Method and apparatus for en-bloc verification of plural digital signatures and recording medium with the method recorded thereon

US6212637A · kind A · utility

Assignee

• NIPPON TELEGRAPH AND TELEPHONE CORPORATION · JP

Inventors

• Kazuo Ohta · Zushi, JP
• Tatsuaki Okamoto · Musashino, JP

Key dates

• Filing date: Jun 25, 1998
• Grant date: Apr 3, 2001
• Expiry date: Jun 25, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L9/3247
• WIPO field: Digital communication
• WIPO sector: Electrical engineering

Abstract

Upon receiving a message {ID'.sub.i-1, X'.sub.i-1, m'.sub.i-1, Y.sub.i-1 } from a signer (i-1), a signer .sub.i generates a random number r.sub.i, then calculates X.sub.i =g.sup.r.sup..sub.i mod p using pieces of public information p, q and g, then sets X'.sub.i =(X'.sub.i-1, X.sub.i), m'.sub.i =(m'.sub.i-1, m.sub.i), then calculates e.sub.i =f.sub.i (X'.sub.i, m'.sub.i), d.sub.i =h.sub.i (X'.sub.i, m'.sub.i) with public one-way functions f.sub.i and h.sub.i, calculates y.sub.i =(y.sub.i-1 +d.sub.i r.sub.i +e.sub.i s.sub.i) mod q using a secret random number s.sub.i, sets ID'.sub.i =(ID'.sub.i-1, ID.sub.i), and sends information {ID'.sub.i,X'.sub.i,m'.sub.i,y'.sub.i } to the next signer (i+1). A verifier calculates e.sub.i and d.sub.i with the one-way functions f.sub.i and h.sub.i using X'.sub.L and m'.sub.L contained in received information {ID'.sub.L, X'.sub.L, m'.sub.L, y.sub.L }, and makes a check to see if g.sup.y.sup..sub.L .tbd.X.sub.1.sup.d.sup..sub.1 I.sub.L.sup.e.sup..sub.1 . . . X.sub.L.sup.d.sup..sub.L I.sub.L.sup.e.sup..sub.L (mod p), thereby verifying signatures of the signers en bloc.