Hi,

I didn’t read the referenced source, but I’m curious why deterministic is so 
heavily emphasized. Seems like there’s two cases:

1) You transmit the signed/hashed data with signature/hash in which case you 
don’t need determinism.
2) The sender and receiver independently do the CBOR encoding of what is 
signed/hashed, in which case you do need determinism.

The encoding of Sig_structure in COSE is an example of 2), and the payload of a 
COSE_Sign is an example of 1). Are you doing a lot of 2) here?

Also, what is the limitation with COSE? Seems like you could use a detached 
signature where the payload is independently and deterministically computed 
rather than transmitted.

Is there a further detailed definition of determinism, such as what to do with 
floats?

LL



> On Feb 15, 2023, at 10:12 PM, Anders Rundgren <[email protected]> 
> wrote:
> 
> Deterministic CBOR will as I predicted go where JOSE and COSE did not.
> What's missing (IMO) is well-defined subset where for example map keys would 
> either be tstr or integer.
> Anders
> 
> 
> -------- Forwarded Message --------
> Subject:      New deterministic CBOR Libraries (Rust & Swift) from Blockchain 
> Commons
> Resent-Date:  Thu, 16 Feb 2023 01:00:25 +0000
> Resent-From:  [email protected] <mailto:[email protected]>
> Date: Wed, 15 Feb 2023 16:59:31 -0800
> From: Christopher Allen <[email protected]> 
> <mailto:[email protected]>
> To:   Credentials Community Group <[email protected]> 
> <mailto:[email protected]>, W3C Verifiable Credentials WG 
> <[email protected]> <mailto:[email protected]>
> CC:   Wolf McNally <[email protected]> <mailto:[email protected]>, 
> Shannon Appelcline <[email protected]> 
> <mailto:[email protected]>
> 
> Since I know that many projects in the broader Credentials Community already 
> use CBOR, I'd like to announce Blockchain Commons' release of dCBOR libraries 
> for Rust and Swift. In particular, these two languages demonstrate our 
> support of use cases for dCBOR for mobile in Android and iOS:
> dCBOR Codec for Rust: https://github.com/BlockchainCommons/bc-dcbor-rust 
> <https://github.com/BlockchainCommons/bc-dcbor-rust>
> dCBOR Codec for Swift: https://github.com/BlockchainCommons/BCSwiftDCBOR 
> <https://github.com/BlockchainCommons/BCSwiftDCBOR>We've also produced a CLI 
> app using our Rust library, which can be used to test parsing and validation:
> dCBOR CLI: https://github.com/BlockchainCommons/dcbor-cli 
> <https://github.com/BlockchainCommons/dcbor-cli>We focused on the 
> deterministic flavor of CBOR per §4.2 of RFC-8949  
> <https://www.rfc-editor.org/rfc/rfc8949.html#name-deterministically-encoded-c>because
>  of our specific need to produce deterministically repeatable hashes in the 
> Merkle Tree underlying our Gordian Envelope 
> <https://www.blockchaincommons.com/introduction/Envelope-Intro/> data format. 
> We suspect that there will be others with similar needs and hope these dCBOR 
> libraries will prove useful for other specs & standards using CBOR!
> 
> I'd love to get any advice, comments, or thoughts you have on our dCBOR 
> libraries, as well as any requirements that the libraries may need to meet. 
> I'd also appreciate to get any CCG-related CBOR test examples that we can use 
> in documents and examples, such as mDL and COSE tests.
> 
> I'm also happy to discuss why we picked CBOR 
> <https://www.blockchaincommons.com/introduction/Why-CBOR/> as a data format 
> and why dCBOR is particularly advantageous, either here or in our discussion 
> forums at GitHub <https://github.com/orgs/BlockchainCommons/discussions/184>.
> 
> Thanks!
> 
> -- Christopher Allen
>    Blockchain Commons
> _______________________________________________
> COSE mailing list
> [email protected]
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