STATISTICAL DISTRIBUTION OF DELTA MODULATED SPEECH SIGNALS AS A MEANS FOR CRYPTANALYSIS IN VOICE ENCRYPTION SYSTEMS
Anastasios Kourtis, Ch. Mantakas · Cryptologia · 1998
This paper shows that the probability distribution function of the byte values resulted from the segmentation of bits in a delta-modulated speech signal has a certain shape which is independent of the speaker or the language. This shape can be used as a criterion for the distinction of digital plain speech from encrypted for cryptanalysis purposes in delta modulation voice encryption systems.