feat(docs): Catalyst vote v2

docs/src/architecture/08_concepts/catalyst_voting/crypto.md

@@ -65,7 +65,6 @@ Before any voting will start an initial setup procedure should be performed.
 * As most of the crypto algorithms are group dependent
   (more about this you can read in [appendix A](#a-group-definition)),
   it is needed to specifically define which cryptographically secure group would be used.
-* Define a hash function which will be used by the underlying crypto algorithms.
 * Define a commitment key $ck$,
   which will be used during the voter proof generation and verification procedures.
 
@@ -502,7 +501,7 @@ To compute it, prover needs to perform the next steps:
     * $A_l = g^{i_l * \beta_l} \circ ck^{\delta_l}, A_l \in \mathbb{G}$.
 5. Calculate a first verifier challenge
   $ch_1 = H(ck, pk, \{c_j\}, \{I_l\}, \{B_l\}, \{A_l\})$,
-  where $H$ is a hash function,
+  where $H$ is [BLAKE2b-512] hash function,
   $j \in [0, \ldots, N-1]$
   and $l \in [0, \ldots, log_2(N)-1]$.
 6. For $j \in [0, \ldots, N-1]$ calculate polynomials
@@ -518,7 +517,7 @@ To compute it, prover needs to perform the next steps:
   and $p_{j,l}$ - corresponding coefficients of the polynomial $p_j(x)$ calculated on step `7`.
 9. Calculate a second verifier challenge
   $ch_2 = H(ch_1, \{D_l\})$,
-  where $H$ is a hash function
+  where $H$ is [BLAKE2b-512] hash function
   and $l \in [0, \ldots, log_2(N)-1]$.
 10. For $l \in [0, \ldots, log_2(N)-1]$ calculate:
     * $z_l = i_l * ch_2 + \beta_l, z_l \in \mathbb{Z}_q$.
@@ -558,12 +557,12 @@ verifier needs to perform the next steps:
   So the resulted $\mathbf{c} = (c_1, \ldots, c_M, \{c_j\})$.
 2. Calculate the first verifier challenge
   $ch_1 = H(ck, pk, \{c_j\}, \{I_l\}, \{B_l\}, \{A_l\})$,
-  where $H$ is a hash function,
+  where $H$ is [BLAKE2b-512] hash function,
   $j \in [0, \ldots, N-1]$
   and $l \in [0, \ldots, log_2(N)-1]$.
 3. Calculate a second verifier challenge
   $ch_2 = H(ch_1, \{D_l\})$,
-  where $H$ is a hash function
+  where $H$ is [BLAKE2b-512] hash function
   and $l \in [0, \ldots, log_2(N)-1]$.
 4. For $l \in [0, \ldots, log_2(N)-1]$ verify that the following statements are `true`,
   where $g$ is the group generator:
@@ -683,3 +682,4 @@ If step `6` returns `true` so the final result is `true` otherwise return `false
 [treasury_system_paper]: https://eprint.iacr.org/2018/435.pdf
 [treasury_system_spec]: https://github.com/input-output-hk/treasury-crypto/blob/master/docs/voting_protocol_spec/Treasury_voting_protocol_spec.pdf
 [crypto_book]: https://gnanavelrec.wordpress.com/wp-content/uploads/2019/06/2.understanding-cryptography-by-christof-paar-.pdf
+[BLAKE2b-512]: https://www.blake2.net/blake2.pdf

docs/src/architecture/08_concepts/catalyst_voting/transaction.md

@@ -1,8 +1,8 @@
-# Transaction
+# Transactions
 
 ---
 
-Title: Voting Transaction
+Title: Voting Transactions
 
 Status: Proposed
 
@@ -87,8 +87,7 @@ the following properties are used:
 
 1. Each proposal, defined by the "Vote plan id" and "Proposal index", defines a number of possible options.
 2. [ristretto255] as a backend cryptographic group.
-3. [BLAKE2b-512] hash function.
-4. A commitment key $ck$ defined as a [BLAKE2b-512] hash of the "Vote plan id" bytes.
+3. A commitment key $ck$ defined as a [BLAKE2b-512] hash of the "Vote plan id" bytes.
 
