Introduction

The research in security has delivered many security protocols at the link layer to provide authentication, data encryption and integrity. Popular security solutions for Wireless LANs today include 802.1x  and WEP  that provide fixed security mechanisms. We designed Adaptive Link Layer Security (ALL-Sec) architecture for wireless networks in which different security components can be adaptively integrated to provide value-added security services to diverse users. A security mechanism is a composition of individual security components (e.g., confidentiality, authentication,  integrity, key distribution) at link layer of the network stack depending on various environmental factors. ALL-Sec attempts to leverage existing security components in the most efficient manner to usher a new way of security service provision. The major contribution of the proposed ALL-Sec framework, making our approach unique, is the adaptive composition of existing security components which provide users with their required security services while adapting to 1) the mobile and changing nature of wireless networks, 2) heterogeneous devices that may be used simultaneously for data communication, 3) dynamically changing client resources and 4) diverse user preferences. None of the solutions proposed so far allowed for adaptive composition of the security components at runtime and hence, unable to provide efficient security services in a dynamic wireless environment. Our design is flexible enough to take on changes that may need to be incorporated in the future.