INFORMATION CIPHERING METHOD, INFORMATION DECIPHERING METHOD, INFORMATION CIPHERING DEVICE, INFORMATION DECIPHERING DEVICE AND INFORMATION RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an information ciphering method by which a ciphering and a deciphering are relatively simply and inexpensively enabled and the estimation of a deciphering key is made difficult. SOLUTION: An information control means 1 accumulates information key codes peculiar to digital information and information signals. A customer control means 5 accumulates customer peculiar certifying keys and reproducing device peculiar distribution keys. Then, a code conversion means 9a converts the information key codes and generates work key codes. An information ciphering means 11a generates ciphering key codes from the work key codes and the sector numbers outputted from the means 9a. Then, the sectored digital information data are ciphered by using the ciphered key codes.