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.
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 copy and revise an existing scenario in adding new scenarios and subordinate use cases. Each scenario is created as a separate child wiki page with a name like xyz_scenario and then linked from here. Change the status keyword in each scenario and use case title as appropriate, linking to the meeting minutes page explaining the status change:
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 (Accepted)
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:
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:
Use Case: Separate Resource Host, Relationship Manager, and Recipient (Accepted)
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: Packaging Resources for E-Commerce Vendors (Accepted)
Submitted by: Eve Maler
This scenario focuses on the typical set of information that we hand over to online vendors repeatedly, and the desire to avoid sharing the data "by value", instead focusing on how to share it "by reference" (pointers).
Let's look at how an online buying scenario might look today.
Following are some key questions we can ask, identified by whether they capture an identity management (IdM) issue, a vendor relationship management (VRM) issue, or a social networking issue. (Note that some of these questions highlight scenarios and use cases that the calendar scenario has already captured. Some of these might want to get turned into unique use cases for this scenario.)
Maya shares the information about herself that Staplers.com needs at the beginning of her e-commerce relationship with them, but instead of having to share it "by value", she shares it as some form of pointer to a package of resource pointers that Staplers can dereference and refresh as they needs to over time. She can change the underlying information whenever she wants to without worrying about paying special attention to Staplers (or any of the other hundred e-commerce sites with which she has registered.
Use Case: Online Purchase with Setup of a Long-Running Account Relationship (Accepted)
Submitted by: Eve Maler
Preconditions: Maya has already stored, and packaged together, pointers to the set of relevant resources frequently needed for online purchases:
Use Case: Engaging in a Purchase "One-Night Stand" (Accepted)
Submitted by: Eve Maler
This is the same as the first use case outlined above, except that Maya provides her resource package not as part of a request to register a new account, but as part of a one-time purchase. (Some websites today allow for purchases without registering, and are prepared not to give you a browser cookie or retain your information beyond necessary for the purchase and its aftermath.)
The policies Maya chooses in this case are likelier to be more stringent about not retaining personally identifiable information (PII) for any significant length of time, and may ask the vendor to generate "positive" assurance messages about policy adherence (not just silent adherence).
(The protected-inbox scenario might play an especially important role if Maya is engaging in a one-night stand purchase, since it enables the vendor to report product recalls and such to Maya without her having to expose other more compromisable communications endpoints such as persistent email addresses or phone numbers.)
Scenario: Online Personal Loan request scenario (Accepted)
Submitted by: Domenico Catalano
The Economy downturn and the Financial institution crisis have introduced new needs to increase the control on loan or mortgage request process verifying user credit information and user status, in order to reduce financial risks.
Online Personal loan request is a specific use case in which a user/customer apply a request for a personal loan to a financial service.
Today, human interactions are based on online access to Financial Risk Central Service, by Financial service operator, or operator telephone call to user's bank to verify account or to the user's Employer to verify employee status, ect.
Scenario: Distributed Services (Pending)
*Submitted by:* Christian Scholz
(this text is just to describe one possible environment in which distributed or mass authorization of services is useful)
If you look at the social networking scene today one thing is obvious already: There is lot of data online on various services and much of this data is redundant because it is available in various copies which are usually not synced. The main area for this problem is probably profile and friendship/contact information. On each social network or service you register you usually have to enter your profile information again and try to find your contacts.
With the advent of more and more of such social services the amount of redundant data will grow even more and this will lead to a acceptance problem.
The Service Catalogue idea
It is unlikely that users will centralize all their data in one place. It's more likely that data will be distributed even more. So one problem might already be to manage all the places where data is stored about you or where services can provide functionality on your behalf. One solution to this might be a concept called "Service Catalogue" which came up in discussions in the open web/DiSo/DataPortability communities. The basic idea is to have a list of all these places stored under your control which can be queried by services.
Another point is that for reducing the amount of copies of your data it is necessary to link to your data instead of copying it (or even worse asking the user to type it in again). The Service Catalogue can serve basically as such a link list where each service/type of data is marked up with a location (URI) and type (probably another URI). Obvious things to link to are your profile and contact list but other things make also sense, like photos, videos, blog posts, recommendations, your attention profile, travel information and much more.
Having this catalogue you can easily tell a new service which other services you already use by simply pointing it to the Service Catalogue:
Note though that this Service Discovery is out of scope for the work at UMA and only serves as an example of how to obtain a list of services to authorize later on. Another method apparently is the user typing in various URLs which is not that user friendly though.
The result is in any case a list of services you want to authorize.
The problem is how you authorize that new service to get access to all the other 3rd party services. OAuth is one possible solution but at least if the default mechanism for retrieving a token is used this means that the user has to be redirected to each of these 3rd party services in order to give consent for the new service to use that data.
Moreover OAuth does not contain a mechanism to define what permissions should be used on the service endpoints. This can be done individually by each service but having a central place for such policy decisions and being able to store policies and share them among services might be beneficial as well.
An example for such profiles would be that you can filter which fields of your profile a PortableContacts endpoint actually gives out to a certain consumer.
