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Add hash algorithm for authorizing data.

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Kris Nuttycombe 2021-01-07 12:27:03 -07:00
parent 71e90991e8
commit 381b67a650
1 changed files with 90 additions and 14 deletions
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@ -97,10 +97,24 @@ initial requirement that all transactions be non-malleable.
Specification
=============
-------
Digests
-------
All digests are personalized BLAKE2b-256 hashes. In cases where no elements are
available for hashing (for example, if there are no TZE inputs) the resulting hash
will be over just the personalization string, providing domain separation even for
empty data fields.
TxId Digest
===========
A new transaction digest algorithm is defined that constructs the identifier for
a transaction from a tree of hashes. The overall structure of the hash is as follows:
top_digest
txid_digest
├── header_digest
├── transparent_digest
│   ├── prevouts_digest
@ -124,19 +138,7 @@ Each node written as ``snake_case`` in this tree is a BLAKE2b-256 hash of its
children, initialized with a personalization string specific to that branch
of the tree. Nodes that are not themselves digests are written in ``camelCase``.
-------
Digests
-------
All digests are personalized BLAKE2b-256 hashes. In cases where no elements are
available for hashing (for example, if there are no TZE inputs) the resulting hash
will be over just the personalization string, providing domain separation even for
empty data fields.
Digest definitions
==================
``top_digest``
``txid_digest``
--------------
A BLAKE2b-256 hash of the following values ::
@ -341,11 +343,85 @@ The personalization field of this hash is set to::
"ZTxIdSOutN__Hash"
Witness Digest
==============
A new transaction digest algorithm is defined that constructs a digest which commits
to the authorizing data of a transaction from a tree of BLAKE2b-256 hashes.
The overall structure of the hash is as follows:
auth_digest
├── transparent_scripts_digest
├── tze_witnesses_digest
├── sprout_sigs_digest
└── sapling_sigs_digest
Each node written as ``snake_case`` in this tree is a BLAKE2b-256 hash of authorizing
data of the transaction.
``auth_digest``
--------------
A BLAKE2b-256 hash of the following values ::
* ``transparent_scripts_digest`` (32-byte hash output)
* ``tze_witnesses_digest (32-byte hash output)
* ``sprout_sigs_digest (32-byte hash output)
* ``sapling_sigs_digest (32-byte hash output)
The personalization field of this hash is set to::
"ZTxAuth_____Hash"
1: ``transparent_scripts_digest``
`````````````````````````````````
A BLAKE2b-256 hash of the *transaction serialized form* of the Bitcoin script associated
with each transparent input belonging to the transaction.
The personalization field of this hash is set to::
"ZTxAuthTransHash"
2: ``tze_witnesses_digest``
```````````````````````````
A BLAKE2b-256 hash of the *transaction serialized form* of the witness data associated
with each TZE input belonging to the transaction.
The personalization field of this hash is set to::
"ZTxAuthTZE__Hash"
3: ``sprout_sigs_digest``
```````````````````````````
A BLAKE2b-256 hash of the *transaction serialized form* of the joinsplit signature
belonging to the transaction.
The personalization field of this hash is set to::
"ZTxAuthSprouHash"
3: ``sapling_sigs_digest``
```````````````````````````
A BLAKE2b-256 hash of the *transaction serialized form* of the sapling signature
of each Sapling spend description belonging to the transaction, followed by the
*transaction serialized form* of the binding signature.
The personalization field of this hash is set to::
"ZTxAuthSapliHash"
--------------------
Block Header Changes
--------------------
// TODO: Need @str4d's help here.
========================
Reference implementation
========================
- https://github.com/zcash/librustzcash/pull/319/files
==========
References
==========