A system and method for securely communicating with a destination server over a network in accordance with a protocol that, at least optionally, provides client authentication. The system comprises a client and an intermediate server that is adapted to establish a secure connection with the destination server on behalf of the client. When the destination server requires a digital signature that has been generated using a private key associated with the client in order to authenticate the client, the intermediate server provides the client with the data to be signed using the private key. If the client returns the requisite digital signature to the intermediate server, then the intermediate server will transmit the digital signature to the destination server.