(19)

(11)

EP 1 163 752 A1

(12)

(43) Date of publication: 19.12.2001 Bulletin 2001/51 (21) Application number: 00926087.8 (22) Date of filing: 17.04.2000

(51) International Patent Classification (IPC)7: H04K 1/00 (86) International application number: PCT/US0010/398 (87) International publication number: WO 0064/088 (26.10.2000 Gazette 2000/43)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE Designated Extension States: AL LT LV MK RO SI (30) Priority: 15.04.1999 US 129380 P (71) Applicant: Chaum, David Sherman-Oaks California 91403 (US)	(72) Inventor: Chaum, David Sherman-Oaks California 91403 (US) (74) Representative: Prins, Adrianus Willem et al Vereenigde, Nieuwe Parklaan 97 2587 BN Den Haag 2587 BN Den Haag (NL)