IDENTITY-BASED MULTISIGNATURE AND AGGREGATE SIGNATURE SCHEMES FROM M-TORSION GROUPS

An identity-based multisignature scheme and an identity-based aggregate signature scheme are proposed in this paper. They are both from m-torsion groups on super-singular elliptic curves or hyper-elliptic curves and based on the recently proposed identity-based signature scheme of Cha and Cheon. Due to the sound properties of m-torsion groups and the base scheme, it turns out that our schemes are very simple and efficient. Both schemes are proven to be secure against adaptive chosen message attack in the random oracle model under the normal security notions with the assumption that the Computational Diffie-Hellman problem is hard in the m-torsion groups.

IDENTITY-BASED KEY-INSULATED PROXY SIGNATURE

In proxy signature schemes,the proxy signer B is permitted to produce a signature on behalf of the original signer A. However,exposure of proxy signing keys can be the most devastating attack on a proxy signature scheme since any adversary can sign messages on behalf of the proxy signer. In this paper,we applied Dodis,et al.’s key-insulation mechanism and proposed an Identity-Based (ID-based) Key-Insulated Proxy Signature (IBKIPS) scheme with secure key-updates. The proposed scheme is strong key-insulated and perfectly key-insulated. Our scheme also supports unbounded period numbers and random-access key-updates.

An Identity-Based Strong Designated Verifier Proxy Signature Scheme

In a strong designated verifier proxy signature scheme, a proxy signer can generate proxy signature on behalf of an original signer, but only the designated verifier can verify the validity of the proxy signature. In this paper, we first define the security requirements for strong designated verifier proxy signature schemes. And then we construct an identity-based strong designated verifier proxy signature scheme. We argue that the proposed scheme satisfies all of the security requirements.

Identity-based ring signature scheme based on quadratic residues

Identity-based （ID-based） ring signature has drawn great concerns in recent years and many ID-based ring signature schemes have been proposed until now. Unfortunately, all of these ID-based ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based ring signature without pairing is of great interest in the field of cryptography. In this paper, the authors firstly propose an ID-based ring signature scheme based on quadratic residues. The proposed scheme is proved to be existentially unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring. The proposed scheme is more efficient than those which are constructed from bilinear pairings.

Trusted Routing Based on Identity-Based Threshold Signature for Opportunistic Networks

In opportunistic Networks,compromised nodes can attack social context-based routing protocols by publishing false social attributes information.To solve this problem,we propose a security scheme based on the identity-based threshold signature which allows mobile nodes to jointly generate and distribute the secrets for social attributes in a totally self-organized way without the need of any centralized authority.New joining nodes can reconstruct their own social attribute signatures by getting enough partial signature services from encounter opportunities with the initial nodes.Mobile nodes need to testify whether the neighbors can provide valid attribute signatures for their routing advertisements in order to resist potential routing attacks.Simulation results show that:by implementing our security scheme,the network delivery probability of the social context-based routing protocol can be effectively improved when there are large numbers of compromised nodes in opportunistic networks.

Non-interactive identity-based threshold signature scheme without random oracles

A (t, n) threshold signature scheme distributes the secret key and hence the signing ability to n players in a way that any set of t+1 or more honest players can collaborate to sign, while any set of t players cannot. In this paper we propose an iden- tity-based threshold signature (IBTHS) scheme from bilinear pairings. The signing phase of our scheme is non-interactive, meaning that the signing players do not need to talk to each other. We prove our scheme secure (i.e., unforgeable and robust) in the standard model (i.e., without random oracles). No earlier proposed IBTHS scheme achieved even one of the features of being non-interactive (in the signing phase) and secure in the standard model.

An Improved Identity-Based Society Oriented Signature Scheme with Anonymous Signers

In this paper, we present an improved identity-based society oriented signature scheme with anonymous signers, which satisfies： （1） when members leave or join an organization, the public verification key and the signature verification procedure are unchanged; （2） a user participates in several organizations at the same time, her secret key is only related with her identity. However, no previous schemes have these two properties.

An Identity-Based Scheme of Fair Exchange of Digital Signatures

Fair exchange of digital signatures is an important tool for signing digital contracts, e-payment and other electronic commerce actions. An ID-based scheme of fair exchange of digital signature is proposed in this paper. The protocol relies on a trusted third party, but is ＂optimistic＂, in that the third party is only needed in cases where one player attempts to cheat or simply crashes. The proposed scheme has properties of short signature, low computation and verification cost. It can realize exchange of digital signatures fairly and effic, iently. A key feature of our scheme is that it is identity-based, which needs no certificates and has a simple key management. To our best knowledge, this is the first identity based scheme of fair exchange of digital signatures.

