SCDJWS Study Guide: Web Service in General
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Federation Management
Consider the many times an individual accesses services on the Internet
in a single day. One person might have a multitude of accounts set up
to access various business, community and personal service providers;
for example, the person might have used different names, user IDs,
passwords or preferences to set up accounts for a news portal, a bank,
a retailer, and an email provider. Each time he accesses a service on
the Internet, he must log in and identify himself to the service
provider.
Federation allows for the interchange of
security-related information
between different entities. Security-related information meaning:
authentication, authorization, and auditing data. Although federation
is generally used in the context of an inter-enterprise security
mechanism, it can also be used within an enterprise, to provide tighter
integration between several loosely-coupled ecosystems. A federation
agreement always deals with two entities:
- An asserting party that generates security assertions, and
- A relying party that trusts the security assertion made by the asserting party
What Is Identity?
In today's information systems, not only people have identities in our
network,
but also organizations, computers, devices, and systems or
applications
have identities. Identity is
a set of attributes that describes a
profile
of an individual, business organization, or software entity. Identity
verification
is a dialog of presentation and interpretation.
The designers of kerberos understood this concept when they created a
mechanism
for authenticating not just users, but also machines. Every computer
system,
every application system and by extension every user within an
enterprise
have a unique identity and fall into some logical grouping.
A local identity
refers to the set of attributes or information that identify a user to
a particular service provider.
These attributes uniquely identify the individual with that provider.
For uniquely identify a person, the attributes can include a name,
phone number, passwords, social security number, address, credit
records, or other identifier. For example, the individual in our
scenario is known to his company's network as an employee number, but
he is known to his travel agent as Joe Smith. He is known to his online
news service by an account number, and he is known to his favorite
clothing store by a different account number. He uses one email name
and address for his personal email, and a different email name and
address for his workplace. Each of these different user names
represents a different local identity.
Because the Internet is fast becoming the prime
vehicle for business, community and personal interactions, it has
become necessary to fashion a system for online users to link their
local identities, enabling them to have one network
identity. This system is identity federation.
What Is Identity Federation?
Identity federation allows a user to associate,
connect or bind the local identities configured with multiple service
providers. A federated identity allows users to login at one service
provider’s site and move to an affiliated service provider site without
having to re-authenticate or re-establish their identity.
It combines data on a single user from multiple sources, for purposes such as authorization. Since different organizations probably want to use different products to manage the identity data they have, standards are needed to move that data around the network—from where it is being held to where it will be used. The Liberty Alliance Project addresses these challenges.
Identity Management Architecture
An identity management system mediates between identities and
resources:
it controls identity resource access and facilitates identity resource
access
management. There are two possible identity management architectures,
one
based on a centralized model and the other, on a federated model.
- In the centralized model, a single operator performs authentication and authorization by owning and controlling all the identity information.
Advantages of the Centralized Model:
- A single operator owns and controls everything, constructing and managing the identity network could be easier than with the federated model.
Disadvantage of the Centralized Model:
- The dangerous potential for the single operator becoming a tollgate for all transactions over the Internet. For example, the operator might charge a fee for every transaction you make. You might have to pay a few cents or dollars whenever you perform a transaction on eBay.
- A single operator could represent a single point of security failure or hacker attack.
- A single operator can take away the most important business asset—that is, customer identity and profile information—from an organization. That results in a serious threat to businesses such as banks and brokerage houses whose success depends on their customer information.
- In the federated model, both authentication and authorization tasks are distributed among federated communities.
The federated model, driven by the Liberty Alliance Project, is
designed
to correct the centralized model's problems. The goal of the
Liberty
Alliance
Project is to create an open standard for identity, authentication, and
authorization,
which will lower e-commerce costs and accelerate organizations'
commercial
opportunities, while at the same time increasing customer satisfaction.
In
a Liberty architecture, organizations can maintain their own
customer/employee
data while sharing identity data with partners based on their business
objectives
and customer preferences.
In the federated identity management architecture scheme, three roles
could exist:
- Consumer
Consumer can have multiple identity profiles, and you can ask different identity providers to maintain these profiles. For example, you might want your HMO to manage your healthcare profile and your brokerage house to maintain your brokerage profile. In fact, as a consumer, you can pick and choose which identity provider to maintain your profile based on price, credibility, service, and so on. In this model, consumers have a final say in terms of who can access what information. Consumers can be a person, a business, or a software entity.
- Identity Provider
Identity providers are service providers that specialize in providing authentication services. As the administrating service for authentication, they also maintain and manage identity information. Authentication accomplished by an Identity Provider is honored by all service providers with whom it is affiliated. Identity providers maintain user profile information and can interoperate among themselves as long as they have permission to do so from the profile's owner, the consumer.
