Some cryptographic techniques for machine-to-machine data communications

Some of the threats to the integrity of multiuser teleprocessing systems and to the data they contain can be countered by the use of cryptography. Stream-generator ciphers are not ideally suited for such an application, thus the use of block ciphers, which have the beneficial property of a strong nonlinear intersymbol dependence, is suggested. This property provides the means for automatic error detection for verifying the authenticity of terminal operators, and for ensuring messase integrity. An experimental demonstration system has been constructed to illustrate protection features that can be provided for real applications.