SMSAuthenticator

From the developer: ""SMSAuthenticator is an open source authentication module for situations where 'username and password'-login provide insufficient security. The additional security is achieved by sending keys (single-use passwords) by SMS to the user's mobile phone. SMSAuthenticator solves some of the main problems with ordinary passwords (for instance password guessing and password sniffing) without requiring special hardware on the user's side. Being SOAP-based, the SMSAuthenticator may be easily integrated into existing environments, requiring only a SOAP client library in the consumer application.""

Requirements:

Windows NT/2000/XP, Java Runtime Environment 1.2, JDBC database