Pepe Compra El Calefón

Authentication, Authorization and Accounting
in Ad Hoc networks

26th of May 2000
Sami Levijoki
Department of Computer Science
Helsinki University of Technology
slevijok@cc.hut.fi

http://www.tml.hut.fi/Opinnot/Tik-110.551/2000/papers/
http://www.tml.hut.fi/Opinnot/Tik-110.551/2000/papers/authentication/aaa.htm


Abstract
Authentication, Authorization and Accounting (AAA)functionality is needed frequently in many network services. Typically authentication, authorization, and accounting are more or less dependent on each other. However, separate protocols are used to achieve the AAA functionality. IETF AAA working group is trying to design one AAA protocol that could be used in a variety of applications. AAAARCH is also trying to build a general architecture for AAA systems.Mobile Ad Hoc networking (MANET) brings new challenges to providing the AAA functionality. Ad Hoc networks are by their nature rapidly changing and dynamic. There isn't necessarily any network infrastructure present. These and other features of Ad Hoc networks present many new requirements for the protocols that are to be used in Ad Hoc networks.--------------------------------------------------------------------------------

Contents
1 Introduction
2 AAA overview
2.1 General description of AAA systems
2.2 Generic AAA architecture
3 Requirements for AAA protocols
3.1 Authentication requirements
3.2 Authorization requirements
3.3 Accounting requirements
3.4 Scaling and reliability of accounting
4 Existing protocols
4.1 RADIUS
4.2 DIAMETER4.3 ISAKMP/IKE
4.4 SASL
4.5 PolicyMaker
4.6 KeyNote2
5 AAA in combination with Mobile IP
5.1 General
5.2 Architecture
6 AAA in Ad Hoc networks
6.1 Threat and problems
6.2 Authentication
6.3 Authorization
6.4 Accounting
6.5 AAA systems
7 Conclusions
References

1 Introduction
Today we live in a world where almost everything must beprotected from misuse and where nothing is free. When providing commercial network services to public, there are three things that are commonly needed. These are authentication, authorization and accounting. Authentication is needed to make sure that the user of the service is who he claims to be. This is quite important, because you don't want that someone else is using the service you have paid for.Usually authentication is provided by using a shared secret or a trusted third party. Related to authentication is authorization. After the user has been authenticated we need a way to ensure that the user is authorized to do the things he is requesting. For example, if you are a normal user you don't have the permissions to access all the files in a file system. Usually authorization is providedby using access control lists or policies. Accounting is the process in which the network service provider collects information of the network usage for billing, capacity planning and other purposes. This is important for the service provider, because there is no such thing as a free lunch.
There is a growing need to transfer data between different kind of devices that are close to each other.There might not be any kind of wired networking service available to achieve this and even if there would be it is not always a very easy way to transfer the data. So it would be reasonable for the devices to be able to communicate with each others while they are within range. Ad hoc networking tries to solve this problem. An Ad hoc network is a dynamically changing network that is created by themobile nodes when needed for their own communication purposes. The mobile nodes can act as routers between the entities in the network. In an ad hoc network mobile nodes can come and go as they wish, so the topology of the network is changing quite rapidly. This creates new challenges for the protocols that are to be used in the ad hoc networks. Most of the traditional protocols don't fit very...