);
-    expect_compressions_ne(vk0_data, vk1_data);
+    expect_hashes_ne(vk0_data, vk1_data);
 }
 
-TEST(VerificationKey, CompressionInequalityDifferentCircuitSize)
+TEST(VerificationKey, HashInequalityDifferentCircuitSize)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data;
     vk0_data.circuit_size = 4096;
-    expect_compressions_ne(vk0_data, vk1_data);
+    expect_hashes_ne(vk0_data, vk1_data);
 }
 
-TEST(VerificationKey, CompressionInequalityDifferentNumPublicInputs)
+TEST(VerificationKey, HashInequalityDifferentNumPublicInputs)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data;
     vk0_data.num_public_inputs = 42;
-    expect_compressions_ne(vk0_data, vk1_data);
+    expect_hashes_ne(vk0_data, vk1_data);
 }
 
-TEST(VerificationKey, CompressionInequalityDifferentCommitments)
+TEST(VerificationKey, HashInequalityDifferentCommitments)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data;
     vk0_data.commitments["test1"] = g1::element::random_element();
-    expect_compressions_ne(vk0_data, vk1_data);
+    expect_hashes_ne(vk0_data, vk1_data);
 }
 
-TEST(VerificationKey, CompressionInequalityDifferentNumCommitments)
+TEST(VerificationKey, HashInequalityDifferentNumCommitments)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data;
     vk0_data.commitments["new"] = g1::element::random_element();
-    expect_compressions_ne(vk0_data, vk1_data);
+    expect_hashes_ne(vk0_data, vk1_data);
 }
 
-TEST(VerificationKey, CompressionEqualityDifferentContainsRecursiveProof)
+TEST(VerificationKey, HashEqualityDifferentContainsRecursiveProof)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data;
     vk0_data.contains_recursive_proof = false;
     vk1_data.contains_recursive_proof = true;
-    expect_compressions_eq(vk0_data, vk1_data);
+    expect_hashes_eq(vk0_data, vk1_data);
 }
 
-TEST(VerificationKey, CompressionEqualityDifferentRecursiveProofPublicInputIndices)
+TEST(VerificationKey, HashEqualityDifferentRecursiveProofPublicInputIndices)
 {
     verification_key_data vk0_data = rand_vk_data();
     verification_key_data vk1_data = vk0_data;
     vk1_data.recursive_proof_public_input_indices.push_back(42);
-    expect_compressions_eq(vk0_data, vk1_data);
+    expect_hashes_eq(vk0_data, vk1_data);
 }
 } // namespace proof_system::plonk::test_verification_key

barretenberg/cpp/src/barretenberg/stdlib/commitment/pedersen/pedersen.cpp

@@ -40,11 +40,6 @@ cycle_group<C> pedersen_commitment<C>::commit(const std::vector<std::pair<field_
     return cycle_group::batch_mul(scalars, points);
 }
 
-// template <typename C>
-// field_t<C> pedersen_commitment<C>::compress(const std::vector<field_t>& inputs, const GeneratorContext context)
-// {
-//     return commit(inputs, context).x;
-// }
 INSTANTIATE_STDLIB_TYPE(pedersen_commitment);
 
 } // namespace proof_system::plonk::stdlib

barretenberg/cpp/src/barretenberg/stdlib/recursion/verification_key/verification_key.test.cpp

@@ -63,7 +63,7 @@ TYPED_TEST(VerificationKeyFixture, VkDataVsRecursionHashNative)
 
     EXPECT_EQ(vk_data.hash_native(0), RecursVk::hash_native(native_vk, 0));
     // EXPECT_EQ(vk_data.hash_native(15), RecursVk::hash_native(native_vk, 15));
-    // // ne hash indeces still lead to ne compressions
+    // // ne hash indices still lead to ne hashes
     // EXPECT_NE(vk_data.hash_native(0), RecursVk::hash_native(native_vk, 15));
     // EXPECT_NE(vk_data.hash_native(14), RecursVk::hash_native(native_vk, 15));
 }

barretenberg/cpp/src/barretenberg/transcript/transcript.cpp

@@ -46,8 +46,8 @@ std::array<uint8_t, Keccak256Hasher::PRNG_OUTPUT_SIZE> Keccak256Hasher::hash(std
 std::array<uint8_t, Blake3sHasher::PRNG_OUTPUT_SIZE> Blake3sHasher::hash(std::vector<uint8_t> const& buffer)
 {
     grumpkin::fq input = grumpkin::fq::serialize_from_buffer(&buffer[0]);
-    grumpkin::fq compressed = crypto::pedersen_hash::hash({ input });
-    std::vector<uint8_t> res = to_buffer(compressed);
+    grumpkin::fq hashed = crypto::pedersen_hash::hash({ input });
+    std::vector<uint8_t> res = to_buffer(hashed);
     std::array<uint8_t, PRNG_OUTPUT_SIZE> result;
     for (size_t i = 0; i < PRNG_OUTPUT_SIZE; ++i) {
         result[i] = res[i];
@@ -217,8 +217,8 @@ void Transcript::apply_fiat_shamir(const std::string& challenge_name /*, const b
         break;
     }
     case HashType::PedersenBlake3s: {
-        std::vector<uint8_t> compressed_buffer = to_buffer(crypto::pedersen_hash::hash_buffer(buffer));
-        base_hash = Blake3sHasher::hash(compressed_buffer);
+        std::vector<uint8_t> hashed_buffer = to_buffer(crypto::pedersen_hash::hash_buffer(buffer));
+        base_hash = Blake3sHasher::hash(hashed_buffer);
         break;
     }
     default: {

circuits/cpp/src/aztec3/circuits/abis/c_bind.cpp

@@ -164,10 +164,10 @@ WASM_EXPORT void abis__compute_function_selector(char const* func_sig_cstr, uint
 }
 
 /**
- * @brief Hash/compress verification key data.
+ * @brief Hash verification key data.
  * This is a WASM-export that can be called from Typescript.
  *
- * @details Pedersen compress VK to use later when computing function leaf
+ * @details Pedersen hash VK to use later when computing function leaf
  * or constructor hash. Return the serialized results in the `output` buffer.
  *
  * @param vk_data_buf buffer of bytes representing serialized verification_key_data

yarn-project/aztec.js/src/account/defaults/entrypoint_payload.ts

@@ -67,7 +67,7 @@ export async function buildPayload(calls: FunctionCall[]): Promise<{
   };
 }
 
-/** Compresses an entrypoint payload to a 32-byte buffer (useful for signing) */
+/** Hashes an entrypoint payload to a 32-byte buffer (useful for signing) */
 export async function hashPayload(payload: EntrypointPayload) {
   return pedersenHashWithHashIndex(
     await CircuitsWasm.get(),

yarn-project/merkle-tree/src/test/utils/pedersen_with_counter.ts

@@ -12,7 +12,7 @@ export class PedersenWithCounter extends Pedersen {
   public hashCounter = 0;
 
   /**
-   * Compresses two 32-byte hashes.
+   * Hashes two 32-byte arrays.
    * @param lhs - The first 32-byte array.
    * @param rhs - The second 32-byte array.
    * @returns The new 32-byte hash.