 #### Transaction signing (witness generation)
 
@@ -115,7 +114,56 @@ Expected witness (includes signature)
 
 <!-- markdownlint-disable code-block-style -->
 ```hex
-    0200000000e6c8aa48925e37fdab75db13aca7c4f39068e12eeb3af8fd1f342005cae5ab9a1ef5344fab2374e9436a67f57041899693d333610dfe785d329988736797950d
+0200000000e6c8aa48925e37fdab75db13aca7c4f39068e12eeb3af8fd1f342005cae5ab9a1ef5344fab2374e9436a67f57041899693d333610dfe785d329988736797950d
+```
+<!-- markdownlint-enable code-block-style -->
+
+### v2
+
+<!-- markdownlint-disable max-one-sentence-per-line code-block-style -->
+??? note "V2 vote transaction definition: `tx_v2.cddl`"
+
+    ```CDDL
+    {{ include_file('src/architecture/08_concepts/catalyst_voting/tx_v2.cddl', indent=4) }}
+    ```
+<!-- markdownlint-enable max-one-sentence-per-line code-block-style -->
+
+`event` - a set of different identifiers which is uniquely define a particular voting event.
+
+Vote:
+
+* `choices` - a collection of voter choices for the proposal.
+* `proof` - a voter proof, could be `null`.
+* `prop_id` - a proposal id for which `choice` is made, could be `null`.
+  For that case where for the voting event defined only **one** proposal,
+  so it's redundant to provide an additional identifier for the proposal,
+  so it could be placed `null`.
+
+`voters_data` - an any additional voter's specific data.
+
+#### Transaction signing
+
+[COSE] is used to define a transaction's signature structure.
+[COSE] is a flexible security protocol that supports various types of security messages.
+However, only `COSE Signed Data Object` or `COSE_Sign` type is used.
+
+The following header must be included in the [COSE] signature.
+
+`protected`:
+
+* `content type`: `application/cbor`
+  (this parameter is used to indicate the content type of the data in the payload or ciphertext fields).
+
+Any other headers as `alg`, `kid` etc. could be specified of any kind and not defined by this spec.
+
+##### Signature payload
+
+As mentioned earlier, the content type of the [COSE] signature payload is `application/cbor`.
+In particular it must be a [CBOR] encoded [BLAKE2b-256] hash bytes:
+
+<!-- markdownlint-disable code-block-style -->
+```CDDL
+{{ include_file('src/architecture/08_concepts/catalyst_voting/tx_v2_cose_payload.cddl') }}
 ```
 <!-- markdownlint-enable code-block-style -->
 
@@ -131,6 +179,8 @@ Expected witness (includes signature)
 
 <!-- OPTIONAL SECTIONS: see CIP-0001 > Document > Structure table -->
 
-[BLAKE2b-256]: https://www.blake2.net/blake2.pdf\
-[BLAKE2b-512]: https://www.blake2.net/blake2.pdf\
+[BLAKE2b-256]: https://www.blake2.net/blake2.pdf
+[BLAKE2b-512]: https://www.blake2.net/blake2.pdf
 [ristretto255]: https://ristretto.group
+[COSE]: https://datatracker.ietf.org/doc/rfc9052/
+[CBOR]: https://datatracker.ietf.org/doc/rfc8949/

docs/src/architecture/08_concepts/catalyst_voting/tx_v2.cddl

@@ -0,0 +1,26 @@
+vote_tx = [
+    vote_tx_body,
+    signature
+]
+
+vote_tx_body = [
+    vote_type: UUID ; e.g. Public or Private vote
+    event,
+    votes,
+    voters_data: encoded_cbor
+]
+
+event = { * event_key => any }
+event_key = int / text
+
+votes = [+ vote]
+vote = [
+    choices: encoded-cbor,
+    proof: encoded-cbor / null,
+    prop_id: encoded-cbor / null,
+]
+choices = [+ choice]
+choice = encoded-cbor
+
+UUID = #6.37(bytes) ; UUID type
+signature = #6.98(COSE_Sign) ; COSE signature

docs/src/architecture/08_concepts/catalyst_voting/tx_v2_cose_payload.cddl

@@ -0,0 +1,2 @@
+cose_payload = blake2b-256
+blake2b-256 = #6.32782(bytes .size 32) ; Blake2b-256 hash bytes