BIP374: Add message to rand computation (#1758)

* BIP374: Add message to rand computation

* BIP374: Update reference and test vectors

* Add changelog

* Format changelog according to BIP3

* Add creation date

Co-authored-by: Jon Atack <[email protected]>

* Grammar fix

Co-authored-by: Jon Atack <[email protected]>

* update changelog

---------

Co-authored-by: Jon Atack <[email protected]>

Author: andrewtoth

bip-0374.mediawiki

@@ -73,12 +73,12 @@ The algorithm ''GenerateProof(a, B, r, G, m)'' is defined as:
 * Let ''A = a⋅G''.
 * Let ''C = a⋅B''.
 * Let ''t'' be the byte-wise xor of ''bytes(32, a)'' and ''hash<sub>BIP0374/aux</sub>(r)''.
-* Let ''rand = hash<sub>BIP0374/nonce</sub>(t || cbytes(A) || cbytes(C))''.
+* Let ''m' = m if m is provided, otherwise an empty byte array''.
+* Let ''rand = hash<sub>BIP0374/nonce</sub>(t || cbytes(A) || cbytes(C) || m')''.<ref name="why_include_m_in_rand"> ''' Why include the message in the rand computation?''' Not including the message in the rand compution could leak ''a'' if two proofs were constructed for the same ''a'', ''B'', and ''G'' but a different message ''m'' and an all-zero ''r''.</ref>
 * Let ''k = int(rand) mod n''.
 * Fail if ''k = 0''.
 * Let ''R<sub>1</sub> = k⋅G''.
 * Let ''R<sub>2</sub> = k⋅B''.
-* Let ''m' = m if m is provided, otherwise an empty byte array''.
 * Let ''e = int(hash<sub>BIP0374/challenge</sub>(cbytes(A) || cbytes(B) || cbytes(C) || cbytes(G) || cbytes(R<sub>1</sub>) || cbytes(R<sub>2</sub>) || m'))''.
 * Let ''s = (k + e⋅a) mod n''.
 * Let ''proof = bytes(32, e) || bytes(32, s)''.
@@ -118,6 +118,13 @@ This proposal is compatible with all older clients.
 A reference python implementation is included [https://github.com/bitcoin/bips/blob/master/bip-0374/reference.py here].
 Test vectors can be generated by running <code>./bip-0374/gen_test_vectors.py</code> which will produce a CSV file of random test vectors for both generating and verifying proofs. These can be run against the reference implementation with <code>./bip-0374/run_test_vectors.py</code>.
 
+== Changelog ==
+
+* 0.2.0 (2025-02-27):
+** Add the message to the rand computation
+* 0.1.0 (2024-12-26):
+** Initial version
+
 == Footnotes ==
 
 <references />

bip-0374/reference.py

@@ -55,11 +55,14 @@ def dleq_generate_proof(
         return None
     if B.infinity:
         return None
+    if m is not None:
+        assert len(m) == 32
     A = a * G
     C = a * B
     t = xor_bytes(a.to_bytes(32, "big"), TaggedHash(DLEQ_TAG_AUX, r))
+    m_prime = bytes([]) if m is None else m
     rand = TaggedHash(
-        DLEQ_TAG_NONCE, t + A.to_bytes_compressed() + C.to_bytes_compressed()
+        DLEQ_TAG_NONCE, t + A.to_bytes_compressed() + C.to_bytes_compressed() + m_prime
     )
     k = int.from_bytes(rand, "big") % GE.ORDER
     if k == 0:

