M.Sc.

Abstract : The work reported in this thesis deals with the performability evaluation of the Token Ring Network. Performability evaluation arose from the need to determine overall quality of service by relating and quantifying aspects of what a specific system is and does (how well it performs) with respect to what the system is required to be and to do (how its functionality is affected by faults). Performability is a term used to describe performance and reliability. Performance is defined as _quality of service provided the system is correct_.

Abstract : A Smart Card is the latest addition in the world of information technology. It has an electronic microchip embedded in it. The chip stores electronic data and programs that are protected by advanced security features. The Smart Card brings a variety of benefits to users. Smart Cards are used all over the world as personal identification cards for corporate building security systems and PC equipment access control. Smart Cards are used as Credit or Debit cards.