Re: proofs for fragments of JSON-LD documents

 When you say Linked Data Security Specification are you referring to
https://w3c-ccg.github.io/ld-proofs/

On Tue, Nov 17, 2020 at 6:38 PM Kyle Den Hartog <kyle.denhartog@mattr.global>
wrote:

> I'd think you could either choose to split the Verifiable credentials such
> that they're signing only the data they need to, use multiple proofs as
> defined in the Linked Data Security specification, or if you have a size
> constraint and want to play with some fancy crypto then a BLS aggregate
> signature[1] could be a good option too.
>
> [1]: https://tools.ietf.org/html/draft-irtf-cfrg-bls-signature-04
>
> -Kyle
>
> On Wed, Nov 18, 2020 at 7:57 AM Ryan Grant <w3c@rgrant.org> wrote:
>
>> When a Verifiable Credential use case (which may require one or more
>> Verifiable Credentials, depending on the answer to this question)
>> requires different issuers to sign the matter at hand, what is the
>> appropriate method of presentation?
>>
>>
>>
>> On Sat, Nov 7, 2020 at 7:28 PM Manu Sporny <msporny@digitalbazaar.com>
>> wrote:
>> >
>> > On 11/5/20 10:35 AM, Giuseppe Tropea wrote:
>> > > In other words, would it be desirable to specify a way for the
>> > > algorithms to natively operate on portions of JSON-LD documents vs.
>> > > the whole?
>> >
>> > No, absolutely not -- this is a really dangerous idea, please don't ever
>> > do it. :)
>> >
>> > If you can help it, you never want to digitally sign just a subset of
>> > information. Linked Data Security was designed to avoid this mistake on
>> > purpose.
>> >
>> > The issue with signing subsets of information in an otherwise digitally
>> > signed document is that a significant number of developers then go on to
>> > assume that /everything/ is signed, when it is not.
>> >
>> > Linked Data Security digitally signs everything, both the message and
>> > *all* of the signing parameters. Don't want something signed? Tough, you
>> > can't do it -- because it will lead to security vulnerabilities.
>> >
>> > The correct approach is to verify signatures for all of the pieces of
>> > information you have and then merge everything together (which is one of
>> > the things that Linked Data is designed to do -- easy merging).
>> >
>> > It is possible to create an encapsulating JSON-LD container that isn't
>> > signed, but even then, important that you avoid that if you can.
>> >
>> > Hope that helps. :)
>> >
>> > -- manu
>> >
>> > --
>> > Manu Sporny - https://www.linkedin.com/in/manusporny/
>> > Founder/CEO - Digital Bazaar, Inc.
>> > blog: Veres One Decentralized Identifier Blockchain Launches
>> > https://tinyurl.com/veres-one-launches
>> >
>>
>>
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