bip-0374/test_vectors_generate_proof.csv

@@ -1,12 +1,12 @@
 index,point_G,scalar_a,point_B,auxrand_r,message,result_proof,comment
-0,02cef38f55e78b321a1f785cb1c6e33dfcef9784c18bdc4e279801c449ccdfb88e,07ff93d43f1012a5d4a44aba55240212ed39c87b3344e46757d99f24177fc576,02dad4b35c2379ba8334c9a5dda8f6e6d5cd575a7cc9d3ca4faaac51839daaa30f,cb979b0fc8ccc7f237751e719d992fcc324b6500af33999cd54a3e5c05fb1ea4,efb07d4b382d3da1079fbf24df623ba6c2e4c764993bbfa6dd7a4fe4aaf33859,51ce8becf2726c8fed85957500de5d58e0349b8ed0fe40aee2c122288ee21f8fe4d1ca31f5e3c4833fb83a654b044298aceef34881c950efefdc7b64cb5db93e,Success case 1
-1,02464e351831efedb755223cabbf664f10564b4742c725c023034bc928ed339e0e,f4e9172285393c6ada994c811b3e50fc47e96421ea7e54f4a4e459528d4cf562,03fe589b0fa23f060f6d4d1e76b9b19d5bb3db0e56d39a4303913de0e706463008,75f12482b9209dae12230ea1f8bf69723a1b447d361db8f510dd9ab33556fd4c,76184ce9eea5b339ebf5304b57452c1ada1466610f0a58574d6c496798cee04b,be01fd4ec6ee4b08adb36ddb7b0290e09710f842f8623f1afc8c0ff00bdd6cee5256b10341c30d4f393d9b2c462b1534d06e2cff60920993c6dc240806576d80,Success case 2
-2,0222db2054fef98344352a13bc0304a71da7b5e9a2f7fd1f3c9f3519a3d9377fb7,589476913e763b60d5c2a5bfb39230ec669caac1b44312e9bcd2d3f4473abfef,03bc7a19970c812118f74ba659b491e00dade6096ff62d1afe032a92b8671498ed,4da1c4c4b0f9db4eb6b2e5cb648d7e8a0aa35aa5c4ec4d07f096e0e03deca366,66503623468a78cfcef47888c85e0010ecd897f441d263448bfc7a89b882ab20,a9e3603f2cb11c74dba678448cc5bc6ae6de372502392d1914e976229cb06c401f12bd03dbab57c2cd1a209adb51c14387f82e938a8a9d363fc8dc1e76456dac,Success case 3
-3,03dfa65bd3711eba75fa1996a0c1d95a4419bd835304152d9aa6efa590670f2af6,24d0ed3fc189eb1b64e5dc9dd4af0f3c8c143b0c79cb5fcca0dfa08a11cc60a1,03b51081323d38fb0b75f0c1ec6755fdb79c239c327ca11269fe68ba8a878b704e,31a68d6db27f6404bbceff646ff1b26a34704a0105a36c5a845d0257cea19c9b,f2996b3766d123a949e65541baf1d89d446360d05af51bd93f0445d8c472c952,0dbd32f1ecd950987bda4b163e5ea536e4e43e8e2f26bcf235ff799c12089f21d5a27f90f144aaaddf5a05390c44442aa13d9fbfec8cd53d3659942617ce5cb4,Success case 4
-4,02b15de5a3aefcfe2473916c76e619b5800ac7250ef93a9e6e0dd1505104fc58e7,73fffa796edb72d111b5e0bbda1608f098ac98120796f971b438691e1bfb7b96,03a4692be176ff89a972de9cc407083096847b950d1cae72b947665a3d5f4c2f01,1cdfb4d7cce5e50783299896a471a44e6aa2c5e2100d6c37987c6b40503c6162,0ceb45f560f2cf6b76a139ffe2c47c5ca6d26d6a3a210e59f197413bbec040b4,5bd36d18c6e75e50f1fbba27596591ef3506b841ce65c8f3489fa1b31e074f0f511400ad72a06b023727809c6c16c78c5d53ff14e848184462cd357660894d3d,Success case 5
