Introduction
Abstract
This document proposes additional fields for BIP 174 PSBTv0 and BIP 370 PSBTv2 that allow for BIP 340/341/342 Taproot data to be included in a PSBT of any version. These will be fields for signatures and scripts that are relevant to the creation of Taproot inputs.
Copyright
This BIP is licensed under the 2-clause BSD license.
Motivation
BIPs 340, 341, and 342 specify Taproot which provides a wholly new way to create and spend Bitcoin outputs. The existing PSBT fields are unable to support Taproot due to the new signature algorithm and the method by which scripts are embedded inside of a Taproot output. Therefore new fields must be defined to allow PSBTs to carry the information necessary for signing Taproot inputs.
Specification
The new per-input types are defined as follows:
Name |
<keytype> |
<keydata> |
<keydata> Description |
<valuedata> |
<valuedata> Description |
Versions Requiring Inclusion |
Versions Requiring Exclusion |
Versions Allowing Inclusion |
|---|---|---|---|---|---|---|---|---|
Taproot Key Spend Signature |
|
None |
No key data [1] |
|
The 64 or 65 byte Schnorr signature for key path spending a Taproot output. Finalizers should remove this field after |
0, 2 |
||
Taproot Script Spend Signature |
|
<xonlypubkey> |
A 32 byte X-only public key involved in a leaf script concatenated with the 32 byte hash of the leaf it is part of. |
|
The 64 or 65 byte Schnorr signature for this pubkey and leaf combination. Finalizers should remove this field after |
0, 2 |
||
Taproot Leaf Script |
|
<bytes control block> |
The control block for this leaf as specified in BIP 341. The control block contains the merkle tree path to this leaf. |
<bytes script> |
The script for this leaf as would be provided in the witness stack followed by the single byte leaf version. Note that the leaves included in this field should be those that the signers of this input are expected to be able to sign for. Finalizers should remove this field after |
0, 2 |
||
Taproot Key BIP 32 Derivation Path |
|
|
A 32 byte X-only public key involved in this input. It may be the output key, the internal key, or a key present in a leaf script. |
<compact size uint number of hashes> |
A compact size unsigned integer representing the number of leaf hashes, followed by a list of leaf hashes, followed by the 4 byte master key fingerprint concatenated with the derivation path of the public key. The derivation path is represented as 32-bit little endian unsigned integer indexes concatenated with each other. Public keys are those needed to spend this output. The leaf hashes are of the leaves which involve this public key. The internal key does not have leaf hashes, so can be indicated with a |
0, 2 |
||
Taproot Internal Key |
|
None |
No key data |
|
The X-only pubkey used as the internal key in this output.[2] Finalizers should remove this field after |
0, 2 |
||
Taproot Merkle Root |
|
None |
No key data |
|
The 32 byte Merkle root hash. Finalizers should remove this field after |
0, 2 |
The new per-output types are defined as follows:
Name |
<keytype> |
<keydata> |
<keydata> Description |
<valuedata> |
<valuedata> Description |
Versions Requiring Inclusion |
Versions Requiring Exclusion |
Versions Allowing Inclusion |
|---|---|---|---|---|---|---|---|---|
Taproot Internal Key |
|
None |
No key data |
|
The X-only pubkey used as the internal key in this output. |
0, 2 |
||
Taproot Tree |
|
None |
No key data |
|
One or more tuples representing the depth, leaf version, and script for a leaf in the Taproot tree, allowing the entire tree to be reconstructed. The tuples must be in depth first search order so that the tree is correctly reconstructed. Each tuple is an 8-bit unsigned integer representing the depth in the Taproot tree for this script, an 8-bit unsigned integer representing the leaf version, the length of the script as a compact size unsigned integer, and the script itself. |
0, 2 |
||
Taproot Key BIP 32 Derivation Path |
|
|
A 32 byte X-only public key involved in this output. It may be the output key, the internal key, or a key present in a leaf script. |
<compact size uint number of hashes> |
A compact size unsigned integer representing the number of leaf hashes, followed by a list of leaf hashes, followed by the 4 byte master key fingerprint concatenated with the derivation path of the public key. The derivation path is represented as 32-bit little endian unsigned integer indexes concatenated with each other. Public keys are those needed to spend this output. The leaf hashes are of the leaves which involve this public key. The internal key does not have leaf hashes, so can be indicated with a |
0, 2 |
UTXO Types
BIP 174 recommends using PSBT_IN_NON_WITNESS_UTXO for all inputs because of potential attacks involving an updater lying about the amounts in an output. Because a Taproot signature will commit to all of the amounts and output scripts spent by the inputs of the transaction, such attacks are prevented as any such lying would result in an invalid signature. Thus Taproot inputs can use just PSBT_IN_WITNESS_UTXO.
