Abstract

This document is a product of the User-Managed Access Work Group. It records the scenarios and use cases governing the development of the User-Managed Access protocol and guiding associated implementations and deployments.

Status

This document is currently under active development. Its latest version can always be found here. See the Change History at the end of this document for its revision number.

Editors

Eve Maler

Intellectual Property Notice

The User-Managed Access Work Group operates under Option Liberty and the publication of this document is governed by the policies outlined in this option.

Table of Contents

Introduction and Instructions

This document is a product of the User-Managed Access Work Group. It records the scenarios and use cases governing the development of the User-Managed Access protocol and guiding associated implementations and deployments, and outlines technical issues raised thereby.

Please use the scenario template near the end of this document in adding new scenarios and subordinate use cases. Change the status keyword in each scenario and use case title as appropriate, linking to the meeting minutes page explaining the status change:

• Pending: Initial status when first submitted
• Accepted: Needs to be accounted for in UMA V1 and/or its associated compliant implementations
• Deferred: Relevant to the problem space; may be considered in future versions
• Rejected: Out of scope

Edit the descriptions of technical issues and scope questions to reflect (or point to) group decisions about how to handle them.

Scenario: Sharing a Calendar with Vendors (Pending)

Submitted by: Eve Maler

Online calendars are an example of personal data that is readily shared with other people in a manner that evokes VRM paradigms. Because calendar data is fairly volatile, static calendar snapshots are rarely shared; rather, a calendar feed is provided and authorized recipients can pull fresh calendar data as required. The data is often considered sensitive and is expected to be kept secure, hence "private URLs" and (minimal) ACL features offered by Google Calendar and other hosts.

In this scenario, personal online calendars are shared with "vendors" (online services) rather than other individuals, and they are shared in such a way as to allow permissioning and auditing from a central location rather than wherever the calendar is hosted. For the purposes of this scenario we'll focus on sharing a single online calendar (such as for "work", "soccer", or "travel") as a unitary Web resource, on an ongoing basis, with one or more individually-authorized recipients.

User interface mockups of a calendar-sharing interaction can be found in the initial blog post made about ProtectServe and, in somewhat more sophisticated form, slides from a speech made at an identity conference.

Following are some motivating circumstances in which calendar-sharing with vendors may make sense. (NOTE: All references to real vendors are hypothetical.)

Travel Calendar Sharing with Vendors

Alice, who is based in the Seattle area, has an online calendar that specifically contains business travel details such as flights, hotel stays, and car rentals, and since she travels quite frequently and often to international destinations, she wishes to share it with the following vendors:

• Her Visa credit-card company, Chase
  
  Often when she tries to charge European hotel stays to her Chase Visa, the credit card company denies the charges or asks the hotel desk clerk to put her on the phone to make sure it's really her flitting around Europe and racking up big hotel bills. To let Chase know ahead of time what her travel plans are, Alice decides to share her travel calendar with them on a long-term basis so they can know ahead of time that it's likely truly Alice who's putting a Barcelona hotel stay on the card.
  
  Note that this recipient of her data already has a lot of quite personal and sensitive information about Alice, so she's fairly comfortable giving them access to this data under certain conditions, such as refusing to accept third-party direct marketing.
  
  It must be possible for Alice to cut off the flow of travel calendar data to Chase (even though she continues to use that card for personal purchases) when Alice is told that she has to begin using a corporate AmEx card for all business travel purchases.

• The Seattle Times newspaper delivery service
  
  She'd like to avoid having to go to their website to put her newspaper delivery on hold every time she travels. By sharing a travel calendar with the delivery service that accurately reflects when no one will be at home, she saves one more to-do item as she prepares for each trip.
  
  This is data she would have had to share with the service "manually" anyway (by filling out a web form or using the phone), so she already had to trust the service not to rob her house while she's away. It's likely her full travel calendar contains more data than the service strictly needs, however.

• The U.S. Postal Service
  
  Instead of having to go to the Post Office or its website to fill out a mail hold form, she wants to let them know automatically. This is very similar to the Seattle Times situation, but in our project we need to solve for being able to attach different data-sharing policies and possibly have a different data-sharing lifespan between the two.

• Her mobile carrier, T-Mobile
  
  Alice would like to be offered the option to purchase pre-paid roaming minutes when she travels overseas. By sharing her travel calendar, she can let T-Mobile know that she'll be in Brazil next month and would welcome a special offer on mobile roaming. (Note that this use case has an element of volunteered personal information to it; by positively choosing to share her information, Alice gets new opportunities to transact with vendors.)