+0,02cef38f55e78b321a1f785cb1c6e33dfcef9784c18bdc4e279801c449ccdfb88e,07ff93d43f1012a5d4a44aba55240212ed39c87b3344e46757d99f24177fc576,02dad4b35c2379ba8334c9a5dda8f6e6d5cd575a7cc9d3ca4faaac51839daaa30f,cb979b0fc8ccc7f237751e719d992fcc324b6500af33999cd54a3e5c05fb1ea4,efb07d4b382d3da1079fbf24df623ba6c2e4c764993bbfa6dd7a4fe4aaf33859,7e7e934169e0bf4706e6b29e5a621c7fe199a524744a25af80071e111c0e2e94118e730d8add118dd2ee4f7d1cc183e1b87168362d1a6f85c16d8671a3fc7a8a,Success case 1
+1,02464e351831efedb755223cabbf664f10564b4742c725c023034bc928ed339e0e,f4e9172285393c6ada994c811b3e50fc47e96421ea7e54f4a4e459528d4cf562,03fe589b0fa23f060f6d4d1e76b9b19d5bb3db0e56d39a4303913de0e706463008,75f12482b9209dae12230ea1f8bf69723a1b447d361db8f510dd9ab33556fd4c,76184ce9eea5b339ebf5304b57452c1ada1466610f0a58574d6c496798cee04b,6b4521a8363a7ebc5d95ac6ec6b64db81fcf21795187d7c4600c42b73fb4fb9870ab8d106c0fd2d292c1710e10437b20575ddb3cb32eb77a5618d94ddba600f2,Success case 2
+2,0222db2054fef98344352a13bc0304a71da7b5e9a2f7fd1f3c9f3519a3d9377fb7,589476913e763b60d5c2a5bfb39230ec669caac1b44312e9bcd2d3f4473abfef,03bc7a19970c812118f74ba659b491e00dade6096ff62d1afe032a92b8671498ed,4da1c4c4b0f9db4eb6b2e5cb648d7e8a0aa35aa5c4ec4d07f096e0e03deca366,66503623468a78cfcef47888c85e0010ecd897f441d263448bfc7a89b882ab20,12aa2aa469b3c037871a09d18ab18d3840219b1ed169f6ef9deae6d927949884a459705ae89a57522224ce3482dee00a41ba511188ae60efdeb736223eb66e7b,Success case 3
+3,03dfa65bd3711eba75fa1996a0c1d95a4419bd835304152d9aa6efa590670f2af6,24d0ed3fc189eb1b64e5dc9dd4af0f3c8c143b0c79cb5fcca0dfa08a11cc60a1,03b51081323d38fb0b75f0c1ec6755fdb79c239c327ca11269fe68ba8a878b704e,31a68d6db27f6404bbceff646ff1b26a34704a0105a36c5a845d0257cea19c9b,f2996b3766d123a949e65541baf1d89d446360d05af51bd93f0445d8c472c952,7907653d29c5722ae44510e7f2839f253450aefc833b7e0a3b38384032f847f2cf41136b2fe6a558ad125287d20c0117f2a30c4ac0c4cebbcfa1dd3a69d84200,Success case 4
+4,02b15de5a3aefcfe2473916c76e619b5800ac7250ef93a9e6e0dd1505104fc58e7,73fffa796edb72d111b5e0bbda1608f098ac98120796f971b438691e1bfb7b96,03a4692be176ff89a972de9cc407083096847b950d1cae72b947665a3d5f4c2f01,1cdfb4d7cce5e50783299896a471a44e6aa2c5e2100d6c37987c6b40503c6162,0ceb45f560f2cf6b76a139ffe2c47c5ca6d26d6a3a210e59f197413bbec040b4,02277ca5a7acfe8ae13c2db4a8f74489d0ba100ed8b082381ddb6522c4510718ab88b8dbbd785c388ade79586cf6416f3c47a79670af84abccc788a5d9f2e327,Success case 5
 5,0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,c08ca8e0bb59769fc6a4e078456284e00ea34f65add988c246e1bba85824ccdc,034bccb1c570ac1f3bc42d61fe35de605b99626501ccb20297e1acbbf2d7152aa1,c8d7056abd4726eb5a0f198740af14d6c1f0c16e5d7a37eaec621b661e669ac4,,503562d36910cd2d61a4d07c8ff680265c713e63dde0dcb88e6ea3c58597bdc05b86db9af95eccc475ce2177f941c118fefed20227d4ce8ce9557cb008758de6,Success case 6
