Scenarios such as online banking, mobile payment systems, stock trading, selling merchandise, and a host of other applications that need a high level of security have moved from the research domain to real world. Moreover, the nature of clients has been changing from traditional desktops to mobile and handheld devices. Protocols like SSL, SSH are the present standard for establishing secure channels. However, the drawback in these protocols is that both the server and the client need to perform computationally expensive public-key operations for secure channel establishment. In this paper, we present simple constructions that spread the cost of secure channel establishment over several sessions. Our constructions are incrementally deployable and can operate with existing protocols such as SSL and SSH. Experimental results indicate that our constructions are practical and efficient in reducing the computational load at the server as well as the client side. Key Words. Session Key Establ...