A method for efficiently decrypting asymmetric SSL pre-master keys is divided into a key agent component that runs in user mode, and an SSL driver running in kernel mode. The key agent can take advantage of multiple threads for decoding keys in a multi-processor environment, while the SSL driver handles the task of symmetric decryption of the SSL encrypted data stream. The method is of advantage in applications such as firewalls with deep packet inspection in which all encrypted data traffic passing through the firewall must be decrypted for inspection.