(19)

(11)

EP 1 769 620 A2

(12)

(88) Date of publication A3: 15.06.2006 (43) Date of publication: 04.04.2007 Bulletin 2007/14 (21) Application number: 05755600.3 (22) Date of filing: 28.06.2005

(51) International Patent Classification (IPC):  H04L 29/08(2006.01) (86) International application number: PCT/GB2005/002509 (87) International publication number: WO 2006/000802 (05.01.2006 Gazette 2006/01)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR (30) Priority: 28.06.2004 GB 0414415 (71) Applicant: Amteus Secure Communications Limited Leeds West Yorkshire LS4 2LE (GB)	(72) Inventors: Morris, Jeffrey Leeds, West Yourkshire LS4 2LE (GB) Foot, Eric Leeds, West Yourkshire LS4 2LE (GB) Barr, Robert Leeds, West Yourkshire LS4 2LE (GB) Warburton, Ranald Leeds, West Yourkshire LS4 2LE (GB) (74) Representative: Ahmad, Sheikh Shakeel et al David Keltie Associates Fleet Place House 2 Fleet Place London EC4M 7ET London EC4M 7ET (GB)