LINEAR PROVABLE SECURITY FOR A CLASS OF UNBALANCED FEISTEL NETWORK

A structure iterated by the unbalanced Feistel networks is introduced. It is showed that this structure is provable resistant against linear attack. The main result of this paper is that the upper bound of r-round （r≥2m） linear hull probabilities are bounded by q^2 when around function F is bijective and the maximal linear hull probabilities of round function F is q. Application of this structure to block cipher designs brings out the provable security against linear attack with the upper bounds of probabilities.

Provable Security of ID-Based Proxy Multi-Signature Schemes

In the last couple of years, D-based cryptography has got fruitful achievements. Proxy multi-signature allows a designated person, called a proxy signer, to sign on behalf of two or more original signers. In this paper, we present a general security model for ID-based proxy multi-signature （ID-PMS） schemes. Then, we show how to construct a secure ID-PMS scheme from a secure ID-based signature scheme, and prove that the security of the construction can be reduced to the security of the original ID-based signature scheme.

An Efficient and Provably Secure SM2 Key-Insulated Signature Scheme for Industrial Internet of Things

With the continuous expansion of the Industrial Internet of Things(IIoT),more andmore organisations are placing large amounts of data in the cloud to reduce overheads.However,the channel between cloud servers and smart equipment is not trustworthy,so the issue of data authenticity needs to be addressed.The SM2 digital signature algorithm can provide an authentication mechanism for data to solve such problems.Unfortunately,it still suffers from the problem of key exposure.In order to address this concern,this study first introduces a key-insulated scheme,SM2-KI-SIGN,based on the SM2 algorithm.This scheme boasts strong key insulation and secure keyupdates.Our scheme uses the elliptic curve algorithm,which is not only more efficient but also more suitable for IIoT-cloud environments.Finally,the security proof of SM2-KI-SIGN is given under the Elliptic Curve Discrete Logarithm(ECDL)assumption in the random oracle.

A novel pairing-free certificateless authenticated key agreement protocol with provable security

Recently, He et al. （Computers and Mathematics with Applications, 2012） proposed an efficient pairing-free certificateless authenticated key agreement （CL-AKA） protocol and claimed their protocol was provably secure in the extended Canetti-Krawczyk （eCK） model. By giving concrete attacks, we indicate that their protocol is not secure in the eCK model. We propose an improved protocol and show our improvement is secure in the eCK model under the gap DiffieHellman （GDH） assumption. Furthermore, the proposed protocol is very efficient.

Research on a provable security RFID authentication protocol based on Hash function

Research on existing radio frequency identification（RFID） authentication protocols security risks, poor performance and other problems, a RFID security authentication protocol based on dynamic identification（ID） and Key value renewal is proposed. Meanwhile, the security problems based on Hash function RFID security authentication protocol in recent years have been also sorted and analyzed. Then a security model to design and analyze RFID protocols is built. By using the computational complexity, its correctness and security have been proved. Compared with the safety performance, storage overhead, computational overhead and other aspects of other protocols, the protocol for RFID has more efficient performance and ability to withstand various attacks. And the C# programming language is used to simulate the authentication process on the visual studio platform, which verifies the feasibility of the protocol.

An Efficient Provable Secure ID-Based Proxy Signature Scheme Based on CDH Assumption

Identity-based proxy signature enables an entity to delegate its signing rights to another entity in identity-based cryptosystem settings. However, few existing scheme has been proved secure in a formalized model, or acquired optimized performance. To achieve the goals of both proven security and high efficiency, this paper proposed an efficient identity-based proxy signature scheme. The scheme is constructed from bilinear pairing and proved secure in the random oracle model, using the oracle replay attack technique introduced by Pointchval and Stern. The analysis shows that the scheme needs less computation costs and has a shorter signature than the other schemes.

Provable Efficient Certificateless Group Key Exchange Protocol

Certificateless public key cryptography （CL-PKC） avoids the inherent escrow of identity-based cryptography and does not require certificates to guarantee the authenticity of public keys. Based on CL-PKC, we present an efficient constant-round group key exchange protocol, which is provably secure under the intractability of computation Diffie-Hellman problem. Our protocol is a contributory key exchange with perfect forward secrecy and has only two communication rounds. So it is more efficient than other protocols. Moreover, our protocol provides a method to design efficient constant-round group key exchange protocols and most secret sharing schemes could be adopted to construct our protocol.

