Abstract: A system and method for performing secure peer-to-peer device communications on an I/O bus, such as a PCI bus, a Fiber Channel bus, an IEEE, 1394 bus or a Universal Serial Bus. The system includes a plurality of intelligent I/O devices, such as intelligent storage devices and/or controllers, communications devices, video devices and audio devices. The I/O devices perform peer-to-peer message and data transfers, thereby bypassing the operating system running on the computer's CPU. The intelligent I/O devices encrypt messages and data before transmitting them on the I/O bus and conversely decrypt the messages and data upon reception. The encryption provides secrecy and/or authentication of the sender. The devices use keys or passwords to encrypt/decrypt the data. The keys are stored in non-volatile memory in the devices and are distributed to the devices by the system BIOS at initialization time.