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ZIP 316: Update Sapling and transparent viewing key encodings. 

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
This commit is contained in:
Daira Hopwood 2021-12-08 00:24:35 +00:00
parent 026977744c
commit 208d9b39c1
1 changed files with 13 additions and 8 deletions
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zip-0316.rst
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@ -392,10 +392,12 @@ The following FVK or IVK Encodings are used in place of the
is the raw encoding of the Orchard Full Viewing Key or Orchard Incoming
Viewing Key respectively.
* A Sapling FVK Encoding, with Typecode :math:`\mathtt{0x02},` is
the encoding of a Sapling Extended Full Viewing Key defined in
[#zip-0032-sapling-extfvk]_. This SHOULD be an Extended Full Viewing
Key at the Account level of the ZIP 32 hierarchy.
* A Sapling FVK Encoding, with Typecode :math:`\mathtt{0x02},` is the
encoding of :math:`(\mathsf{ak}, \mathsf{nk}, \mathsf{ovk}, \mathsf{dk})`
given by :math:`\mathsf{EncodeExtFVKParts}(\mathsf{ak}, \mathsf{nk}, \mathsf{ovk}, \mathsf{dk})`,
where :math:`\mathsf{EncodeExtFVKParts}` is defined in [#zip-0032-sapling-helper-functions]_.
This SHOULD be derived from the Extended Full Viewing Key at the Account
level of the ZIP 32 hierarchy.
* A Sapling IVK Encoding, also with Typecode :math:`\mathtt{0x02},`
is an encoding of :math:`(\mathsf{dk}, \mathsf{ivk})` given by
@ -408,10 +410,12 @@ The following FVK or IVK Encodings are used in place of the
treated as unrecognized by Consumers.
* For Transparent P2PKH Addresses that are derived according to BIP 32
[#bip-0032]_ and BIP 44 [#bip-0044]_, the FVK and IVK Encodings
have Typecode :math:`\mathtt{0x00}.` Both of these encodings are the
serialization of an extended public key, defined in the section
“Serialization format” of BIP 32 [#bip-0032-serialization-format]_.
[#bip-0032]_ and BIP 44 [#bip-0044]_, the FVK and IVK Encodings have
Typecode :math:`\mathtt{0x00}.` Both of these are encodings of the
chain code and public key :math:`(\mathsf{c}, \mathsf{pk})` given by
:math:`\mathsf{c}\,||\,\mathsf{ser_P}(\mathsf{pk})`. (This is the
same as the last 65 bytes of the extended public key format defined
in section “Serialization format” of BIP 32 [#bip-0032-serialization-format]_.)
However, the FVK uses the key at the Account level, i.e. at path
:math:`m / 44' / coin\_type' / account'`, while the IVK uses its
non-change child key at path :math:`m / 44' / coin\_type' / account' / 0`.
@ -799,6 +803,7 @@ References
.. [#protocol-orchardinviewingkeyencoding] `Zcash Protocol Specification, Version 2020.2.16. Section 5.6.4.3: Orchard Raw Incoming Viewing Keys <protocol/protocol.pdf#orchardinviewingkeyencoding>`_
.. [#protocol-orchardfullviewingkeyencoding] `Zcash Protocol Specification, Version 2020.2.16. Section 5.6.4.4: Orchard Raw Full Viewing Keys <protocol/protocol.pdf#orchardfullviewingkeyencoding>`_
.. [#zip-0000] `ZIP 0: ZIP Process <zip-0000.rst>`_
.. [#zip-0032-sapling-helper-functions] `ZIP 32: Shielded Hierarchical Deterministic Wallets — Sapling helper functions <zip-0032#sapling-helper-functions>`_
.. [#zip-0032-sapling-extfvk] `ZIP 32: Shielded Hierarchical Deterministic Wallets — Sapling extended full viewing keys <zip-0032#sapling-extended-full-viewing-keys>`_
.. [#zip-0032-sapling-diversifier-derivation] `ZIP 32: Shielded Hierarchical Deterministic Wallets — Sapling diversifier derivation <zip-0032#sapling-diversifier-derivation>`_
.. [#zip-0032-orchard-child-key-derivation] `ZIP 32: Shielded Hierarchical Deterministic Wallets — Orchard child key derivation <zip-0032#orchard-child-key-derivation>`_