Increase Pedersen Generator indices and subindices. (#169)

* Increase ped gen indices and subindices. * Change js circuit vk. * Update comment. * correction in comment.
AztecProtocol · Feb 27, 2023 · a1c0198 · a1c0198
1 parent f451a64
commit a1c0198
Show file tree

Hide file tree

Showing 2 changed files with 16 additions and 11 deletions.
diff --git a/cpp/src/aztec/crypto/generators/generator_data.cpp b/cpp/src/aztec/crypto/generators/generator_data.cpp
@@ -12,8 +12,8 @@ constexpr size_t num_default_generators = 2048;
 #endif
 
 constexpr size_t hash_indices_generator_offset = 2048;
-constexpr size_t num_hash_indices = 16;
-constexpr size_t num_generators_per_hash_index = 8;
+constexpr size_t num_hash_indices = 32;
+constexpr size_t num_generators_per_hash_index = 64;
 constexpr size_t num_indexed_generators = num_hash_indices * num_generators_per_hash_index;
 constexpr size_t size_of_generator_data_array = hash_indices_generator_offset + num_indexed_generators;
 constexpr size_t num_generator_types = 3;
@@ -235,21 +235,26 @@ const fixed_base_ladder* get_g1_ladder(const size_t num_bits)
 /**
  * Generator indexing:
  *
+ * Number of default generators (index = 0): N = 2048
+ * Number of hash indices: H = 32
+ * Number of sub indices for a given hash index: h = 64.
+ * Number of types of generators needed per hash index: t = 3
+ *
  * Default generators:
- * 0: P_0  P_1  P_2  ...  P_{2047}
+ * 0: P_0  P_1  P_2  ...  P_{N'-1}
  *
- * Hash-index dependent generators:
- * 1:  P_{2048 + 0*8}   P_{2049}  ...  P_{2055}
- * 2:  P_{2048 + 1*8}   P_{2048 + 1*8 + 1}   ...  P_{2048 + 1*8 + 7}
- * 3:
+ * Hash-index dependent generators: (let N' = t * N)
+ * 1:  P_{N' + 0*h*t}   P_{N' + 0*h*t + 1*t}  ...  P_{N' + 0*h*t + (h-1)*t}
+ * 2:  P_{N' + 1*h*t}   P_{N' + 1*h*t + 1*t}  ...  P_{N' + 1*h*t + (h-1)*t}
+ * 2:  P_{N' + 2*h*t}   P_{N' + 2*h*t + 1*t}  ...  P_{N' + 2*h*t + (h-1)*t}
  * 4:
  * .
  * .
  * .
- * 31: P_{2048 + 30*8}  P_{2048 + 30*8 + 1}  ...  P_{2048 + 30*8 + 7}
- * 32: P_{2048 + 31*8}  P_{2048 + 31*8 + 1}  ...  P_{2048 + 31*8 + 7}
+ * H-1:  P_{N' + (H-2)*h*t}   P_{N' + (H-2)*h*t + 1*t}  ...  P_{N' + (H-2)*h*t + (h-1)*t}
+ * H  :  P_{N' + (H-1)*h*t}   P_{N' + (H-1)*h*t + 1*t}  ...  P_{N' + (H-1)*h*t + (h-1)*t}
  *
- * Total generators = 2048 + 32*8 = 2304
+ * Total generators = (N + H * h) * t = 2304
  */
 generator_data const& get_generator_data(generator_index_t index)
 {

diff --git a/cpp/src/aztec/join_split_example/proofs/join_split/join_split.test.cpp b/cpp/src/aztec/join_split_example/proofs/join_split/join_split.test.cpp
@@ -803,7 +803,7 @@ TEST_F(join_split_tests, test_0_input_notes_and_detect_circuit_change)
     // The below part detects any changes in the join-split circuit
     constexpr uint32_t CIRCUIT_GATE_COUNT = 59175;
     constexpr uint32_t GATES_NEXT_POWER_OF_TWO = 65536;
-    const uint256_t VK_HASH("edcee79f9736d8a9dcc7a5c822a49bc930315bdad7f7b67accc60ab196eb63d9");
+    const uint256_t VK_HASH("7c5f17b829f8a6b17292a998ec06b2481abb82923e838d7422c3aec5cd5edd95");
 
     auto number_of_gates_js = result.number_of_gates;
     auto vk_hash_js = get_verification_key()->sha256_hash();