Merge pull request #147 from tronprotocol/feature/verify_proofs

TIP-137: adjust encoding details

Author: jiangyy0824

tip-137.md

@@ -97,52 +97,71 @@ The total input length of `verifyMintProof` is 1480 bytes. For the output, `resu
 `verifyTransferProof` function is used to verify the validity of zero-knowledge proof for shielded tokens transactions.  
 
 ```
-bytes32[10][] input = abi.encode(nullifier, anchor, value_commitment, rk, zkproof);
-bytes32[9][] output = abi.encode(note_commitment, value_commitment, epk, zkproof);
+bytes32[10][] input;
 bytes32[2][] spend_authority_signature;
+bytes32[9][] output;
 (bool result, bytes memory msg) = verifyTransferProof(abi.encode(input, spend_authority_signature, output, bindingSignature, signHash, frontier, leafCount));
+
+```
+
+`input`,  `spend_authority_signature`  , and  `output` are variable length arrays.  The length of a single `input` is 320 bytes, it includes:
+
+```
+[32 bytes for nullifier][32 bytes for anchor][32 bytes for value_commitment][32 bytes for epk][32 bytes for rk][192 bytes for zkproof]
+```
+
+The length of a single `spend_authority_signature` is 64 bytes, it includes:
+
+```
+[64 bytes for spend_authority_signature]
+```
+
+The length of a single `output` is 288 bytes, it includes:
+
+```
+[32 bytes for note_commitment][32 bytes for value_commitment][32 bytes for epk][192 bytes for zkproof]
 ```
 
-The  parameters are specified as above. 
+The other parameters are: 
 
 ```
-[32 bytes for nullifier][32 bytes for anchor][32 bytes for value_commitment][32 bytes for epk][32 bytes for rk][192 bytes for zkproof][32 bytes for note_commitment][32 bytes for epk][192 bytes for zkproof][64 bytes for bindingSignature][32 bytes for signHash][1056 bytes for frontier][32 bytes for leafCount]
+[64 bytes for bindingSignature][32 bytes for signHash][1056 bytes for frontier][32 bytes for leafCount]
 ```
 
-The total input length of `verifyTransferProof` is variable. According to the input and output number in a  `transfer` transaction, there are four scenarios:
+The total input length of `verifyTransferProof` is also variable. According to the input and output number in a  `transfer` transaction, there are four scenarios:
 
 - one input and one output
 
 ```
-[320 bytes for input][288 bytes for output][64 bytes for spend_authority_signature]
+[320 bytes for input][64 bytes for spend_authority_signature][288 bytes for output]
 ```
 
-The total input length of `verifyTransferProof` is 1856 bytes.
+The original total input length is 1856 bytes. Since the special encoding rule of `abi.encode(...)` for variable arrays, the total input length of `verifyTransferProof` is 2048 bytes.
 
 - one input and two output
 
 ```
-[320 bytes for input][576 bytes for output][64 bytes for spend_authority_signature]
+[320 bytes for input][64 bytes for spend_authority_signature][576 bytes for output]
 ```
-The total input length of `verifyTransferProof` is 2144 bytes.
+The original total input length is 2144 bytes. Since the special encoding rule of `abi.encode(...)` for variable arrays, the total input length of `verifyTransferProof` is 2336 bytes.
 
 - two input and one output
 
 ```
-[640 bytes for input][288 bytes for output][128 bytes for spend_authority_signature]
+[640 bytes for input][128 bytes for spend_authority_signature][288 bytes for output]
 ```
 
-The total input length of `verifyTransferProof` is  2240 bytes.
+The original total input length is 2240 bytes. Since the special encoding rule of `abi.encode(...)` for variable arrays, the total input length of `verifyTransferProof` is 2432 bytes.
 
 - Two input and two output
 
 ```
-[640 bytes for input][576 bytes for output][128 bytes for spend_authority_signature]
+[640 bytes for input][128 bytes for spend_authority_signature][576 bytes for output]
 ```
 
-The total input length of `verifyTransferProof` is  2528 bytes.
+The original total input length is 2528 bytes. Since the special encoding rule of `abi.encode(...)` for variable arrays, the total input length of `verifyTransferProof` is 2720 bytes.
 
-For the output, `result`  is a bool value to indicate whether the proof verification succeeds. The length of `msg` is 66 ~ 1058 bytes, which returns the node value to construct the Merkle tree. The time cost of `verifyTransferProof` function takes about 10~15 ms in parallel mode.
+For the output, `result`  is a bool value to indicate whether the proof verification succeeds. The length of `msg` is 33 ~ 1058 bytes, which returns the node value to construct the Merkle tree. The time cost of `verifyTransferProof` function takes about 10~15 ms in parallel mode.
 
 （3）`verifyBurnProof`