Abstract
M.Sc.
The aim of this dissertation (referred to as thesis in the rest of the document) is to investigate the concept of Single Sign-on (SSO) in heterogeneous computing environments and to provide guidelines and reference frameworks for the selection and successful implementation of SSO solutions. In doing so. it also provides an overview of the basic types of SSO, Secure Single Sign-on (SSSO) solutions, enabling technologies, as well as products currently available.
Chapter 1 introduces the sign-on problem, the purpose and organization of the thesis and terminology and abbreviations used. The crux of the sign-on problem is that users are required to sign on to multiple systems, developed at different times and based on different technologies, each with its own set of signon procedures and passwords. This inevitably leads to frustration, loss of productivity and weakened security. Users frequently resort to writing down passwords or using trivial password that can easily be guessed.
In Chapter 2 the concepts of Single Sign-on and a special subset of SSO, Secure Single Sign-on are defined. Five types of SSO solutions are identified, namely: Synchronization, Scripting, Proxies and Trusted Hosts. Trusted Authentication Server and Hybrid solutions. Of the available types of solutions, only Trusted Authentication Server and Hybrid solutions can provide Secure Single Sign-on if properly implemented. The security services for SSSO are identified as authentication, authorization, integrity, confidentiality, non-repudiation, security management and cryptographic services. Additional SSSO concepts, as well as the vulnerabilities, obstacles and pitfalls to introducing SSO solutions are discussed.
Chapter 3 provides an overview of the most important SSO enabling technologies. The following technologies are discussed: OSF DCE, SESAME, Kerberos, DSSA/SPX, TESS, NetSp, Secure Tokens, GSS-API and Public key Cryptography.
Chapter 4 discusses the Open Software Foundation's (OSF) Distributed Computing Environment (DCE). OSF DCE is one of the two open standards for distributed processing which are having a major influence on the development of single sign-on solutions and forms the basis of many existing SSO products. DCE is not a SSO product. but consists of specifications and software. The goal of DCE is to turn a computer network into a single, coherent computing engine. It is considered to be one of the fundamental building blocks for SSO solutions in the future.
In Chapter 5 SESAME is discussed in some detail as another major enabling technology for SSO. Secure European System for Applications in a Multi-vendor Environment (SESAME) is an architecture that implements a model for the provision of security services within open systems developed by the European Computer Manufacturers Association (ECMA). The architecture was developed and implemented on a trial basis, by Bull, ICL and Siemens-Nixdorf in an initiative supported by the European Commission.
Chapter 6 presents a list of 49 commercial SSO products currently available, classified according to the type of SSO solution. A few representative products are discussed in more detail to give an indication what functionality a prospective buyer could expect.
The 'Ideal Single Sign-on' solution is presented in Chapter 7. Detailed requirements are listed. These requirements are uniquely identified by a code and classified as essential or recommended functionality required.
Chapter 8 assimilates the information in the previous chapters into a structured evaluation, selection and implementation plan for SSO solutions, consisting of nine separate phases. It also proposes a reference framework for the evaluation and selection process. Chapter 9 concludes the thesis. Findings and conclusions are summarized as to the importance and impact of Single Sign-on as well as the expected future directions to be expected. In addition, recommendations for the future implementation of SSO and SSSO solutions in heterogeneous computing environments are made.