Abstract. Biometric systems are widely applied since they offer inherent advantages over traditional knowledge-based and token-based personal authentication approaches. This has led to the development of palmprint systems and their use in several real applications. Biometric systems are not, however, invulnerable. The potential attacks including replay and brute-force attacks have to be analyzed before they are massively deployed in real applications. With this in mind, this paper will consider brute-force break-ins directed against palmprint verification systems.