Trust Relations in a Digital Signature System Based on a Smart Card

In this paper we present different ways for an attacker to tamper with a digital signature scheme. The paper focuses on smartcard-based signature schemes because they offer the best ratio of cost over security. The risks of compromise or attack for each part of the system used to produce the signature are assessed and possible solutions for the problems illustrated are suggested. In fact, the smartcard is often the most secure link in the chain of trust involved in digital signature systems