Compatibility
These are simply new fields added to the existing PSBT format. Because PSBT is designed to be extensible, old software will ignore the new fields.
Test Vectors
The following are invalid PSBTs:
- Case: PSBT With
PSBT_IN_TAP_INTERNAL_KEYkey that is too long (incorrectly serialized as compressed DER)- Bytes in Hex:
Base64 String:
cHNidP8BAHECAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////Anh8AQAAAAAAFgAUg6fjS9mf8DpJYu+KGhAbspVGHs5gawQqAQAAABYAFHrDad8bIOAz1hFmI5V7CsSfPFLoAAAAAAABASsA8gUqAQAAACJRIFosLPW1LPMfg60ujaY/8DGD7Nj2CcdRCuikjgORCgdXARchAv40kGTJjW4qhT+jybEr2LMEoZwZXGDvp+4jkwRtP6IyAAAA
- Case: PSBT With
PSBT_IN_TAP_KEY_SIGsignature that is too shortBytes in Hex:
<70736274ff010071020000000127744ababf3027fe0d6cf23a96eee2efb188ef52301954585883e69b6624b2420000000000ffffffff02787c01000000000016001483a7e34bd99ff03a4962ef8a1a101bb295461ece606b042a010000001600147ac369df1b20e033d6116623957b0ac49f3c52e8000000000001012b00f2052a010000002251205a2c2cf5b52cf31f83ad2e8da63ff03183ecd8f609c7510ae8a48e03910a075701133f173bb3d36c074afb716fec6307a069a2e450b995f3c82785945ab8df0e24260dcd703b0cbf34de399184a9481ac2b3586db6601f026a77f7e4938481bc3475000000Base64 String:
cHNidP8BAHECAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////Anh8AQAAAAAAFgAUg6fjS9mf8DpJYu+KGhAbspVGHs5gawQqAQAAABYAFHrDad8bIOAz1hFmI5V7CsSfPFLoAAAAAAABASsA8gUqAQAAACJRIFosLPW1LPMfg60ujaY/8DGD7Nj2CcdRCuikjgORCgdXARM/Fzuz02wHSvtxb+xjB6BpouRQuZXzyCeFlFq43w4kJg3NcDsMvzTeOZGEqUgawrNYbbZgHwJqd/fkk4SBvDR1AAAA
- Case: PSBT With
PSBT_IN_TAP_KEY_SIGsignature that is too longBytes in Hex:
<70736274ff010071020000000127744ababf3027fe0d6cf23a96eee2efb188ef52301954585883e69b6624b2420000000000ffffffff02787c01000000000016001483a7e34bd99ff03a4962ef8a1a101bb295461ece606b042a010000001600147ac369df1b20e033d6116623957b0ac49f3c52e8000000000001012b00f2052a010000002251205a2c2cf5b52cf31f83ad2e8da63ff03183ecd8f609c7510ae8a48e03910a0757011342173bb3d36c074afb716fec6307a069a2e450b995f3c82785945ab8df0e24260dcd703b0cbf34de399184a9481ac2b3586db6601f026a77f7e4938481bc34751701aa000000Base64 String:
cHNidP8BAHECAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////Anh8AQAAAAAAFgAUg6fjS9mf8DpJYu+KGhAbspVGHs5gawQqAQAAABYAFHrDad8bIOAz1hFmI5V7CsSfPFLoAAAAAAABASsA8gUqAQAAACJRIFosLPW1LPMfg60ujaY/8DGD7Nj2CcdRCuikjgORCgdXARNCFzuz02wHSvtxb+xjB6BpouRQuZXzyCeFlFq43w4kJg3NcDsMvzTeOZGEqUgawrNYbbZgHwJqd/fkk4SBvDR1FwGqAAAA
