An Encryption and Authentification Procedure for Telesurveillance Systems.

To perform message authentication in a telesurveillance system, the paper proposes a non linear time varying encryption algorithm, based on key layering in three levels (system key, intermediate key, running key) and on encryption organization into two or more sets of three operations (running key rotation, message digit substitution and transposition). The algorithm was designed to be implemented on an 8-bit microprocessor. [ABSTRACT FROM AUTHOR]