SEAL: A secure communication library for building dynamic group key agreement applications

We present the SEcure communicAtion Library (SEAL) [source can be downloaded from: http://www.cse.cuhk.edu.hk/~cslui/ANSRlab/software/SEAL/], a Linux-based C language application programming interface (API) library that implements secure group key agreement algorithms that allow a communication group to periodically renew a common secret group key for secure and private communication. The group key agreement protocols satisfy several important characteristics: distributed property (i.e., no centralized key server is needed), collaborative property (i.e., every group member contributes to the group key), and dynamic property (i.e., group members can join or leave the group without impairing the efficiency of the group key generation). Using SEAL, we developed a testing tool termed Gauger to evaluate the performance of the group key agreement algorithms in both wired and wireless LANs according to different levels of membership dynamics. We show that our implementation achieves robustness when there are group members leaving the communication group in the middle of a rekeying operation. We also developed a secure chat-room application termed Chatter to illustrate the usage of SEAL. Our SEAL implementation demonstrates the effectiveness of group key agreement in real network settings.