Owner Microsoft Corporation

Inventors Reasor, Sterling M.; Hutz, Benjamin A.; Perlin, Eric C.; Stephens, John; Richards, Stefan; Flo, Eric R.; Ilac, Cristian; Schutz, Klaus U.

Agent Davies Collison Cave

Pub. Number AU-B-2004220758

Priority 10693585 24.10.03 US

Filing date 29 September 2004

Wipo publication date 12 May 2005

Acceptance publication date 18 February 2010

G06F 21/20 (2006.01) Security arrangements for protecting computers or computer systems against unauthorised activity

G06F 21/00 (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

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