For the sake of usability what we want is a single page where you can define the relationships between that new service and all the other services you have access to.
This could look like this:
Additionally a user should be able to quickly revoke tokens again in a central location as well as getting an overview of which services have access to which other services under which policies.
Scenario: Controlling Two-Way Sharing of Location Information (Pending)
Submitted by: Eve Maler
Today's location services such as FireEagle, BrightKite, and Dopplr let Alice set her location within any one of several applications, and then use OAuth-enabled connections to propagate that information through other such services. Since Alice can end up "chaining" services this way quite easily, with a thicket of pairwise connections, it's valuable for her to know and control where this information is flowing to. In this scenario, a user of HotLocale and RovingRound wants to arrange to connect them up so that her location can be propagated among them, and she wants to get a global view through her AM about who's allowed to do what, so she can change and stop permissions in a coordinated way.
Note: This scenario is not exploring anything other than person-to-self sharing. How Alice exposes her location to other people and companies should be the subject of a different scenario, as warranted.
Below is a screenshot showing that FireEagle and Dopplr have the capability today to have two-way location information flow. Our user wants to be able to see this "combinatorily", for all connected location services and indeed for all such services on the web that she chooses to use for hosting any data or content.
Assumptions and Preconditions
This scenario assumes that Alice has an account at each of AM, H1, H2, R1, and R2. These accounts might or might not be driven off of federated login, for example, Alice might log in to HotLocale through Google and RoadWarrior through Facebook.
This scenario assumes that AM, H1, H2, R1, and R2 are all UMA-enabled but have otherwise not met before. (Simplified circumstances that assume prior introduction are described in their turn below.)
This scenario assumes that H1 and H2 use a hypothetical standard location API that R1 and R2 are configured to understand, and that H1 and H2 expose APIs through URLs that differ per user in some fashion (e.g., through a URL query parameter or through a part of the URL path).
Use Case 1: Alice Sets Up AM Protection Over Location Information at HotLocale
This flow can be embedded in other flows, or can be standalone.
The identical sequence can be done with HipHappeningPlaces (H2).
Use Case 2: Alice Shares HotLocale Location Access with RovingAround and RoadWarrior
The identical sequence can be done with RoadWarrior (R2), except that once HotLocale is introduced to the AM, it never needs to be introduced again, so the optional embedded UC1 block isn't ever done again unless Alice wants to switch AMs.
Use Case 3: Alice Monitors and Controls Location Information Access from Her AM
To monitor access, Alice interacts with value-added functionality provided at the "data-sharing relationship manager" application that serves as her AM endpoint; that is, this use case does not involve standardized UMA protocol behavior. These interactions might include:
To control access, Alice may take various actions:
Scenario: Requester Delegate (Accepted)
Submitted by: Michael Hanson
The Requester may be using a hosted service, which may need to make requests on its behalf.
The user has entered a relationship with BizService, and wants to authorize it to access her calendar. BizService is using a website hosted by BizTools, which is the entity that will initiate all network activity and actually hold the tokens generated during the transaction.
The user should be able to authorize BizService to access her data, without granting any privileges specifically to BizTools, and without granting privileges to any other company hosted by BizTools.
Use Case: BizTools Impersonates BizService (Accepted)
Today, app-hosting relationships commonly involve sharing of private keys (covered by service-level agreements), and concomitant "impersonation" of the company by the outsourced service. This use case would seem to be transparent to the user (for example, if the user is given a real-time opportunity to consent to access when BizTools/BizService attempts it, the request will appear to come from BizService) and to the UMA protocol.
Use Case: BizTools Provides Its Own Network Endpoint (Rejected)
If BizTools approaches the resource not by impersonating BizService but in its own right (on BizService's behalf), true delegation would somehow have to come into the protocol picture. The goal would be to avoid creating an "omnipotent token" that allows the proximate Requester (BizTools) to use the token for access on the behalf of other parties. As discussed on 2009-10-08, we are inclined to reject this use case.
Scenario: Managing Information in Which Employers and Employees Both Have a Stake (Pending)
Submitted by: Eve Maler
Both an employer and their employees might want to impose their own constraints on the sharing of the same employee-related resource. Examples of pieces of information your employer holds that you might want to share with others:
Some additional ones listed in the Liberty ID-SIS Employee Profile Service specification:
The following “user stories” capture the distinctive aspects of this scenario:
See the use cases below for the different configurations in which the actors might appear.
Issue: In large companies, typically the function of verifying someone's employment is outsourced to a specialized company. The employer is still seen as authoritative for employment status and other such data, though. For such information, where in the use cases below the employer is assumed to be the authoritative Host, perhaps the employer needs to provides a pointer to the employer's chosen verification service resource, such that the resource being shared is a pointer to a pointer (double indirection). Or perhaps the employer instructs Alice to introduce her AM to the real Host directly.
Use Case: Employer as AM and Host (Pending)
Submitted by: Eve Maler
Here, the employer runs an employee profile self-service application that could include both AM and Host functionality. The AM could let Alice configure her sharing policies, but could also let Alice know that it will be enforcing additional constraints out of band with respect to UMA.
