Reducing Timing Channels with Fuzzy Time

This paper describes fuzzy time. This is a collection of techniques that reduces the bandwidths of covert timing channels by making all clocks available to a process noisy. Developed in response to the problems posed by high-speed hardware timing channels, fuzzy time has been implemented in the VAX security kernel. The VAX security kernel is a virtual-machine monitor security kernel for the VAX architecture designed to meet the requirements of the Al rating from the National Computer Security Center.

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