• Her travel data social-networking sites, Dopplr and TripIt
  
  Alice wants to keep all her "source" travel information in one place, but some of her friends and colleagues use different Web 2.0 sites to share such information. Rather than re-input all her travel destinations into Dopplr and TripIt, she'd like to let them pick up her planned locations and trip dates from her travel calendar.
  
  Today, Dopplr and other similar sites often use OAuth to share such information, but the actual data passed isn't standardized, and the protocol for creating that long-term connection between the sites is OAuth. (See the forthcoming scenario Granting Service Access to a Photo Set for more observations on this flavor of scenario.)

Soliciting Timely Interactions from Vendors

Alice happens to work from home. Her typical work day is very busy, and she rarely has time to sit on hold when calling the various vendors in her life. She has a calendar that exposes the times during the day when she is free to accept a phone call or consider an invitation to a meeting or other event. She would like to share this information with the following vendors:

• Her TV cable carrier, Comcast
  
  Alice's TV cable system has stopped working, and she needs to have a Comcast repairman come over to the house to fix it. She's too busy to spend time jockeying with the customer support person on the phone about which three-hour period she might be free, so she decides to let Comcast get a limited view into her potential free times so they can send her an event invitation for a repair slot.

• Her general-practitioner doctor's office
  
  Alice needs to talk to the medical assistant in her doctor's office, but it's impossible to get hold of her. The MA calls while Alice is on a telecon but the MA can't leave a substantive message because of HIPAA laws/fears, and then when Alice calls back, of course the MA is in the middle of making a series of other calls and can't be reached. It's a "telephone tag" nightmare. Alice would like to share her free/busy times for the next few days so that the MA can at least pick a likely time to call her successfully.

Use Case: Separate Resource Host, Relationship Manager, and Recipient (Pending)

Submitted by: Eve Maler

The most generic possible configuration of protocol endpoints solving this scenario is to have one service hosting the calendar in question, a different service getting permissioned read access to it, and yet a different service functioning as the authorization manager, all of them "in the cloud" from the perspective of the user and all operating on the open Internet rather than on a corporate intranet (since our user is an individual acting on her own behalf). This configuration is illustrated below.

Scenario: Granting Service Access to a Photo Set (Pending)

Submitted by: Eve Maler

Today, many Web 2.0 services are beginning to offer users features that depend on connections with other third-party services, using OAuth to forge the connection. A classic example is configuring your photo-hosting site to use some other photo-printing site to print your photos. Whereas the Sharing a Calendar with Vendors scenario primarily focuses on sharing data whose "substance" (your calendar entries) vendors then "consume" to give you interesting service, this scenario primarily focuses on granting service access to other services in order to get combinatorial effects from the service features themselves.

In this scenario, access to photos is shared with other services that can do interesting things with them, in such a way as to allow permissioning and auditing from a central location rather than wherever the photos are hosted. Since it is just as likely that multiple photos might want to be subjected to this treatment as a single photo would be, we'll assume a set of them. Each third-party service is intended to be granted access separately, on possibly unique terms.

This scenario is a bit similar to the Sharing a Calendar with Vendors circumstance in which calendars are shared with Dopplr and TripIt.

Following are some motivating circumstances in which photo access may make sense. (NOTE: All references to real vendors are hypothetical.)

• Making a feed or stream of photos available for printing and mailing to a recipient
  
  This situation is based on that described in item #8 (alternative) of the photo-sharing scenario from the IIW8 Use Case Selection and Metrics session in May 2009: "Grandma doesn't do stuff online, but subscribes to a service that prints and sends her photos. Peter wants to give printing/sending access rights to the service." You, as the photo owner, may want to commit the printing service not to use or further share the photos beyond this task, and may want to audit their periodic retrievals of photos for printing and mailing.

• Using a service that creates photo thumbnails and other reduced-size versions
  
  In this case, you are giving "read" access to your photos, but also "write" access to hold the results of the processing. This is perhaps similar to the way some OAuth-connected location services can either read your location from, or write your location to, each other.

Use Case: Consumer Uses Complex API to Interact with SP (Pending)

Submitted by: participant-name

The generic configuration involves a consumer interacting with a separately hosted service provider in some intelligent way based on the SP's capabilities and expectations. This configuration is illustrated below.

