DocumentCode :
3608096
Title :
Cryptanalysis and improvement of a certificateless partially blind signature
Author :
Lin Cheng ; Qiaoyan Wen
Author_Institution :
Tech. Assessment Res. Lab., China Inf. Technol. Security Evaluation Center, Beijing, China
Volume :
9
Issue :
6
fYear :
2015
Firstpage :
380
Lastpage :
386
Abstract :
Partially blind signature is an important technique in secure electronic cash (e-cash) system. The first concrete certificateless partially blind signature (CLPBS) scheme for e-cash was constructed in 2011. Recently it was found that this construction had a security weakness and a rescued scheme was given. Unfortunately, the formal security proof was not given. In this study, the authors first give cryptanalysis of their rescued scheme. They demonstrate that a malicious user in their rescued scheme can forge a signature on any message by replacing the signer´s public key. In an e-cash system, blind signatures issued by the bank are viewed as e-cash. Once they apply their scheme to an untraceable e-cash system, a malicious user can forge valid electronic coins (i.e. valid signatures) without being detected by the bank. It will result in loss of the bank. Then, they propose a newly improved CLPBS scheme which achieves the strongest security level and has higher computational efficiency than the rescued scheme published earlier. Finally, they give an example of potential application to e-cash systems using their scheme.
Keywords :
digital signatures; electronic money; public key cryptography; CLPBS scheme; certificateless partially blind signature scheme; cryptanalysis; e-cash system; electronic coins; formal security proof; rescued scheme; secure electronic cash system; security weakness; signer public key;
fLanguage :
English
Journal_Title :
Information Security, IET
Publisher :
iet
ISSN :
1751-8709
Type :
jour
DOI :
10.1049/iet-ifs.2014.0293
Filename :
7295685
Link To Document :
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