Efficient and Provably Secure Multi-Recipient Signcryption from Bilinear Pairings

Signcryption is a cryptographic primitive that performs signature and encryption simultaneously, at lower computational costs and communication overheads than the signature-then- encryption approach. In this paper, we propose an efficient multi-recipient signcryption scheme based on the bilinear pairings, which broadcasts a message to multiple users in a secure and authenticated manner. We prove its semantic security and unforgeability under the Gap Diffie-Hellman problem assumption in the random oracle model. The proposed scheme is more efficient than re-signcrypting a message n times using a signcryption scheme in terms of computational costs and communication overheads.

A Formal Model for the Security of Proxy Signature Schemes

This paper provides theoretical foundations for the secure proxy signatureprimitive. We pres-enta formal model for the security of proxy signature schemes, which defines thecapabilities of the adversary and the security goals to capture which mean for a prox-ysignaturescheme to be secure. Then, we present an example of proxy signature scheme that can be proven securein the standard model.

A Flaw in the Security Proof of BDOP-PEKS and PEKS-STAT

Provable security has been widely used for analyzing the security of cryptosystems. Its main idea is to reduce the security to some well-defined computational assumption. The reduction process is called the security proof. In this paper, we find a flaw in the security proof of BDOP-PEKS and PEKS-STAT, present a new conclusion for the security of BDOP-PEKS, and give a security proof. The flaw in the security proof of PEKS-STAT can be fixed in the same way. Finally we conclude some steps of security proof, and emphasize that the probability is as important as the construction.

Provably Secure Short Proxy Signature Scheme from Bilinear Maps

An enhanced formal model of security for proxy signature schemes is presented and a provably secure short proxy signature scheme is proposed from bilinear maps. The proposed proxy signature scheme is based on two short secure signature schemes. One is used for delegating the signing rights and computing the standard signature; the other is used for computing proxy signature. Finally, a security proof of the proposed proxy signature scheme is showed by reducing tightly the security of the proposed proxy signature scheme to the security of the two basic signature schemes. The proposed proxy signature scheme has the shortest ordinary signatures and proxy signatures. Moreover, the proxy signature generation needs no pairing operation and verification needs just two pairing operation.

A Provably Secure and Efficient Remote Password Authentication Scheme Using Smart Cards

Communication technology has advanced dramatically amid the 21st century,increasing the security risk in safeguarding sensitive information.The remote password authentication(RPA)scheme is the simplest cryptosystem that serves as the first line of defence against unauthorised entity attacks.Although the literature contains numerous RPA schemes,to the best of the authors’knowledge,only few schemes based on the integer factorisation problem(IFP)and the discrete logarithm problem(DLP)that provided a provision for session key agreement to ensure proper mutual authentication.Furthermore,none of the previous schemes provided formal security proof using the random oracle model.Therefore,this study proposed an improved RPA scheme with session key establishment between user and server.The design of the proposed RPA scheme is based on the widely established Dolev-Yao adversary model.Moreover,as the main contribution,a novel formal security analysis based on formal definitions of IFP and DLP under the random oracle model was presented.The proposed scheme’s performance was compared to that of other similar competitive schemes in terms of the transmission/computational cost and time complexity.The findings revealed that the proposed scheme required higher memory storage costs in smart cards.Nonetheless,the proposed scheme is more efficient regarding the transmission cost of login and response messages and the total time complexity compared to other scheme of similar security attributes.Overall,the proposed scheme outperformed the other RPA schemes based on IFP and DLP.Finally,the potential application of converting the RPA scheme to a user identification(UI)scheme is considered for future work.Since RPA and UI schemes are similar,the proposed approach can be expanded to develop a provably secure and efficientUI scheme based on IFP and DLP.

