(19)

(11)

EP 4 208 979 A1

(12)

(43) Date of publication: 12.07.2023 Bulletin 2023/28 (21) Application number: 21865257.6 (22) Date of filing: 07.09.2021

(51) International Patent Classification (IPC):  H04L 9/08(2006.01) H04L 9/32(2006.01) H04L 9/30(2006.01) (52) Cooperative Patent Classification (CPC): H04L 9/50; H04L 9/3247; H04L 2209/42; H04L 2209/46; H04L 2209/56; H04L 2209/046; H04L 9/085 (86) International application number: PCT/US2021/049217 (87) International publication number: WO 2022/051706 (10.03.2022 Gazette 2022/10)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 06.09.2020 US 202063075193 P 10.08.2021 US 202117398255 (71) Applicant: Chaum, David Sherman Oaks, CA 91403 (US)	(72) Inventor: Chaum, David Sherman Oaks, CA 91403 (US) (74) Representative: IP Sextant s.r.l.  Via A. Salandra, n.18 00187 Rome 00187 Rome (IT)