- Case: PSBT With
PSBT_IN_TAP_BIP32_DERIVATIONkey that is too long (incorrectly serialized as compressed DER)Bytes in Hex:
<70736274ff010071020000000127744ababf3027fe0d6cf23a96eee2efb188ef52301954585883e69b6624b2420000000000ffffffff02787c01000000000016001483a7e34bd99ff03a4962ef8a1a101bb295461ece606b042a010000001600147ac369df1b20e033d6116623957b0ac49f3c52e8000000000001012b00f2052a010000002251205a2c2cf5b52cf31f83ad2e8da63ff03183ecd8f609c7510ae8a48e03910a0757221602fe349064c98d6e2a853fa3c9b12bd8b304a19c195c60efa7ee2393046d3fa2321900772b2da75600008001000080000000800100000000000000000000Base64 String:
cHNidP8BAHECAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////Anh8AQAAAAAAFgAUg6fjS9mf8DpJYu+KGhAbspVGHs5gawQqAQAAABYAFHrDad8bIOAz1hFmI5V7CsSfPFLoAAAAAAABASsA8gUqAQAAACJRIFosLPW1LPMfg60ujaY/8DGD7Nj2CcdRCuikjgORCgdXIhYC/jSQZMmNbiqFP6PJsSvYswShnBlcYO+n7iOTBG0/ojIZAHcrLadWAACAAQAAgAAAAIABAAAAAAAAAAAAAA==
- Case: PSBT With
PSBT_OUT_TAP_INTERNAL_KEYkey that is too long (incorrectly serialized as compressed DER)Bytes in Hex:
70736274ff01007d020000000127744ababf3027fe0d6cf23a96eee2efb188ef52301954585883e69b6624b2420000000000ffffffff02887b0100000000001600142382871c7e8421a00093f754d91281e675874b9f606b042a010000002251205a2c2cf5b52cf31f83ad2e8da63ff03183ecd8f609c7510ae8a48e03910a0757000000000001012b00f2052a010000002251205a2c2cf5b52cf31f83ad2e8da63ff03183ecd8f609c7510ae8a48e03910a0757000001052102fe349064c98d6e2a853fa3c9b12bd8b304a19c195c60efa7ee2393046d3fa23200Base64 String:
cHNidP8BAH0CAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////Aoh7AQAAAAAAFgAUI4KHHH6EIaAAk/dU2RKB5nWHS59gawQqAQAAACJRIFosLPW1LPMfg60ujaY/8DGD7Nj2CcdRCuikjgORCgdXAAAAAAABASsA8gUqAQAAACJRIFosLPW1LPMfg60ujaY/8DGD7Nj2CcdRCuikjgORCgdXAAABBSEC/jSQZMmNbiqFP6PJsSvYswShnBlcYO+n7iOTBG0/ojIA
- Case: PSBT With
PSBT_OUT_TAP_BIP32_DERIVATIONkey that is too long (incorrectly serialized as compressed DER)Bytes in Hex:
70736274ff01007d020000000127744ababf3027fe0d6cf23a96eee2efb188ef52301954585883e69b6624b2420000000000ffffffff02887b0100000000001600142382871c7e8421a00093f754d91281e675874b9f606b042a010000002251205a2c2cf5b52cf31f83ad2e8da63ff03183ecd8f609c7510ae8a48e03910a0757000000000001012b00f2052a010000002251205a2c2cf5b52cf31f83ad2e8da63ff03183ecd8f609c7510ae8a48e03910a07570000220702fe349064c98d6e2a853fa3c9b12bd8b304a19c195c60efa7ee2393046d3fa2321900772b2da7560000800100008000000080010000000000000000Base64 String:
