VERFAHREN ZUR DATENSICHERUNG IN EINEM PAY-TV- SYSTEM UNTER VERWENDUNG EINES KRYPTOSYSTEMS MIT ÖFFENTLICHEM SCHLÜSSEL

摘要

For data security in a pay-TV system, a public key is in each case determined from a secret key which is allocated by the programme provider to the pay-TV receiver and which is used in the programme distribution centre to encrypt secondary-key information in order to adapt the pay-TV receiver to repeatedly modified modes of transmission which are provided in the programme distribution centre for the pay-TV receiver. The programme provider can define new keys from time to time. The initial settings of scramblers and descramblers can be modified as modes of transmission.