-6,0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,8e641ba6bf7f64eec76005a29585a5035376375f33e331215aedfe03b8e80e7a,0231c64e3efa506fdad6aad0f6084d5f6739de7f448d7e66f9d22f842638f41d60,02a7b2e2f5a5e9b1078dbb160502a32491fe80a091e91dd92cf77b0b7d90970f,35841ca532846e1cdd23a3d107824343584f88eff580929469865eae8355ee3c,50ae4ff80a6b339253f69f5eb6fd9d013dc9a02aef001cec08c48638c72bee5a137d150e0bb4de81b67582a992910d94df80d2f537491270026a90b56ec2b128,Success case 7
-7,0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,cfb9a7ecc49bea4f2e2ee34c38a6f48b5cd5bd06f4e4d4ffb45905b3d26db842,021cb81121a00f89769903305a367ad3cc02d5b402b12c026e06ac94bde28cd608,d38466b77484154a3fcb3151094c1c8a845c73a3c036b3a8ebffd8ef62c9047f,22616bb5fb2d7c68270f305122f2a09e833239c4b1c9a04e285119fb606ac794,bce6dfda12af1b86c1cf6c1ed627053224b6c78175eddadbe01ead836bb7772101cb330a91ef06a3f63f8254c1ac5b76e312d9dada45841ea6a9b44373819939,Success case 8
+6,0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,8e641ba6bf7f64eec76005a29585a5035376375f33e331215aedfe03b8e80e7a,0231c64e3efa506fdad6aad0f6084d5f6739de7f448d7e66f9d22f842638f41d60,02a7b2e2f5a5e9b1078dbb160502a32491fe80a091e91dd92cf77b0b7d90970f,35841ca532846e1cdd23a3d107824343584f88eff580929469865eae8355ee3c,5c7b27a33210750e9de8679d9f43497cf9f12ac642cde0a1fc26443aa2fc89bf71aabf7bac89f5d8a96cbe86daba155fa74d6f3e111136179e53b04eb6d7807f,Success case 7
+7,0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,cfb9a7ecc49bea4f2e2ee34c38a6f48b5cd5bd06f4e4d4ffb45905b3d26db842,021cb81121a00f89769903305a367ad3cc02d5b402b12c026e06ac94bde28cd608,d38466b77484154a3fcb3151094c1c8a845c73a3c036b3a8ebffd8ef62c9047f,22616bb5fb2d7c68270f305122f2a09e833239c4b1c9a04e285119fb606ac794,78a5544afa75bf152653fe55fb76926f2f65131bf090972a0b0b37d310c28a6bde0e7bfacc10ac12d36f55316ba134b6ba0b844a65ae05cad53c0b296c6639bb,Success case 8
 8,0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,0000000000000000000000000000000000000000000000000000000000000000,021cb81121a00f89769903305a367ad3cc02d5b402b12c026e06ac94bde28cd608,d38466b77484154a3fcb3151094c1c8a845c73a3c036b3a8ebffd8ef62c9047f,22616bb5fb2d7c68270f305122f2a09e833239c4b1c9a04e285119fb606ac794,INVALID,Failure case (a=0)
 9,0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141,021cb81121a00f89769903305a367ad3cc02d5b402b12c026e06ac94bde28cd608,d38466b77484154a3fcb3151094c1c8a845c73a3c036b3a8ebffd8ef62c9047f,22616bb5fb2d7c68270f305122f2a09e833239c4b1c9a04e285119fb606ac794,INVALID,Failure case (a=N [group order])
 10,0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798,cfb9a7ecc49bea4f2e2ee34c38a6f48b5cd5bd06f4e4d4ffb45905b3d26db842,INFINITY,d38466b77484154a3fcb3151094c1c8a845c73a3c036b3a8ebffd8ef62c9047f,22616bb5fb2d7c68270f305122f2a09e833239c4b1c9a04e285119fb606ac794,INVALID,Failure case (B is point at infinity)