serai/crypto/transcript/README.md

# Flexible Transcript

Flexible Transcript is a crate offering:
- `Transcript`, a trait offering functions transcripts should implement.
- `DigestTranscript`, a competent transcript format instantiated against a
provided hash function.
- `MerlinTranscript`, a wrapper of `merlin` into the trait (available via the
`merlin` feature).
- `RecommendedTranscript`, a transcript recommended for usage in applications.
  Currently, this is `DigestTranscript<Blake2b512>` (available via the
  `recommended` feature).

The trait was created while working on an IETF draft which defined an incredibly
simple transcript format. Extensions of the protocol would quickly require a
more competent format, yet implementing the one specified was mandatory to meet
the specification. Accordingly, the library implementing the draft defined an
`IetfTranscript`, dropping labels and not allowing successive challenges, yet
thanks to the trait, allowed protocols building on top to provide their own
transcript format as needed.

`DigestTranscript` takes in any hash function implementing `Digest`, offering a
secure transcript format around it. All items are prefixed by a flag, denoting
their type, and their length.

`MerlinTranscript` was used to justify the API, and if any issues existed with
`DigestTranscript`, enable a fallback. It was also meant as a way to be
compatible with existing Rust projects using `merlin`.

This library was
[audited by Cypher Stack in March 2023](https://github.com/serai-dex/serai/raw/e1bb2c191b7123fd260d008e31656d090d559d21/audits/Cypher%20Stack%20crypto%20March%202023/Audit.pdf),
culminating in commit
[669d2dbffc1dafb82a09d9419ea182667115df06](https://github.com/serai-dex/serai/tree/669d2dbffc1dafb82a09d9419ea182667115df06).
Any subsequent changes have not undergone auditing.

This library is usable under no_std.
Rename transcript-trait to flexible-transcript It offers the trait for flexibility, yet it also offers an incredibly competent (and logical) transcript format, along with a Merlin wrapper. 2022-06-27 13:02:21 +00:00			`# Flexible Transcript`
Prepare transcript for publishing 2022-06-19 10:35:15 +00:00
Rename transcript-trait to flexible-transcript It offers the trait for flexibility, yet it also offers an incredibly competent (and logical) transcript format, along with a Merlin wrapper. 2022-06-27 13:02:21 +00:00			`Flexible Transcript is a crate offering:`
			- `Transcript`, a trait offering functions transcripts should implement.
			- `DigestTranscript`, a competent transcript format instantiated against a
			`provided hash function.`
			- `MerlinTranscript`, a wrapper of `merlin` into the trait (available via the
			`merlin` feature).
Document the transcript library 2022-07-09 04:37:39 +00:00			- `RecommendedTranscript`, a transcript recommended for usage in applications.
			Currently, this is `DigestTranscript<Blake2b512>` (available via the
			`recommended` feature).
Rename transcript-trait to flexible-transcript It offers the trait for flexibility, yet it also offers an incredibly competent (and logical) transcript format, along with a Merlin wrapper. 2022-06-27 13:02:21 +00:00
			`The trait was created while working on an IETF draft which defined an incredibly`
			`simple transcript format. Extensions of the protocol would quickly require a`
			`more competent format, yet implementing the one specified was mandatory to meet`
			`the specification. Accordingly, the library implementing the draft defined an`
			`IetfTranscript`, dropping labels and not allowing successive challenges, yet
			`thanks to the trait, allowed protocols building on top to provide their own`
			`transcript format as needed.`

			`DigestTranscript` takes in any hash function implementing `Digest`, offering a
			`secure transcript format around it. All items are prefixed by a flag, denoting`
			`their type, and their length.`

			`MerlinTranscript` was used to justify the API, and if any issues existed with
			`DigestTranscript`, enable a fallback. It was also meant as a way to be
			compatible with existing Rust projects using `merlin`.
Document crypto crates with audit notices 2023-03-16 22:46:48 +00:00
			`This library was`
Fully document crypto/ 2023-03-21 00:10:00 +00:00			`[audited by Cypher Stack in March 2023](https://github.com/serai-dex/serai/raw/e1bb2c191b7123fd260d008e31656d090d559d21/audits/Cypher%20Stack%20crypto%20March%202023/Audit.pdf),`
			`culminating in commit`
			`[669d2dbffc1dafb82a09d9419ea182667115df06](https://github.com/serai-dex/serai/tree/669d2dbffc1dafb82a09d9419ea182667115df06).`
			`Any subsequent changes have not undergone auditing.`
Add no_std support to transcript, dalek-ff-group, ed448, ciphersuite, multiexp, schnorr, and monero-generators transcript, dalek-ff-group, ed449, and ciphersuite are all usable with no_std alone. The rest additionally require alloc. Part of #279. 2023-04-22 08:38:47 +00:00
			`This library is usable under no_std.`