"IBM Research has demonstrated Linux running on the IBM
4758 secure cryptographic coprocessor, a hardware security module.
This is the first general purpose operating system (OS) running on
a secure coprocessor. The IBM 4758 cryptographic coprocessor is an
advanced, tamper-sensing and responding, programmable PCI card. Its
specialized cryptographic electronics, along with a microprocessor,
memory and random number generator are housed within a
tamper-responding environment to provide a highly secure subsystem
in which data processing and cryptography can be performed.
By running Linux, it enables much easier migration and porting
of applications into the secure environment than with the current
CP/Q operating system. As a key product for secure e-business, its
main applications are financial-related solutions, such as
electronic coupon dispensers, Internet postage meters, intellectual
property protection (web subscription services), signatures for
digital documents and certificate authorities.
The Linux-based IBM 4758 also offers significantly better
performance, including eight times improved communication latency
and four times faster throughput, over the current custom OS based
product offering. In addition, Linux provides better support for
new features, which are not supported by the custom OS such as
running multiple potentially hostile applications on the same 4758
coprocessor card and allowing cross card communications that
enables load balancing among multiple cards."