Scenario: unique-title (Pending)

Submitted by: participant-name

(Provide description of the scenario with all nontechnical particulars, noting requirements, constraints, and other observations. Avoid diagrams.)

Use Case: unique-title (Pending)

Submitted by: participant-name

(Provide description of a use case matching this scenario with all technical particulars, such as the topological configuration of protocol endpoint entities, potential wireframes, listings and assessments of technical issues, and anything else helpful.)

Issues

Following are discussions of technical issues raised by one or more scenarios and use cases. Acceptance of a scenario or use case will imply agreeing to develop a satisfactory solution to applicable issues.

Issue: Policies Specific to the Web Resource Type

Related to: calendar scenario, photo set scenario

There is a potential need to restrict, anonymize, blur, or otherwise transform a shared resource, possibly based on the unique characteristics of its content type.

With respect to calendar resources, the premier calendar format standard already accounts for a blurring of data details by providing a "free/busy" option in addition to a full-data option. It feels like it should be out of scope to solve for filtering the calendar data cleverly (beyond the format's natural capabilities) to hide Alice's destination, hotel, etc. (though generic solutions such as making events taggable, and then filtering on the tags in a relationship manager interface, come to mind). An "identity oracle" approach (filtering the data into a completely different type) might be necessary if what Alice is trying to convey is simply "don't deliver my newspaper on these days" vs. "here's all of my travel information".

With respect to service access to photo sets, today's OAuth usage is instructive. Every OAuth service provider has the opportunity to offer unique and interesting policies that relate specifically to its connection with certain other applications. It might be the case that some policies simply can't be externalized into an authorization manager, or that greater communication between service providers and authorization managers need a wider and more frequent communication path so that users can apply even SP-specific settings while visiting their relationship manager.

Some data-usage policies and terms may possibly have an interaction with some resource types, such as requiring recipients to discard volatile data after a period dictated by the data's type.

It has been observed that if fine-grained calendar filtering were a solved problem, different calendar sites could be shared with different friends as a way of managing minimal disclosure through indirection.

Issue: Authorization Manager Endpoint Discovery

Related to: calendar scenario, photo set scenario

The mockups linked in the calendar scenario imagine that the user's authorization manager endpoint (what we imagine Alice will perceive as the name of her relationship management service) will be handled as if it were an OpenID, with introductions to popular relationship manager services offered in an array by potential UMA service providers much in the way that the RPX solution presents options. (The user always has the ability to self-host an authorization manager endpoint, similarly to self-hosting an OpenID provider – and they might even be colocated.)

Issue: Handling the Resource URL and Provisioning It to the Consumer Site

Related to: calendar scenario, photo set scenario

The mockups linked in the calendar scenario imagine the simplest possible situation: The Consumer site literally asks for exactly the kind of information it needs, and the user copies and pastes a URL into a field.

This is how calendar feeds, photo streams, RSS feeds, and other such resources are shared today; it works but we need to consider its scalability to arbitrary types of information. There are several challenges here: The Consumer's ability to handle the information, its way of expressing the desire/need for the correct information, and the user's (or user agent's) ability to provide it in a convenient and correct fashion.

In addition, the relationship manager interface is shown having some knowledge of that resource as a unique object. We need to consider how to let the AM and SP communicate about this information appropriately.

In the case of the photo set scenario, note that in OAuth usage today, the resource-based interaction is often accomplished silently from the user's perspective: the desired combinatorial effect simply "happens" as if the feature that was "outsourced" to a third-party app were native. Perhaps this is possible in the UMA approach.

Issue: Processes By Which Consumers Meet the User's Data-Sharing Terms

Related to: calendar scenario, photo set scenario

Some of the vendors mentioned in the calendar scenario are big companies; can standard (and machine-readable) data-sharing contract terms be developed and pre-negotiated such that, when such contracts are offered by an individual, they are likely to be accepted and met? Small companies such as a modest medical practice may need a human-accessible interface and the option of an "I Agree" button so that the person manually fielding Alice's offer of data can complete the transaction.

It may be necessary for us to consider "partial measures" in the V1 UMA effort to improve adoption. Some such measures are: terms that can be passively accepted ("I Agree") rather than terms that require positive demonstration of intent (such as payment receipts); policies that don't require explicit agreement on the part of the recipient but are somehow attached to the data supplied ("sticky policies"); and policies about which the recipient is merely informed rather than asked to agree with.

Change History