Date Added: Jun 2010
Secure communication is a basis for most digital operations that are performed nowadays. The need is especially emphasized in a distributed environment. A proper authentication mechanism is the very basic requirement for building a secure environment. A lot of effort has been invested in development of various types of authentication mechanisms that offer strong security characteristics for building grid systems. Being based on one of the mechanisms, most grid environments today provide strong authentication protocols. However, they are usually bound with only one, in most cases based on public key infrastructure. Such arrangement works well, but unnecessarily limits users since they are required to use only the one mechanism, which may not be flexible or convenient. Asymmetric cryptography allows for efficient key management, in loosely coupled distributed environment. The concept of two separated keys has been proven to provide a scalable solution to parties that need to mutually communicate and do not share any pre-distributed secret. As the simplest implementation of asymmetric cryptography, a plain key-pair can be used to establish an authentication connection. This approach is employed by the popular ssh protocol, where such a simple public key based authentication is mandatory to implement and widely used. While it is convenient for users, having authentication based only on lain keys is not sufficient and is hard to maintain in a large environment.