Re: Call for Focal DID Use Cases

On Sat, Jun 2, 2018, at 9:27 PM, Jordan, John CITZ:EX wrote:
> So, thanks Manu .. as I wrote that email I recognized the use case
> didn't specifically say only one DID / organization as you point out
> below .. however it is good if we are specific about that NOT being
> the case as there are many that still think this way as it seems
> "natural".> 
> I think I understand that we need use cases for the W3C process (I'm
> new to that process) ... what is a bit fuzzy to me is that DIDs are
> probably not something the people will be normally exposed to in their
> day to day digital interactions. It is sort of like IP addresses
> (except many per person and not geo located of course!) in that DIDs
> are addresses and they are for machines. Should the use cases be a bit
> more low level in that they could describe the types of peer to peer
> connections they enable, the ability to have verifiable credentials
> issued to them, and so forth. Having the DID addressable layer is 100%
> critical to the goals of being able to exchange trustworthy bits but
> they are a little under the covers.
For better or worse, there isn't  a definitive "W3C Use Case" template
or process. "Use cases" in the W3C sense are the preferred mechanism for
demonstrating the value proposition of proposed standards; however,
every use case document I've seen does it a little differently.
In ours, we are building on the work I did with the VCWG and the
Verifiable Credentials use case document [1]. That is currently going
through a major revision, where the "Focal Use Case" is how we do a
deeper dive on key use cases that illustrate in some detail the human
requirements driving the technical decisions.
My approach to use cases--and hence the approach I'm leading with to get
these written up for the chartering process--is to seek use cases that
illustrate* value-creating *interactions with a system, as far ahead of
technology design & implementation decisions as possible.
For example, in the domain of ATMs, "entering a PIN code" or "inserting
card" are not, in and of themselves, value creating and they embed
design choices. A few common ATM use cases that do create value are:   o Withdraw cash
   o Check balance
   o Transfer balance

It is possible to describe how each of these use cases occur with
minimal reliance on implementation choices. For example, you don't need
to mention a screen, keypad, card & reader, and a PIN. Instead, you can
talk about presenting options, identifying the correct account,
inputting the amount, authenticating the user, and authorizing the
withdrawal / balance check / balance transfer. This type of essential
representation allows downstream implementers to innovate how each
particular use case is satisfied, for example by using voice or
biometrics instead of a screen and card reader.
So, ideally, a good use case will illustrate that *because of DIDs*
individuals get uniquely valuable transactions with specific systems,
described with minimal reliance on the underlying tech. This will help
us understand the human requirements independent of the solution
designed to meet those requirements. If it is clearer to write it up
with the design choices, start there; we can tease out the most
relevant bits.
I encourage you to focus on the human experience that is enabled by DIDs
rather than the underlying mechanisms or protocols, except where they
MUST be described to illustrate the use case. My Joram paper from RWOT
[2] has several  examples where we  distilled the human experience with
minimal dependence on the technology.
The use case should describe *why* a use is uniquely valuable to real
people and *what* the persons involved do in their interactions, but not
*how* the technology does it. The latter part is the work of the
technical specification. The use cases should tell the tale of why DIDs
are different and valuable, independent of downstream design &
implementation choices. They should explain why people will value DIDs--
even, or perhaps especially--when they have no idea what's going on
under the hood.
To wit re: IP addresses: while IP addresses are generally hidden from
most users most of the time, they are vital to how the Internet works.
Key use cases that drove the development of IP were about network users
being able to maintain connectivity in the face of catastrophic failure
of particular servers on the network. What matters isn't how NATs or
switches or address blocks work, but rather that under distress (the
loss of components in the network), the rest of the network is able to
re-route and to the end user, "it just works".
In any case, I'll be working with use case authors to flesh out their
submissions.
Hopefully that helps.

[1] https://w3c.github.io/vc-use-cases/
[2] https://bit.ly/joram100 

> 
> I like the characterization of "single long lived identifier / single
> entity" ... I may borrow that if that is ok (> 
> Best
> J
> 
> 
> On 2018-06-02, 11:33 AM, "Manu Sporny"
> <msporny@digitalbazaar.com> wrote:> 
>     On 06/01/2018 03:37 PM, Jordan, John CITZ:EX wrote:
>     > I don’t think we need a single identifier like we have been
>     > trying to>     > unsuccessfully have in some places for years. I feel like those>     > numbers are a bad side effect of centralized database primary
>     > keys.>    
>     Agreed.
>    
>     > I think the reason I am quite resistant to a single identifier
>     > (if>     > that is what is being contemplated) for an organization is that
>     > in>     > the real world stuff happens.
>    
>     It was not what was being contemplated nor proposed, but I can
>     see how>     one could interpret the use case as such, so we should make it
>     clear>     that organizations/entities are expected to have more than one
>     DID.>    
>     I said an "Organization gets a DID"... that doesn't mean its the
>     /only>     DID/ the organization has.
>    
>     This group has identified the "single long lived identifier /
>     single>     entity" (e.g. SSN, DUNS, email address for identification) design
>     as a>     privacy concern in the VC spec here:
>    
>     https://w3c.github.io/vc-data-model/#identifier-based-correlation>    
>     and here:
>    
>     https://w3c.github.io/vc-data-model/#long-lived-identifier-based-correlation>    
>     We list the "desirable ecosystem characteristics" that we want
>     here:>    
>     https://w3c.github.io/vc-data-model/#use-cases-and-requirements
>    
>     So the change that needs to be made to the Decentralized Corporate>     Identifiers use case is:
>    
>     Clarify that organizations will have more than one DID, typically
>     scoped>     appropriately to the interactions that they will perform using the
>     DID.>    
>     -- manu
>    
>     --
>     Manu Sporny (skype: msporny, twitter: manusporny, G+: +Manu
>     Sporny)>     Founder/CEO - Digital Bazaar, Inc.
>     blog: The State of W3C Web Payments in 2017
>     http://manu.sporny.org/2017/w3c-web-payments/
>    
>    
> 

--
Joe Andrieu, PMP
joe@joeandrieu.com
+1(805)705-8651
http://blog.joeandrieu.com

Received on Sunday, 3 June 2018 20:00:27 UTC