Method to maximize hardware utilization in flow-thru IPsec processing

The invention relates to a network interface system for interfacing a host system with a network. The network interface system includes a bus interface system, a media access control system, a memory system, and a security system. The security system is coupled to the memory system and is adapted to selectively perform security processing on incoming and outgoing data. For at least one of receive or transmit processing, the security system comprises one or more encryption pipelines and at least two sets of one or more authentication pipelines. The encryption pipelines are adapted to perform one or more encryption or decryption algorithms. The authentication pipelines are adapted to perform one or more authentication algorithms. The security system is configured to selectively process frames through the encryption pipelines and then through the two sets of authentication pipelines. The system toggles whereby successive frames alternate between the two sets of authentication pipelines.