Re: New Work Item Proposal: Revocation List 2020

I find this proposal really hard to understand.

- Adrian

On Fri, May 1, 2020 at 6:20 PM Daniel Hardman <daniel.hardman@evernym.com>
wrote:

> How is this privacy-preserving? Can you say some more about that?
>
> On Fri, May 1, 2020 at 3:43 PM Manu Sporny <msporny@digitalbazaar.com>
> wrote:
>
>> Hi all,
>>
>> One of Digital Bazaar's deliverables for the DHS SVIP program was a
>> privacy-preserving Verifiable Credential revocation mechanism that would
>> be implementable and deployable by a large section of the Verifiable
>> Credential implementer ecosystem. We have finished the first end-to-end
>> implementation and testing of the system and feel that it's good enough
>> to release to get feedback from the broader community at this time.
>>
>> At the most basic level, this technology expresses revocation
>> information for all Verifiable Credentials issued by an issuer  as
>> simple binary values. The issuer keeps a bitstring list of all
>> Verifiable Credentials it has issued. Each Cerifiable Credential is
>> associated with a position in the list. If the binary value of the
>> position in the list is 1 (one), the verifiable credential is revoked,
>> if it is 0 (zero) it is not revoked.
>>
>> One of the benefits of using a bitstring is that it is a highly
>> compressible data format since, in the average case, large numbers of
>> credentials will remain unrevoked. This will ensure long sections of
>> bits that are the same value and thus highly compressible using
>> run-length compression techniques such as ZLIB [RFC1950]. The default
>> bitstring size is 16KB (131,072 entries), and when only a handful of
>> verifiable credentials are revoked, the compressed bitstring size is
>> reduced down to a few hundred bytes.
>>
>> Another benefit of using a bitstring is that it enables large numbers of
>> verifiable credential revocation statuses to be placed in the same list.
>> This specification utilizes a minimum bitstring length of 131,072
>> (16KB). This population size ensures an adequate amount of herd privacy
>> in the average case. If better herd privacy is required, the bitstring
>> can be made to be larger.
>>
>> The system is implementable with one developer working for about a week
>> and does not need a DLT or any other advanced distributed system to
>> operate. It can be placed as a single file on a standard web server.
>>
>> The specification is here:
>>
>> https://digitalbazaar.github.io/vc-status-rl-2020/
>>
>> Open source implementation is here:
>>
>> https://github.com/digitalbazaar/vc-revocation-list
>>
>> Checking credential status has already been integrated into vc-js here:
>>
>>
>> https://github.com/digitalbazaar/vc-js/commit/88e7971d39c1889c74f227d71a9812852f6485a8
>>
>> This email is:
>>
>> * A request for a second organization that would like to be
>>   listed as a co-editor on this specification.
>>
>> * An announcement that we will be opening a new issue to
>>   request adopting this as a work item once we get a second
>>   editor, and
>>
>> * A request for telecon time during our next meeting to
>>   socialize the specification in the CCG.
>>
>> -- 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
>>
>>