Coding and cryptography for speech and vision

Abstract

There are many areas of industry in which coding and cryptography play a key role, and in this paper applications to speech, video and data communications are described. In each case, the purpose of the coding and encryption processes is to improve the reliability, privacy and integrity of information transmission over different media, including telephone lines, mobile radio and satellites. Coding for error correction is often preceded by source coding and data compression techniques, and it is therefore inevitable that the applied error protection coding and cryptographic techniques depend on the nature of the signals to be transmitted. This is illustrated in our paper by considering the following application areas: compression and security of speech transmissions; transmission of still video pictures in a matter of a few seconds over voice band radio; and security for mobile telecommunications systems.