A security architecture in which a security module is integrated in a client machine, wherein the client machine includes a local host that is untrusted. The security module performs encryption and decryption algorithms, authentication, and public key processing. The security module also includes separate key caches for key encryption keys and application keys. A security module can also interface a cryptographic accelerator through an application key cache. The security module can authorize a public key and an associated key server. That public key can subsequently be used to authorize additional key servers. Any of the authorized key servers can use their public keys to authorize the public keys of additional key servers. Secure authenticated communications can then transpire between the client and any of these key servers. Such a connection is created by a secure handshake process that takes place between the client and the key server. A time value can be sent from the key server to the client, allowing for secure revocation of keys. In addition, secure configuration messages can be sent to the security module.