cHNidP8BAH0CAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////Aoh7AQAAAAAAFgAUI4KHHH6EIaAAk/dU2RKB5nWHS59gawQqAQAAACJRIFosLPW1LPMfg60ujaY/8DGD7Nj2CcdRCuikjgORCgdXAAAAAAABASsA8gUqAQAAACJRIFosLPW1LPMfg60ujaY/8DGD7Nj2CcdRCuikjgORCgdXAAAiBwL+NJBkyY1uKoU/o8mxK9izBKGcGVxg76fuI5MEbT+iMhkAdystp1YAAIABAACAAAAAgAEAAAAAAAAAAA==
- Case: PSBT With
PSBT_IN_TAP_SCRIPT_SIGkey that is too long (incorrectly serialized as compressed DER)Bytes in Hex:
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 String:
cHNidP8BAF4CAAAAAZvUh2UjC/mnLmYgAflyVW5U8Mb5f+tWvLVgDYF/aZUmAQAAAAD/////AUjmBSoBAAAAIlEgAw2k/OT32yjCyylRYx4ANxOFZZf+ljiCy1AOaBEsymMAAAAAAAEBKwDyBSoBAAAAIlEgwiR++/2SrEf29AuNQtFpF1oZ+p+hDkol1/NetN2FtpJCFAIssTrGgkjegGqmo2Wc88A+toIdCcgRSk6Gj+vehlu20s2XDhX1P8DIL5UP1WD/qRm3YXK+AXNoqJkTrwdPQAsJQIl1aqNznMxonsD886NgvjLMC1mxbpOh6LtGBXJrLKej/3BsQXZkljKyzGjh+RK4pXjjcZzncQiFx6lm9JvNQ8sAAA==
- Case: PSBT With
PSBT_IN_TAP_SCRIPT_SIGsignature that is too longBytes in Hex:
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 String:
cHNidP8BAF4CAAAAAZvUh2UjC/mnLmYgAflyVW5U8Mb5f+tWvLVgDYF/aZUmAQAAAAD/////AUjmBSoBAAAAIlEgAw2k/OT32yjCyylRYx4ANxOFZZf+ljiCy1AOaBEsymMAAAAAAAEBKwDyBSoBAAAAIlEgwiR++/2SrEf29AuNQtFpF1oZ+p+hDkol1/NetN2FtpJBFCyxOsaCSN6AaqajZZzzwD62gh0JyBFKToaP696GW7bSzZcOFfU/wMgvlQ/VYP+pGbdhcr4Bc2iomROvB09ACwlCiXVqo3OczGiewPzzo2C+MswLWbFuk6Hou0YFcmssp6P/cGxBdmSWMrLMaOH5ErileONxnOdxCIXHqWb0m81DywEBAAA=
- Case: PSBT With
PSBT_IN_TAP_SCRIPT_SIGsignature that is too shortBytes in Hex:
70736274ff01005e02000000019bd48765230bf9a72e662001f972556e54f0c6f97feb56bcb5600d817f6995260100000000ffffffff0148e6052a01000000225120030da4fce4f7db28c2cb2951631e003713856597fe963882cb500e68112cca63000000000001012b00f2052a01000000225120c2247efbfd92ac47f6f40b8d42d169175a19fa9fa10e4a25d7f35eb4dd85b69241142cb13ac68248de806aa6a3659cf3c03eb6821d09c8114a4e868febde865bb6d2cd970e15f53fc0c82f950fd560ffa919b76172be017368a89913af074f400b093f89756aa3739ccc689ec0fcf3a360be32cc0b59b16e93a1e8bb4605726b2ca7a3ff706c4176649632b2cc68e1f912b8a578e3719ce7710885c7a966f49bcd430000Base64 String:
