Abstract. A public-key cryptosystem is usually used for key management, in particular to session key management. The paper presents a method for handling a batch of concurrent keys with homomorphic publickey cryptosystems such as RSA, Paillier and ElGamal. Theorematically, regardless Shacham and Boneh proved that it is impossible to provide batch RSA encryption of messages with a single certificate, the present result is positive when the messages are small. Practically, the present method is compliant to the de facto standard SSL/TLS handshake and increases the SSL system performance.