2022-06-27 13:02:21 +00:00
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# Flexible Transcript
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2022-06-19 10:35:15 +00:00
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2022-06-27 13:02:21 +00:00
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Flexible Transcript is a crate offering:
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- `Transcript`, a trait offering functions transcripts should implement.
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- `DigestTranscript`, a competent transcript format instantiated against a
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provided hash function.
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- `MerlinTranscript`, a wrapper of `merlin` into the trait (available via the
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`merlin` feature).
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2022-07-09 04:37:39 +00:00
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- `RecommendedTranscript`, a transcript recommended for usage in applications.
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Currently, this is `DigestTranscript<Blake2b512>` (available via the
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`recommended` feature).
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2022-06-27 13:02:21 +00:00
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The trait was created while working on an IETF draft which defined an incredibly
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simple transcript format. Extensions of the protocol would quickly require a
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more competent format, yet implementing the one specified was mandatory to meet
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the specification. Accordingly, the library implementing the draft defined an
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`IetfTranscript`, dropping labels and not allowing successive challenges, yet
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thanks to the trait, allowed protocols building on top to provide their own
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transcript format as needed.
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`DigestTranscript` takes in any hash function implementing `Digest`, offering a
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secure transcript format around it. All items are prefixed by a flag, denoting
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their type, and their length.
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`MerlinTranscript` was used to justify the API, and if any issues existed with
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`DigestTranscript`, enable a fallback. It was also meant as a way to be
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compatible with existing Rust projects using `merlin`.
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