Improved LKH for batch rekeying in multicast groups

Storage, delivery and update of cryptographic keys are the most important items to study in multicast security. Traditionally a centralized trusted third party called the key server (KS) performs these actions. Different works have been presented that address the issue of minimizing storage for KS and required bandwidth for updating keys. Our research group has been working in a method for multicast rekeying using a broadcast encryption technique and pseudo-random functions in order to reduce number of sent messages for rekeying and minimize the number of keys to store by the KS. We apply this technique to batch rekeying and present performance evaluation for different benchmark scenarios. We conclude that the technique is suitable for group joining and leaving and in some cases performs better behavior than other existing methods.