I am using a Key Distributed Center (KDC) and a key distribution protocol such as Kerberos. In order to limit the amount of ciphertext produced with the same key, I want to renew the session keys every 2 minutes. However, for performance reasons I only want to involve the KDC once per hour.
I thought about extending this protocol by making use of the Diffie-Hellman key exchange but this would require generating a new alpha and a prime number each time which is quite expensive, considering it has to be carried out once every two minutes.
Any suggestion how I can extend this protocol in an efficient way please?