Owner Sony Corporation

Inventors Sako, Yoichiro; Furukawa, Shunsuke; Inokuchi, Tatsuya

Agent Griffith Hack

Pub. Number AU-B-2002235551

PCT Pub. Number WO02/54666

Priority 2000-403467 28.12.00 JP; 2001-163126 30.05.01 JP

Filing date 27 December 2001

Wipo publication date 16 July 2002

Acceptance publication date 15 March 2007

G06F 12/14 (2006.01) Accessing, addressing or allocating within memory systems or architectures - Protection against unauthorised use of memory

G06F 21/24 (2006.01) Security arrangements for protecting computers or computer systems against unauthorised activity

G09C 1/00 (2006.01) Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a predetermined system

G09C 5/00 (2006.01) Ciphering or deciphering apparatus or methods not provided for in other groups of this subclass, e.g. involving the concealment or deformation of graphic data such as designs, written or printed messages

G11B 20/00 (2006.01) Signal processing not specific to the method of recording or reproducing

G11B 20/10 (2006.01) Signal processing not specific to the method of recording or reproducing - Digital recording or reproducing

H04L 9/08 (2006.01) Arrangements for secret or secure communication - Key distribution

H04L 9/32 (2006.01) Arrangements for secret or secure communication - including means for verifying the identity or authority of a user of the system

H04N 5/00 (2006.01) Details of television systems

H04N 5/913 (2006.01) Details of television systems - for scrambling

H04N 7/16 (2006.01) Television systems - Secrecy systems

H04N 7/167 (2006.01) Television systems - Systems rendering the television signal unintelligible and subsequently intelligible