This is probably a “legacy” solution because it forces the employee to seek out other relationship managers in the outside world where they’re just an individual rather than an employee, and it seems the employer would be hosting the AM only for corporate inertia (admittedly, a force to be reckoned with).
Use Case: Employer as Host (Pending)
Submitted by: Eve Maler
For information for which the employer is authoritative (”Is this person employed here?”), it could offer a Host willing to attest to this on request (in accordance with the instructions issued by Alice's personal AM). If the employer doesn’t want to release the data even though the employee wants to allow the sharing, it could use existing access control mechanisms that are out of band with respect to UMA.
Issue: Should the employer-Host surface a response code to the Requester that reflects this type of refusal? Should it provide audit-log data back to the AM?
Use Case: Employer as Requester (Pending)
Submitted by: Eve Maler
For information that Alice already self-asserts to the employer (”What is the employee’s home address of record?”), the employer should ideally consume this data in the same way some other “vendor” (online service) on the open Internet could. If the employee moves, a number of workflow actions have to unroll on the employer’s side as they would have anyway (in the U.S., moving to a different state might involve withholding a different amount of state income tax), but this is already handled in existing systems when the employee provisions the new information into employee profile apps by value. An on-board “personal datastore” Host is shown here with the user’s chosen AM, but the Host could just as easily be remote.
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
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".
In the Controlling Two-Way Sharing of Location Information scenario, note that FireEagle allows a user to choose to share locations only at the city level, and this level happens to be chosen for the connection that authorizes Dopplr to read the FireEagle location (a different level can be chosen for each application that reads location from FireEagle). As it happens, Dopplr does not offer the same policy capability. Without having to teach UMA generically about all the possible policy options specific to all the kinds of information in the world, is it possible for each Host to teach each AM about the policy options it offers, in some way that lets the the relationship manager application surrounding the AM present user interface options to see and select these policies? Seeing may have less protocol impact than selecting, and seems to be a minimum value-add if the goal is to allow OAuth users to get a global view.
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
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 Hosts 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
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: How Terms can be Met
An AM has two major tools at its disposal in allowing access to a user's resources: policies declared by the authorizing user, and terms which the Requester must meet in order to gain access. To a first approximation, policies can be unilaterally applied, whereas terms require two parties to come to agreement.
Because policies are anticipated to be applied by an AM "silently" (out of band) with respect to the UMA protocol, this is an opportunity for AM business value and we should not dictate any answers here. But following are some policies that could be useful:
By contrast, terms might take some of the following forms:
The following hypothetical wireframe (with hypothetical Creative Commons-like sets of standard terms) imagines what a user interface could look like for an AM's default policy and term settings for all resources it manages:
The UMA group is hoping to borrow from the work of others in using any standard sets of terms that might exist, for example as might be developed by the Kantara Information Sharing (UD-VPI) WG. However, even if this area is well fleshed out, major design questions remain.
Human interaction by a party "behind" the Requester
Some parties behind a Requester's actions may be big companies like credit card issuers, large e-commerce sites, or government agencies – but some may be small organizations, such as a dentist's office. Small organizations may need a human-accessible interface and the option of an "I Agree" button so that the person manually fielding an offer of data can complete the transaction.
Requester resistance to user-driven terms
It may be necessary for us to consider "partial measures" in the V1 UMA effort to improve adoption. For example, it may be more difficult to demand evidence of positive action (such as payment) from a Requester vs. demanding a simple statement of passive acceptance of terms (such as "I agree not to sell the data"). This would be a natural first step if Requesters are at all amenable to the notion of user-driven terms.
If we discover that Requesters are resistent, we may need to consider options for allowing the user to passively inform the Requester of policies such as "I ask you not to sell this data", rather than requiring action on the part of the Requester to accept such terms. Or given that Requesters are today in the habit of making their own terms of service and privacy policies known to users in passive fashion, we may need to account for a case where the user's terms amount to an opening gambit of "What can you offer me?" in a contract negotiation.
Depth of contract negotiation
There is some minimum functionality needed around a sequence roughly like the following:
However, there are many layers of sophistication we could get into, depending on where our scenarios take us. For example, is it important for the user to be able to specify "you must satisfy these terms 'or better'"? If so, what does "better" mean? Do we have to solve for "I will sell you n pieces of data for terms X, but n+m pieces for terms Y"?
Legal enforceability and terms persistence
We have discussed whether machine readability of terms is strictly needed, since having a URL that persistently refers to a human/lawyer-readable version seems to suffice in a lot of cases today for string-matched satisfaction (no complex negotiation), including very complex enterprise cases. Nat Sakimura's blog post on contract exchange suggests various ways to characterize, share, negotiate, and record data-sharing contracts. How we answer these questions also has an impact on our goals around simplicity, particularly our emerging goal around not adding undue cryptography burdens.
Paul Bryan has stated a preference expressing a set of terms as a Web resource whose representation can be retrieved with an HTTP GET and modified (with an affirmation that the terms are being met) with an HTTP POST.
Is this site useful to you? Please share it!
| | More
Pages in this Space:
You are viewing an old version of this page. View the current version. Compare with Current · View Page History