Font Size: a A A

Study On The New Construction And Security Of Digital Signatures In The Multi-user Setting

Posted on:2014-01-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:B N DouFull Text:PDF
GTID:1228330395983695Subject:Computer application technology
Abstract/Summary:PDF Full Text Request
Signature schemes are always related to the multi-user settings. Firstly, a signature is generated by many users, such signature schemes are called multi-party signature schemes; secondly, we will consider the security of a signature scheme in the multi-user setting, although the signature is generated by only one user.Multisignature schemes (MS scheme), aggregate signature schemes (AS scheme) and verifiably encrypted signature schemes (VES scheme) are related to each other, and all of them are multi-party signature schemes. MS schemes, AS schemes and VES schemes are very useful in the fields of Contract Signing, Digital Certificate Issue, and Fair Exchange Protocol etc. This dissertation studies the new constructions of MS schemes, AS schemes, and VES schemes; and also studies the security of these three schemes and other signature schemes in the multi-user setting.The main contributions of the dissertation are as follows.(1). We proposed a secure Identity-based sequential aggregate signature scheme from RSA. Most of the existing MS schemes, AS schemes, and VES schemes are based on pair-ings. Pairings were only recently introduced to the cryptography community, and are not understood as much as RSA and DLP by cryptographers; additionally, the in-use designs of cryptography schemes are not pairing oriented but RSA or DLP oriented. Hence, it is valuable to construct these three schemes and their modifications from RSA or DLP.(2). We proposed a quantum-immune sequential aggregate signature. It is known that if large scale quantum computers can be realized, then all the cryptosystems which are based on Parings, RSA and DLP are not secure any more. Hence, all the the exist-ing MS schemes, AS schemes, and VES schemes which are based on pairings are not secure against quantum computers. Currently, it is very urgent for cryptographers to con-struct quantum-immune digital signatures. The dissertation proposed a quantum-immune sequential aggregate signature by using the problem of decoding of linear code.(3). We proposed a new type of signature schemes. Combining the VES schemes and MS schemes, we propose a new type of signature schemes with additional functionalities, which we call verifiably encrypted multi-signature schemes.(4). We analyzed the security of some VES schemes using rogue-key attacks. It is known that multi-party signature schemes should be secure against rogue-key attacks. The dissertation pointed out that the VES scheme proposed by Boneh et al. at Eurocrypt’03and the VES scheme proposed by Lu et al. at Eurocrypt’06are not secure against rogue-key attacks.(5). We pointed out that some signature schemes are not secure against key substitu-tion attacks.2004, Menezes et al. pointed out that, in the multi-user setting, the existing security model for signature schemes is not sufficient, and proposed a new type of attacks which they called the key substitution attacks (KS attack). The dissertation pointed out that the CFS signature proposed by Courtois et al. at Asiacrypt’01is not secure against KS attacks.(6). We pointed out that KS attacks can cause dangerous consequences when it comes to the security of MS schemes and VES schemes. It is known that multi-party signature schemes should be secure against rogue-key attacks; but is not known that, as to the se-curity of MS schemes and VES schemes, whether KS attacks is worth considering. The dissertation firstly pointed out that KS attacks can cause dangerous consequences when it comes to the security of MS schemes and VES schemes. As examples, we pointed out that the VES scheme proposed by Zhang et al. at Indocrypt’03and the MS scheme proposed by Boldyreva at PKC’03are not secure against KS attacks.
Keywords/Search Tags:Multisignature scheme, Aggregate signature scheme, Verifiably encryptedsignature scheme, RSA, CFS signature, Key sibstitution attack, Rogue-keyattack
PDF Full Text Request
Related items