Re: DID Use Case: Public Pointers to Private Data

On Wed, Jun 13, 2018 at 4:21 AM, John, Anil <anil.john@hq.dhs.gov> wrote:

> I had help to sanity check my intent : -)
>
>
>
> Your mention of the ‘sovrin protocol’ also brings to light one of my
> concerns in this area which is that there needs to be careful thought given
> to what is part and parcel of the base DID spec and what is spun out to be
> the responsibilities of DID enabled implementations like Sovrin or Veres
> One or others.
>

I have always felt the line is quite clear: there is the DID layer of
interoperability, and then the "decentralized P2P protocol" level of
interop, i.e., the protocol that any two DID-identified peers can use to
talk.


>
>
> I am concerned that this type of design choice conversation is not
> happening in public, and that the standard response seems to be (1) We are
> thinking about ANOTHER spec for THAT or (2) It is supported in the
> [implementation] protocol.
>

The Sovrin protocol is being developed very publicly by the Sovrin
Foundation <http://forum.sovrin.org/>, in part because W3C explicitly put
protocol out-of-scope when it chartered the Verifiable Claims Working
Group. There are of course other open standard P2P data exchange protocols
that could be used, including UMA and OASIS XDI, but neither of those has
been focused directly on the nuances of verifiable claims exchange, and in
particular using zero-knowledge proofs for selective disclosure. That's the
focus of the Sovrin protocol, the standard implementation of which is
available as open source code in Hyperledger Indy
<https://chat.hyperledger.org/channel/indy-agent>.

Best,

=Drummond


>
>
> Best Regards,
>
>
>
> -          Anil
>
>
>
> *From:* =Drummond Reed <drummond.reed@evernym.com>
> *Sent:* Wednesday, June 13, 2018 12:09 AM
> *To:* John, Anil <anil.john@hq.dhs.gov>
> *Cc:* W3C Credentials CG <public-credentials@w3.org>
> *Subject:* Re: DID Use Case: Public Pointers to Private Data
>
>
>
> Anil, this is beautifully stated. I'll note that within the Sovrin
> ecosystem, standardizing how access to a resource can obtained via a Sovrin
> agent endpoint listed in a DID document is one of the primary purposes of
> the Sovrin protocol <https://github.com/sovrin-foundation/protocol>. The
> authorization method is of course based on verifiable credentials. Much
> work is still to be done, but you have stated the need, the challenge, and
> the distinction of the work very well.
>
>
>
> =D
>
>
>
> On Tue, Jun 12, 2018 at 11:59 AM, John, Anil <anil.john@hq.dhs.gov> wrote:
>
> Name
>
> -------------------
>
> Public Pointers to Private Data
>
>
>
>
>
> Background
>
> -------------------
>
> When sharing information between multiple organizations, each participant
> typically segregates data that is publicly visible from data that is
> considered private. It is useful for organizations to provide the public
> information in a way that is cryptographically verifiable and includes the
> ability to point to data stores containing associated private information.
> This private information should only be accessible to authorized entities
> on an automated, case by case basis.
>
>
>
>
>
> Need
>
> --------------------
>
> A national customs and border authority facilitating and enforcing the
> movement of goods across its border is automating and streamlining the
> sharing of relevant documentation from trade organizations. The customs
> authority asks each trade organization to self-issue an identifier that
> enables them to create digital signatures for the purposes of signing
> documentation and authenticating themselves. When a trade organization
> ships goods across the border, it uses the identifier to digitally sign and
> share data that is visible to the customs authority and other trade
> members. When and what data was provided by the trade organization is
> auditable, including pointers to private, trade-sensitive, access
> controlled data. When the customs authority is performing an inspection,
> (a) it reads and verifies the public data and private pointers, (b)
> retrieves a cryptographic access token that only they can use to access the
> private data, and (c) accesses the private data using the cryptographic
> access token.
>
>
>
>
>
> Challenge
>
> -------------------
>
> While the public records are accessible to the customs authority and the
> trade organizations, the private records are only accessible to the customs
> authority or someone that they delegate the access token to. There are
> three protocols at play here: (1) accessing the public records, (2) using
> the access token for private access, and (3) the mechanism used to
> authenticate during the private access and the subsequent authorization to
> see the relevant private data.
>
>
>
>
>
> Distinction
>
> -------------------
>
> This use case identifies the notion that DIDs and DID Documents will
> enable architectural models and protocols that have a public and private
> component to them. The identification of each actor in the ecosystem and
> all three protocols in the challenge  are dependent on the authentication
> and authorization mechanisms supported/referenced by DIDs and DID Documents.
>
>
>
> This use case also suggests that naturally delegatable authentication and
> authorization mechanisms should be considered in order to reduce
> operational overhead and avoid privilege escalation problems when accessing
> these private systems.
>
>
>
>
>
> Best Regards,
>
>
>
> -          Anil
>
>
>
> Anil John
>
> Cyber Security R&D Program Manager
>
> Science and Technology Directorate
>
> US Department of Homeland Security
>
> Washington, DC, USA
>
> anil.john@hq.dhs.gov
>
>
>
> Email Response Time – 24 Hours
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