Relationship Cards (R-Cards)

So much for the naive thought that I’ have time at the Burton Catalyst conference last week to finally blog about two subjects near and dear to my heart that I knew would be covered at the conference. It backfired because they were too topical — all available time was consumed by related conversations.

I did manage two posts about the first one — launch of the Information Card Foundation — about which there will be much more to say in the coming months.

But the other one — relationship cards — is long overdue. I first promised to blog more about r-cards after both doing a demo and hearing Bob Blakley’s fantastic talk on The Relationship Layer at Spring IIW in May. Then Joe Andrieu and Eve Maler both posted about them and asked me to add more details. Then I fell into an abyss of work (actually building this stuff) from which I have yet to climb out.

But Bob’s new talk on The Relationship Layer at Catalyst last week, followed by Eve’s talk on The Care and Feeding of Online Relationships, plus the upcoming VRM (Vendor Relationship Management) Workshop at the Harvard Berkman Project on July 14-15, compels me to finally post about why I believe r-cards may be what finally pushes Internet identity across the chasm.


First: what is a relationship card (“r-card”)? At the most general, the definition I would offer is:  “a digital object instantiating a mutually authorized data sharing relationship between two or more parties on a network”. The abstraction is intentional: the generic concept of an r-card, like the generic concept of a folder, a link, or a network, can take different forms in different implementations.

To take a step more towards the concrete, the concept of an r-card was conceived at the Higgins Project as a new kind of information card (i-card). For their part, i-cards were first conceived by Kim Cameron and team at Microsoft, where they have been promoted as a key element of Microsoft’s vision of an identity metasystem. These memes subsequently took hold at Higgins, among other places, where the concept of an i-card was generalized to the definition that currently appears on Wikipedia:

An i-card is a rectangular icon displayed in the user interface of an identity selector (sometimes also called an identity agent) that represents a digital identity–a set of claims about some entity (typically a person, but it could also be an organization, application, service, digital object, etc.).

The i-card metaphor is based on familiar physical identity credentials like business cards, credit cards, library cards, association cards, driver’s licenses, badges, etc. However, just as computer file folders are similar to but more powerful than real-world file folders, i-cards are similar to but more powerful than real-world identification cards. The i-card metaphor is identical to the information card metaphor used in numerous identity selectors.

So what distinguishes an r-card from a plain-vanilla i-card? The capability to instantiate an ongoing data sharing relationship. In other words, a standard i-card invokes a one-time exchange of a set of digital claims using a security token. An r-card, by contrast, exchanges a set of claims and associated policies that enables both parties to continue to share other information over time, e.g.:

  • Updates to the initial values of the claims
  • New claims
  • Permissions and controls over communications via other channels
  • Changes to the r-card itself

A simple analogy would be: a standard i-card is like showing your driver’s license to a bartender to prove you are of age: you use it once and put it away. An r-card is much more like giving a business card to an associate or a customer: it is an invitation for an ongoing relationship via the address(es) and other information shared on the card.


But while instantiating a private data sharing channel by exchanging a digital object is cool — sort of like RSS on steriods — for some reason that aspect alone doesn’t capture the real power of r-cards. Case in point: after a live participatory enactment of how r-cards work with audience members during the first day of IIW in May (all based on business cards, scissors, and string — no computers involved), several audience members came up to me and said, “Why didn’t you show this years ago? Anyone can understand the value of r-cards. They are the most compelling use case we’ve ever heard for all this Internet identity stuff.”

After that experience, even I was trying to grok what it was that made r-cards so intuitive and attractive. I was having trouble putting it into words until I was listening to Bob Blakley’s talk on The Relationship Layer again at Catalyst last Wednesday morning. At the midway point, he put up an “intermission” slide with five bullets summarizing the first half of his talk. Two of them hit me like they were shot out of a gun:

  • Relationship is the context which protects the security and the privacy of identity information.
  • Identities are built in the context of relationships.

This Copernican revolution Bob was proposing — that relationship is really the sun around which identities orbit — suddenly made me look at r-cards in a new way. It wasn’t just that r-cards enabled bidirectional data sharing. It was that r-cards create the context for a relationship. And by doing so, they call forth all social dynamics of real world relationships that are often missing on the Web today. Dynamics like:

“I am more inclined to trust you because we both know if you break that trust, I can terminate the relationship.”

“Of course you wouldn’t share our private shared information outside our relationship — friends always respect each other’s privacy.”

“Each of us shares information in proportion to the value it brings to the relationship — both of us are incented to build that value.”

That’s why people find r-cards so intuitive — they are a way of creating and managing the same balanced, mutually-controlled, give-and-take between two parties over a network that we have in the real world relationships we manage every day. And they can apply to any form of relationship — person-to-person, person-to-community, person-to-employer, person-to-vendor, etc.


Okay, okay, at this point I know all the geeks are screaming “enough with the soft stuff — where”s the technical beef??” I don’t want to duck that question, because as I’ve told Joe Andrieu, chair of the VRM Standards group, I’m knee-deep in it every day. But with the limited time I have left for this post, I can only give the high-level recipe we are currently putting to the oven test at Parity and the Higgins Project:

  • Take a conventional i-card as currently defined by the Microsoft ISIP documents (which can’t get into an SDO fast enough).
  • Add an OpenID — or to be precise, an identifier on which you can do XRDS discovery to locate a data sharing endpoint. In Higgins we call this form of identifier a UDI (Universal Data Identifier).
  • When the r-card recipient receives the r-card, use the UDI to perform XRDS discovery of an Internet data sharing protocol supported by both parties.
  • Intiatite data sharing via the selected protocol, using the UDI and other supporting claims on the r-card as necessary.

Of course readers of this blog know what data sharing protocol I have in mind: XDI — specifically the XDI RDF model. It’s particularly well-suited to r-cards because XDI link contracts provide a portable, machine-readable description of the mutually-agreed data sharing controls. But it’s important to clarify that any data sharing protocol supported by both parties will work. As an example, Asa Hardcastle showed a wonderful demo of OpenID-enabled Liberty ID-WSF at Spring IIW, and we are deep in conversations about how UDI discovery for ID-WSF endpoints can work. OpenID Attribute Exchange is another option because any OpenID identifier can already support XRDS service discovery.


I know that’s only the tip of the iceburg, but this is a huge topic that I’ll be posting about for months. For example, in Bob’s talk he showed a relationship schema that he, Lori Rowland, and their colleagues at Burton group have already started to develop. I eagerly anticipate working with them to map that to XDI link contracts to make sure we have all the bases covered.

And I’d like to find time to start posting some example r-card XDI messages using super-simple X3 format to illustrate common use cases like the VRM personal address manager.

But right now I’m going to work on maintaining a particularly important relationship — with my wife — by getting to bed!


About Drummond Reed

Internet entrepreneur in identity, personal data, and governance frameworks
This entry was posted in Data Portability, General, Higgins, I-Cards, Identity Rights Agreements, Information cards, R-Cards, Relationship cards, Social Web, VRM, XDI, XRDS and tagged , , , , , . Bookmark the permalink.

2 Responses to Relationship Cards (R-Cards)

  1. Mike Jones says:

    Sounds to me like your current r-card definition would let relationship cards be supported by the Identity Selectors that already exist today with no changes, because an r-card is simply a managed Information Card with a special claim: an identifier on which you can do XRDS discovery. That would be really good, as you’d signficantly increase the technical reach of relationship cards by defining them to use those existing underpinnings.

    Best wishes on birthing this new creation!

    — Mike

  2. Pingback: Equals Drummond » Blog Archive » Principles of VRM

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