Feasibility analysis of two identity-based proxy ring signature schemes

Recently, proxy ring signature schemes have been shown to be useful in various applications, such as electronic polling, electronic payment, etc. Although many proxy ring signature schemes have been pro-posed, there are only two identity-based proxy ring signature schemes have been proposed until now, i. e., Cheng＇s scheme and Lang＇s scheme. It＇s unlucky that the two identity-based proxy ring signature schemes are unfeasible. This paper points out the reasons why the two identity-based proxy ring signature schemes are unfeasible. In order to design feasible and efficient identity-based proxy ring signature schemes from bilinear pairings, we have to search for other methods.

Improvement of Identity-Based Threshold Proxy Signature Scheme with Known Signers

In 2006, Bao et al proposed an identlty-based threshold proxy signature scheme with known signers. In this paper, we show that Bao et al＇s scheme is vulnerable to the forgery attack. An adversary can forge a valid threshold proxy signature for any message with knowing a previously valid threshold proxy signature. In addition, their scheme also suffers from the weakness that the proxy signers might change the threshold value. That is, the proxy signers can arbitrarily modify the threshold strategy without being detected by the original signer or verifiers, which might violate the original signer＇s intent. Furthermore, we propose an improved scheme that remedies the weaknesses of Bao et al＇s scheme. The improved scheme satisfies all secure requirements for threshold proxy signature.

Identity-based Verifiably Committed Signature Scheme without Random Oracles

An identity-based verifiably committed signature scheme (IB-VCS) was proposed, which is proved secure in the standard model (i.e., without random oracles). It enjoys the setup-free property and stand-alone property, both of which make an exchange protocol more practical. The scheme is unconditionally secure against the cheating signer, its security against the cheating verifier is reduced to the computational Diffie-Hellman (CDH) problem in the underlying group, it is secure against the cheating trusted third party if the underlying Paterson Schuldt's identity based signature (IBS) scheme is secure, which is proven true based on the CDH assumption in the standard model.

Short(t,n) Threshold Signature

This paper presents a short(t,n) threshold signature scheme.Its security is based on a variant of the discrete logarithm problem(DLP),which is proved to be robust and unforgeable.

NEW ID-BASED GROUP SIGNATURE FROM PAIRINGS

We argue that traditional identity-based systems from pairings seem unsuitable for designing group signature schemes due to the problem of key escrow. In this paper we first propose new ID-based public key systems without trusted PKG (Private Key Generator) from bilinear pairings. In our new ID-based systems, if the dishonest PKG impersonates an honest user to communicate with others, the user can provide a proof of treachery of the PKG afterwards, which is similar to certificate-based systems. Therefore, our systems reach the Girault’s trusted level 3. We then propose a group signature scheme under the new ID-based systems, the security and performance of which rely on the new systems. The size of the group public key and the length of the signature are independent on the numbers of the group.

Verifiably Encrypted Signatures Without Random Oracles

Verifiably encrypted signatures are employed when a signer wants to sign a message for a verifier but does not want the verifier to possess his signature on the message until some certain requirements of his are satisfied. This paper presented new verifiably encrypted signatures from bilinear pairings. The proposed signatures share the properties of simplicity and efficiency with existing verifiably encrypted signature schemes. To support the proposed scheme, it also exhibited security proofs that do not use random oracle assumption. For existential unforgeability, there exist tight security reductions from the proposed verifiably encrypted signature scheme to a strong but reasonable computational assumption.

Efficient ID-Based Proxy Blind Signature Scheme

In a proxy blind signature scheme, the proxy signer is allowed to generate a blind signature on behalf of the original signer. The proxy blind signature scheme is useful in several applications such as e-voting and e-payment. In this paper, we propose an identity-based proxy blind signature scheme which combines the advantages of proxy signature and of blind signature. Our scheme fulfills peffecdy the security requirements of a proxy blind signature. Comparing the previous scheme, our scheme needs less computational overhead and is more efficient.