- Service Provider
Service providers are commercial or not-for-profit organizations that offer web-based services. This broad category can include internet portals, retailers, transportation providers, financial institutions, entertainment companies, libraries, universities, and governmental agencies. Service providers can customize their services to each consumer by retrieving relevant identity profiles from the identity providers.
In the phase with no federation (separate login for each site), a
consumer must log in separately to each site. This phase will then
evolve into an
environment where multiple identity networks exist. Within a single
identity
network, single sign-on can be achieved. However, no network-to-network
identity
propagation is available at this stage. Eventually, these individually
constructed
and operating identity networks will work together by exchanging their
consumers' identity information, thus providing a truly seamless,
global-scale identity network, the Liberty Alliance Project's ultimate
goal.
The ATM network serves as an analogy for the federated network.
Initially, individual banks issued their own ATM cards, and different
banks did not
interoperate. At this stage, you could not use your ATM card in an ATM
machine
owned and operated by another bank. These days, you can use your credit
card
or ATM card in any ATM machine, as long as the bank that owns the
machine
and your bank are members of the same affiliation network. In the not
too
distant future, it is not a stretch to think about a single global
network
to which all banks directly or indirectly belong. The identity network
should
evolve similarly. One possible challenge of the federated identity
network
model is that because there are many parties involved, the standard has
to
be defined in an unambiguous manner. The Liberty Alliance Project
addresses
that challenge.
A federated identity refers
to the amalgamation of the account information in all service providers
accessed by one user (personal data, authentication information, buying
habits and history, shopping preferences, etc.). The information is
administered by the user yet, with the user’s consent, their privilege
to access information is securely shared with their providers of
choice. Federated Identity
allows users to link identity information between
accounts without centrally storing personal information. Also, the user
can control when and how their accounts and attributes are linked and
shared between
domains and service providers,
allowing for greater control over their
personal
data. In practice, this means that users can be authenticated by one
company
or website and be recognized and delivered personalized content and
services in other locations without having to re-authenticate or sign
on with a separate username and password.
The Liberty Alliance Project
The goal of the Liberty Alliance Project is to enable individuals and
organizations to easily conduct network transactions while protecting
the individual’s identity. To accomplish this, the Alliance has
established specifications for identity federation that enables:
- Opt-in account linking where users can choose to federate different service provider accounts.
- Single sign-on where a user can log in, authenticate to one service provider and gain access to other service providers with which they have federated without having to log in again.
- Authentication context where service providers with federated accounts communicate the type and level of authentication that should be used when the user logs in.
- Global log-out where a user logs out of an identity or service provider site and is automatically logged out of all sites that maintain a live session.
- Account linking termination where users can choose to stop their account federation.
These capabilities can be achieved when commercial or non-commercial
organizations join together into a circle of trust based on
Liberty-enabled technology and operational agreements. This circle of
trust includes service providers (who offer web-based services to
users), identity providers (service providers that also maintian and
manage identity information), and the users themselves. Once a circle
of trust is established between providers, users can choose to federate
any or all identities they might have with the service providers that
have joined this circle, enabling them to make use of the federated
authentication capabilities.
The summary the goal of Liberty Alliance Project are : To allow
individual consumers and businesses to maintain personal information
securely. o provide a universal open standard for single sign-on with
decentralized authentication and open authorization from multiple
providers. To provide an open standard for network identity spanning
all network devices.
Circle of Trust
The goal of the Liberty Alliance Project is to enable individuals and
organizations to easily conduct network transactions while protecting
the individual's identity. This goal can be achieved only when
commercial and non-commercial organizations join together into a circle
of trust.
A Circle of Trust is enabled through federated identity and is
defined
by the alliance as "a group of service providers that share linked
identities and have
pertinent business agreements in place regarding how to do business and
interact with identities. Once a user has been authenticated by a
Circle of Trust identity provider, that individual can be easily
recognized and take part in targeted services from other service
providers within that Circle of Trust. It should be noted that this
concept of trust-based relationships between organizations and their
individual or joint customers has existed in the offline business world
for years; two common examples would include travel alliances and
affiliate business partnerships."
A circle of trust is a federation of service providers linked together
by business relationships. The providers within the circle of trust
have operational agreements and sufficient infrastructure in place such
that customers can transact business with any or all of these service
providers within a secure and apparently seamless environment.
A trusted provider is a
generic term for one of a group of service and identity providers in an
Circle Of Trust. Users can transact and communicate with Trusted
Providers in a secure environment.
Reference
Secure Web services at
http://www.javaworld.com/javaworld/jw-03-2003/jw-0321-wssecurity.html
http://docs.sun.com/source/817-7643/5_federation.html
http://docs.sun.com/source/816-6774-10/prog_federation.html