The applications of quantum cryptography are linked to telecommunication services that require very high level of security. Quantum cryptography could be integrated in various existing concepts and protocols to secure communications. One of the possible use of quantum cryptography is within IPSEC or IPv6. The aim of this paper is to analyse the use of quantum cryptography within IPSEC to secure communications and to present the estimated performances of this solution. In this paper, we introduce basic concepts in quantum cryptography, we propose a solution that integrate quantum key distribution into IPSEC. A performance analysis is done to demonstrate the operational feasibility of this solution.