A new improved ID-based proxy ring signature scheme from bilinear pairings

Ring signature and proxy signature are of vital importance to secure electronic commerce. Recently, the bilinear pairing such as Well pairing or Tate pairing on elliptic curves and hyperelliptic curves is playing an important role in security solutions. Several ID-based signature schemes have been put forward, many of which are based on bilinear pairings. In key management and moderate security demand scenarios, ID-based public key cryptosystem is more preferable than other public key infrastructure based systems. In this paper, an improved ID-based proxy ring signature scheme from bilinear pairings is proposed which combines the advantages of proxy signature and of ring signatures. Our scheme can guarantee the profits of the proxy signer via preventing the original signer form generating the proxy ring signature. Furthermore, bilinear pairings are introduced to minimize the computation overhead and to improve the related performance of our scheme. In contrast with Zhang＇s scheme, our scheme is a computational efficiency improvement for signature verification because the computational cost of bilinear pairings required is reduced from O（n） to O（ 1 ）. In addition, the proxy ring signature presented in this paper can perfectly satisfy all the security requirements of proxy ring signature, i. e. signer-ambiguity, non-forgeability, verification, non-deniability and distinguishability.

A NEW MULTI-PROXY SIGNATURE FROM BILINEAR PAIRING

Proxy signatures are very useful tools when one needs to delegate his/her signing capability to other parties. In this paper,a new multi-proxy signature scheme is proposed. The new scheme is constructed from bilinear pairings using Boneh,Lynn,and Shacham’s (BLS) short signatures. The proxy key for the proxy group is just a short signature on the proxy warrant generated by the original signer. Due to the use of short signatures,our scheme is not only efficient,but also satisfies all the security requirements of the strong proxy signature.

Pairing-Free ID-Based Key-Insulated Signature Scheme

Without the assumption that the private keys are kept secure perfectly, cryptographic primitives cannot be deployed in the insecure environments where the key leakage is inevitable. In order to reduce the damage caused by the key exposure in the identity-based（ID-based） signature scenarios efficiently, we propose an ID-based key-insulated signature scheme in this paper, which eliminates the expensive bilinear pairing operations. Compared with the previous work, our scheme minimizes the computation cost without any extra cost. Under the discrete logarithm（DL） assumption, a security proof of our scheme in the random oracle model has also been given.

ForenSeq^(TM) DNA Signature Prep试剂盒在浙江畲族人群中的法医学应用

目的评估ForenSeq^(TM) DNA Signature Prep试剂盒(以下简称ForenSeq试剂盒)对浙江畲族人群STR序列的解读能力及法医学应用效能。方法应用MiSeq FGx法医基因组学系统和ForenSeq试剂盒对50例浙江畲族人群样本进行大规模平行测序(massively parallel sequencing,MPS)检测,采用ForenSeq^(TM)通用分析软件分析测序数据,获取58个STR基因座的分型结果及序列结构信息。将MPS与PCR-CE技术的分型结果进行一致性比对,并计算等位基因频率和群体遗传学参数。结果在50例浙江畲族人群样本中,共观察到448种序列多态性等位基因,与PCR-CE技术检测的片段长度多态性结果相比,基于ForenSeq试剂盒的MPS检测增加了82个等位基因,在6个基因座的侧翼区共发现7个SNP变异。22例男性的24个Y染色体STR基因座中共检测到19种单倍型。27个常染色体STR基因座的累积个体识别率为1-8.87×10^(-30),累积二联体非父排除率为0.999999962640657,累积三联体非父排除率为0.999999999999633。结论基于MiSeq FGx法医基因组学系统使用ForenSeq试剂盒进行MPS检测,极大提高了检测效能。58个STR基因座在所调查的浙江畲族人群中具有良好的遗传多态性,可应用于法医学个体识别和亲权鉴定。

An efficient identity-based signature protocol over lattices for the smart grid

As the promising next-generation power grid,the smart grid has developed rapidly in recent years.The smart grid enables energy to be stored and delivered more efficiently and safely,but user data’s integrity protection has been an important security issue in the smart grid.Although lots of digital signature protocols for the smart grid have been proposed to resolve this problem,they are vulnerable to quantum attacks.To deal with this problem,an efficient identity-based signature protocol on lattices is proposed in this paper.To improve our protocol’s efficiency,the tree of commitments is utilized.Moreover,a detailed performance evaluation of the proposed protocol is made.The performance analysis demonstrates that the potential utility of our protocol in the smart grid is huge.