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Re: Introducing CBOR-LD...

From: Leonard Rosenthol <lrosenth@adobe.com>
Date: Fri, 24 Jul 2020 13:57:34 +0000
To: Manu Sporny <msporny@digitalbazaar.com>, W3C Credentials CG <public-credentials@w3.org>
Message-ID: <77FE188D-15D5-429B-B01D-4D75DD5FE375@adobe.com>
Manu - I agree that there is a problem to be solved here, and I appreciate the work that you and your team has done to architect one possible approach.

While the use of a pre-defined dictionary approach to improving compression ratios is well established and proven - there is a reason that it isn't used for data that is "long lived" -  versioning (or lack thereof).  There is no way to for a given decoder to know what version of the dictionary was used to compress the data - and (of course) they must match.  In our world where (standard) schemas are being created & edited daily, let alone the existence of custom ones - I just don't see how this will work for the types of data being considered here (eg. VC's)

Accordingly, I don’t see this as a viable option.


On 7/23/20, 9:51 PM, "Manu Sporny" <msporny@digitalbazaar.com> wrote:

    Hi W3C Credentials Community Group,

    This email introduces CBOR-LD, the Concise Binary Object Representation
    for Linked Data.

    CBOR-LD provides a general purpose algorithm to compress JSON-LD
    documents, such as W3C Verifiable Credentials and W3C Decentralized
    Identifier Documents, to a compact binary representation. Using this new
    technology, it is possible to achieve compression ratios north of 300%,
    resulting in new ecosystem capabilities like being able to squeeze a
    digitally signed Verifiable Credential into a relatively small QR Code,
    store 3x as many VCs in a digital wallet, and other gains in storage
    efficiency. The algorithm is generalized and is able to achieve these
    gains for many types of JSON-LD inputs.

    An introductory presentation on CBOR-LD is attached as a PDF. The latest
    copy of the presentation is here:


    There is an implementation of the concepts outlined in the presentation
    above here in Node.js (browser-based version coming soon-ish):


    A very rough specification is forming here:


    This is mostly just a notification of work that is ready for public
    circulation, discussion, and feedback. Digital Bazaar feels pretty
    confident in the direction of the work at this point, but also cautions
    that this is merely a start and there will need to be many more months
    of work put into it to discover bugs, finalize the general algorithm,
    and perform other nascent technology gyrations. We would not recommend
    that anyone implement the technology at this time without reading the
    source implementation above. There are known bugs and this technology
    isn't ready for prime time -- DO NOT use it for production deployments
    unless you really know what you're doing -- expect things to change.

    We will have a public presentation on CBOR-LD in a few weeks and will
    let this group know when and where that is happening. In the meantime,
    questions and feedback via the mailing list and via the appropriate
    Github issue tracker is appreciated.

    W3C CCG Chairs, the intent here is to NOT make this a CCG work item and
    instead send it through the JSON-LD CG/WG. That said, the technology
    could have a significant impact on the work in this community and we
    are, therefore, requesting time to discuss it on a future CCG call (with
    invitations sent to other W3C WGs like JSON-LD, VCWG, DID WG, Web of
    Things WG, etc.). Thoughts?

    -- manu

    Manu Sporny - https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.linkedin.com%2Fin%2Fmanusporny%2F&amp;data=02%7C01%7Clrosenth%40adobe.com%7Cbb5d3dcf7f9649b82ed508d82f74029a%7Cfa7b1b5a7b34438794aed2c178decee1%7C0%7C0%7C637311522622748710&amp;sdata=KGBpg8krx9DDoZ7cyaEUDxlMgOnjFTc%2BtvUmXGQ23ZM%3D&amp;reserved=0
    Founder/CEO - Digital Bazaar, Inc.
    blog: Veres One Decentralized Identifier Blockchain Launches

Received on Friday, 24 July 2020 13:57:54 UTC

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