cHNidP8BAF4CAAAAAZvUh2UjC/mnLmYgAflyVW5U8Mb5f+tWvLVgDYF/aZUmAQAAAAD/////AUjmBSoBAAAAIlEgAw2k/OT32yjCyylRYx4ANxOFZZf+ljiCy1AOaBEsymMAAAAAAAEBKwDyBSoBAAAAIlEgwiR++/2SrEf29AuNQtFpF1oZ+p+hDkol1/NetN2FtpJBFCyxOsaCSN6AaqajZZzzwD62gh0JyBFKToaP696GW7bSzZcOFfU/wMgvlQ/VYP+pGbdhcr4Bc2iomROvB09ACwk/iXVqo3OczGiewPzzo2C+MswLWbFuk6Hou0YFcmssp6P/cGxBdmSWMrLMaOH5ErileONxnOdxCIXHqWb0m81DAAA=
- Case: PSBT With
PSBT_IN_TAP_LEAF_SCRIPTControl block that is too longBytes in Hex:
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 String:
cHNidP8BAF4CAAAAAZvUh2UjC/mnLmYgAflyVW5U8Mb5f+tWvLVgDYF/aZUmAQAAAAD/////AUjmBSoBAAAAIlEgAw2k/OT32yjCyylRYx4ANxOFZZf+ljiCy1AOaBEsymMAAAAAAAEBKwDyBSoBAAAAIlEgwiR++/2SrEf29AuNQtFpF1oZ+p+hDkol1/NetN2FtpJjFcFQkpt0waBJVLeLS2A16XpeB4paDyjsltVHv+6azoA6wG99YgWelJehpKJnVp2YdtpgEBr/OONSm5uTnOf5GulwEV8uSQr3zEXE94UR82BXzlxaXFYyWin7RN/CA/NW4fgAIyAssTrGgkjegGqmo2Wc88A+toIdCcgRSk6Gj+vehlu20qzAAAA=
- Case: PSBT With
PSBT_IN_TAP_LEAF_SCRIPTControl block that is too shortBytes in Hex:
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 String:
cHNidP8BAF4CAAAAAZvUh2UjC/mnLmYgAflyVW5U8Mb5f+tWvLVgDYF/aZUmAQAAAAD/////AUjmBSoBAAAAIlEgAw2k/OT32yjCyylRYx4ANxOFZZf+ljiCy1AOaBEsymMAAAAAAAEBKwDyBSoBAAAAIlEgwiR++/2SrEf29AuNQtFpF1oZ+p+hDkol1/NetN2FtpJhFcFQkpt0waBJVLeLS2A16XpeB4paDyjsltVHv+6azoA6wG99YgWelJehpKJnVp2YdtpgEBr/OONSm5uTnOf5GulwEV8uSQr3zEXE94UR82BXzlxaXFYyWin7RN/CA/NW4SMgLLE6xoJI3oBqpqNlnPPAPraCHQnIEUpOho/r3oZbttKswAAA
The following are valid PSBTs:
- Case: PSBT with one P2TR key only input with internal key and its derivation path
Bytes in Hex:
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 String:
cHNidP8BAFICAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////AUjmBSoBAAAAFgAUdo4e60z0IIZgM/gKzv8PlyB0SWkAAAAAAAEBKwDyBSoBAAAAIlEgWiws9bUs8x+DrS6Npj/wMYPs2PYJx1EK6KSOA5EKB1chFv40kGTJjW4qhT+jybEr2LMEoZwZXGDvp+4jkwRtP6IyGQB3Ky2nVgAAgAEAAIAAAACAAQAAAAAAAAABFyD+NJBkyY1uKoU/o8mxK9izBKGcGVxg76fuI5MEbT+iMgAiAgNrdyptt02HU8mKgnlY3mx4qzMSEJ830+AwRIQkLs5z2Bh3Ky2nVAAAgAEAAIAAAACAAAAAAAAAAAAA
- Case: PSBT with one P2TR key only input with internal key, its derivation path, and signature
Bytes in Hex:
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 String:
cHNidP8BAFICAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////AUjmBSoBAAAAFgAUdo4e60z0IIZgM/gKzv8PlyB0SWkAAAAAAAEBKwDyBSoBAAAAIlEgWiws9bUs8x+DrS6Npj/wMYPs2PYJx1EK6KSOA5EKB1cBE0C7U+yRe62dkGrxuocYHEi4as5aritTYFpyXKdGJWMUdvxvW67a9PLuD0d/NvWPOXDVuCc7fkl7l68uPxJcl680IRb+NJBkyY1uKoU/o8mxK9izBKGcGVxg76fuI5MEbT+iMhkAdystp1YAAIABAACAAAAAgAEAAAAAAAAAARcg/jSQZMmNbiqFP6PJsSvYswShnBlcYO+n7iOTBG0/ojIAIgIDa3cqbbdNh1PJioJ5WN5seKszEhCfN9PgMESEJC7Oc9gYdystp1QAAIABAACAAAAAgAAAAAAAAAAAAA==
