CRYPTOGRAPHIC MODELS FOR COMPUTER COMMUNICATIONS (ALGEBRAIC-CODED ENCRYPTION, RESIDUE-CODED, DBMS, ERROR-CONTROL CODES, CRYPTO-COMPLEXITY)

With increasing data volumes accessed and computations performed interactively via physically unsecured and noisy communication channels, the problems involving data security and reliability for computer communication become increasingly important.; Conventional data security has been provided by operating system and/or physical controls. The communication security and reliability are provided by data encryption and error-control coding respectively.; The concept of JOint Encryption and Error-control Coding (JOEEC) was introduced previously to combine data encryption and error-control coding into one step to gain speed and efficiency for both data communication security and reliability.; The goal of this research is to establish that Algebraic Codes (including Residue Codes) can be used to provide both security and reliability with low encryption-decryption overhead and can be efficiently implemented for computer communication. A new approach to the private-key algebraic-coded cryptosystems which allows the use of very simple codes such as distance 3 and 4 Hamming codes has been developed in this research. Also, a residue-coded cryptosystem with a method different from the DWK cryptosystem has been suggested for efficient implementation of computer communication and data processing in database management systems.