Provably Secure Identity-based Group Key Exchange Protocol

Group key management is one of the basic building blocks in securing group communication.A number of solutions to group key exchange have been proposed,but most of them are not scalable and,in particular,require at least 0(log n) communication rounds.We formally present a constant -round Identity-based protocol with forward secrecy for group key exchange,which is provably secure in the security model introduced by Bresson et al.Our protocol focuses on round efficiency and the number of communication round is only one greater than the lower bound presented by Becker and Wille.And,the protocol provides a batch verification technique,which simultaneously verifies the validity of messages from other group participants and greatly improves computational efficiency.Moreover,in our protocol,it is no necessary of always-online key generation center during the execution of the protocol compared to other Identity-based protocols.

A PROVABLY SECURE PROXY SIGNATURE SCHEME FROM BILINEAR PAIRINGS

A proxy signature allows an entity, called original signer, to delegate its signing power to another entity, called proxy signer, to sign messages on its behalf. Proxy signatures have many practical applications and are very important cryptographic protocol. In this paper, we propose an efficient proxy signature scheme from bilinear pairings. We prove it secure in the random oracle model and analyze computation cost of our scheme. Our scheme satisfies all the properties required for proxy signatures.

A Novel Provable Data Possession Scheme Based on Geographic Location Attribute

Increment of mobile cloud video motivates mobile users to utilize cloud storage service to address their demands,cloud storage provider always furnish a location-independent platform for managing user's data.However,mobile users wonder if their cloud video data leakage or dynamic migration to illegal service providers.In this paper,we design a novel provable data possession protocol based on data geographic location attribute,which allows data owner to auditing the integrity of their video data,which put forward an ideal choice for remote data possession checking in the mobile cloud storage.In our proposed scheme,we check out whether the video data dynamic migrate to an unspecified location(such as:overseas) by adding data geographic location attribute tag into provable data possession protocol.Moreover,we make sure the security of our proposed scheme under the Computational Diffie-Hellman assumption.The analysis and experiment results demonstrate that our proposed scheme is provably secure and efficient.

Proofs of Security for Improved Rabin Signature Scheme

The improved RSA signature scheme can be strictly proved to be equivalent to the factoring problem. In the improved RSA signature scheme, when the public exponent e=1, the scheme becomes the improved Rabin signature. Such an improved Rabin signature scheme is reviewed and the techniques from the provable security is applied to analyze its security.

A Provably Secure Asynchronous Proactive RSA Scheme

The drawback of the first asynchronous proactive RSA scheme presented by Zhou in 2001, is that the security definition and security proof do not follow the approach of provable security. This paper presented a provably secure asynchronous proactive RSA scheme, which includes three protocols: initial key distribution protocol, signature generation protocol and share refreshing protocol. Taken these protocols together, a complete provably secure proactive RSA scheme was obtained. And the efficiency of the scheme is approximate to that of the scheme of Zhou.

安全协议形式化分析方法研究综述

介绍了安全协议的基本概念和分类,然后对安全协议形式化分析方法进行了详细介绍,包括基于模态逻辑的方法、基于模型检测的方法、基于定理证明的方法和基于可证明安全性理论的方法。其中,基于模型检测的方法是目前应用最广泛的一种方法,因此详细介绍了一些常用的基于模型检测方法的工具。最后,总结了当前安全协议形式化分析方法的研究热点和未来的发展方向。

格上无非交互式零知识证明的两轮三方PAKE协议

针对现有基于格的三方口令认证密钥交换(PAKE)协议通信轮次较多、执行效率较低等问题,提出一种格上无非交互式零知识证明的两轮三方PAKE协议。首先,利用非适应性近似平滑投影哈希函数实现密钥交换,在不使用非交互式零知识(NIZK)证明的前提下,降低协议的通信轮数;其次,利用哈希值和投影哈希值构造会话密钥,不需要使用随机预言机,避免了随机预言机导致的潜在口令猜测攻击。在标准模型下给出所提协议的形式化安全证明。仿真结果表明,与基于格的三方PAKE协议相比,所提协议的执行时间在客户端缩短了89.2%~98.6%,在服务器端缩短了19.0%~91.6%。验证了所提协议能够抵抗量子攻击,具有较高的执行效率,同时减少了协议通信轮数。