- Case: PSBT with one P2TR key only output with internal key and its derivation path
Bytes in Hex:
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 String:
cHNidP8BAF4CAAAAASd0Srq/MCf+DWzyOpbu4u+xiO9SMBlUWFiD5ptmJLJCAAAAAAD/////AUjmBSoBAAAAIlEgg2mORYxmZOFZXXXaJZfeHiLul9eY5wbEwKS1qYI810MAAAAAAAEBKwDyBSoBAAAAIlEgWiws9bUs8x+DrS6Npj/wMYPs2PYJx1EK6KSOA5EKB1chFv40kGTJjW4qhT+jybEr2LMEoZwZXGDvp+4jkwRtP6IyGQB3Ky2nVgAAgAEAAIAAAACAAQAAAAAAAAABFyD+NJBkyY1uKoU/o8mxK9izBKGcGVxg76fuI5MEbT+iMgABBSARJNp67JLM0GyVRWJkf0N7E4uVchqEvivyJ2u92rPmcSEHESTaeuySzNBslUViZH9DexOLlXIahL4r8idrvdqz5nEZAHcrLadWAACAAQAAgAAAAIAAAAAABQAAAAA=
- Case: PSBT with one P2TR script path only input with dummy internal key, scripts, derivation paths for keys in the scripts, and merkle root
Bytes in Hex:
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 String:
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- Case: PSBT with one P2TR script path only output with dummy internal key, taproot tree, and script key derivation paths
Bytes in Hex:
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 String:
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
- Case: PSBT with one P2TR script path only input with dummy internal key, scripts, script key derivation paths, merkle root, and script path signatures
Bytes in Hex:
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 String:
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
Rationale
Why is there no key data for
PSBT_IN_TAP_KEY_SIGThe signature in a key path spend corresponds directly with the pubkey provided in the output script. Thus it is not necessary to provide any metadata that attaches the key path spend signature to a particular pubkey.Why is the internal key provided?The internal key is not necessarily the same key as in the Taproot output script. BIP 341 recommends tweaking the key with the hash of itself. It may be necessary for signers to know what the internal key actually is so that they are able to determine whether an input can be signed by it.
Reference implementation
The reference implementation of the PSBT format is available at https://github.com/achow101/bitcoin/tree/taproot-psbt.
Acknowledgements
TBD