초록 ▼

A decoder conditional access system incorporates different encryption systems for providing access to programs derived from different sources. A conditional access processor for processing encrypted program data and an associated encryption code includes a first algorithm means for decrypting the en

A decoder conditional access system incorporates different encryption systems for providing access to programs derived from different sources. A conditional access processor for processing encrypted program data and an associated encryption code includes a first algorithm means for decrypting the encryption code to provide an encryption key. The conditional access processor also includes a second algorithm means for encrypting the encryption key and the second encryption algorithm is different to the first encryption algorithm. A datastream representing the program is generated from encrypted program data and an associated encryption code. The encryption code is decrypted to provide an encryption key using a first algorithm. The encryption key is encrypted using a second algorithm different to the first encryption algorithm and the program datastream is formed from the encrypted program data and the encrypted encryption key. The program datastream is decrypted by selecting betweena first and a second decryption algorithm and by decrypting the encryption code to provide an encryption key. The encryption key is used to decrypt the encrypted program. A storage medium data format for recording encrypted program data is also disclosed.

대표청구항 ▼

[ What is claimed is:] [1.] A conditional access processor for processing a digital datastream containing encrypted program data and an encryption code, comprising:first algorithm means for decrypting said encryption code to provide an encryption key; andsecond algorithm means for encrypting said en

[ What is claimed is:] [1.] A conditional access processor for processing a digital datastream containing encrypted program data and an encryption code, comprising:first algorithm means for decrypting said encryption code to provide an encryption key; andsecond algorithm means for encrypting said encryption key, whereinsaid second encryption algorithm is different from said first encryption algorithm whereinsaid conditional access system resides within a host device;said first and second algorithms are contained in an electronic device employed within said conditional access system; andsaid electronic device is insertable into said host device.