Digital video recorder employing a file system encrypted using a pseudo-random sequence generated from a unique id

Abstract

A digital video recorder (DVR) is disclosed comprising a unique ID, a hard disk drive (HDD) for storing a plurality of encrypted video programs and an encrypted file system, the encrypted file system comprising a plurality of encrypted file system entries for decrypting the plurality of video programs. The DVR further comprises host circuitry for interfacing with the HDD, the host circuitry comprising a cryptography facility for encrypting plaintext file system entries into the encrypted file system entries stored on the HDD, and for decrypting the encrypted file system entries read from the HDD into plaintext file system entries. The cryptography facility comprises a pseudo-random sequence generator, responsive to the unique ID, for generating a pseudo-random sequence. The cryptography facility further comprises an encoder for combining the pseudo-random sequence with the plaintext file system entries to generate the encrypted file system entries stored on the HDD, and a decoder for combining the pseudo-random sequence with the encrypted file system entries read from the HDD to generate the plaintext file system entries.