Simple timing channels

We discuss the different ways of defining channel capacity for certain types of illicit communication channels. We also correct some errors from the literature, offer new proofs of some historical results, and give bounds for channel capacity. Special function techniques are employed to express the results in closed form. We are interested in a specific type of covert channel, a timing channel. A timing channel exists if it is possible for High to interfere with the system response time to an input by Low. Therefore, a timing channel is a communication channel where the output alphabet is constructed from different time values. However, the thrust of the paper is the analysis of timing channels that are discrete, memoryless, and noiseless. We call such a timing channel a simple timing channel (STC)