Managing secure communications with multilevel security and restricted character set translation

It has been shown that a source file can be translated using a restricted character set. US Naval message traffic is transmitted with a restricted character set, and the files are optionally compressed. Both character translation and data compression can be used as add-on data encryption. Various schemes of restricted character set translation have been investigated and their implementations on computers are discussed. Translation algorithms that use a restricted character set have been implemented with multilevel security access control using the master key scheme and have been incorporated in a data compression program for military applications. Although the key management scheme discussed is perfectly feasible, it is by no means the single or best possibility. The method used here allows only for the availability of different keys for different links and hosts, but does not differentiate the different functions or activities for which the keys are used. The functions stressed in this study are data compression and character translation