Public Key Cryptography Based on Ergodic Matrices over Finite Field

A new public key encryption scheme is proposed in this paper, which is based on a hard problem over ergodic matrices. The security of this scheme is equal to the MQ-problem： multivariate quadratic equations over finite fields. This problem has been shown to be NP-complete and can＇t be solved with polynomial time algorithm.

A New Fast Modular Arithmetic Method in Public Key Cryptography

Modular arithmetic is a fundamental operation and plays an important role in public key cryptosystem. A new method and its theory evidence on the basis of modular arithmetic with large integer modulus-changeable modulus algorithm is proposed to improve the speed of the modular arithmetic in the presented paper. For changeable modulus algorithm, when modular computation of modulo n is difficult, it can be realized by computation of modulo n-1 and n-2 on the perquisite of easy modular computations of modulo n-1 and modulo n-2. The conclusion is that the new method is better than the direct method by computing the modular arithmetic operation with large modulus. Especially, when computations of modulo n-1 and modulo n-2 are easy and computation of modulo n is difficult, this new method will be faster and has more advantages than other algorithms on modular arithmetic. Lastly, it is suggested that the proposed method be applied in public key cryptography based on modular multiplication and modular exponentiation with large integer modulus effectively

How to Integrate Abstract Algebra and Number Theory in the Teaching of Public Key Cryptography Elegantly

Different from traditional symmetric cryptography, public key cryptography allows each user to own a pair of public/private key pair. Given the public key of one user and the data to be encrypted, a ciphertext can be generated such that only the intended user is able to recover the data using his/her private key associated with public key involved in the encryption process. To really understand the philosophy behind the public key cryptography is not an easy task and sometimes it seems somewhat difficult, if not impossible, for the beginners without the knowledge of the abstract algebra and number theory. In this paper, we introduce briefly the basic definition of public key cryptography as well as the corresponding mathematical hard problems. Besides, we explain why the mathematical backgrounds, especially abstract algebra and number theory, matter in the study of public key cryptography.

A New Proxy Signature Scheme with Message Recovery Using Self-Certified Public Key

A proxy signature scheme with message recovery using self-certified public key is proposed, which withstands public key substitution attacks, active attacks, and forgery attacks. The proposed scheme accomplishes the tasks of public key verification, proxy signature verification, and message recovery in a logically single step. In addition, the proposed scheme satisfies all properties of strong proxy signature and does not use secure channel in the communication between the original signer and the proxy signature signer.

Multivariate Public-Key Encryption Scheme Based on Error Correcting Codes

Advances in quantum computers pose potential threats to the currently used public-key cryptographic algorithms such as RSA and ECC.As a promising candidate against attackers equipped with quantum computational power,Multivariate Public-Key Cryptosystems(MPKCs)has attracted increasing attention in recently years.Unfortunately,the existing MPKCs can only be used as multivariate signature schemes,and the way to construct an efficient MPKC enabling secure encryption remains unknown.By employing the basic MQ-trapdoors,this paper proposes a novel multivariate encryption scheme by combining MPKCs and code-based public-key encryption schemes.Our new construction gives a positive response to the challenges in multivariate public key cryptography.Thorough analysis shows that our scheme is secure and efficient,and its private key size is about 10 times smaller than that of McEliece-type cryptosystems.

A Multivariate Public Key Cryptographic Scheme

This paper presents a multivariate public key cryptographic scheme over a finite field with odd prime characteristic.The idea of embedding and layering is manifested in its construction.The security of the scheme is analyzed in detail,and this paper indicates that the scheme can withstand the up to date differential cryptanalysis.We give heuristic arguments to show that this scheme resists all known attacks.

A novel mutual authentication and key agreement protocol based on NTRU cryptography for wireless communications

In this paper, the authors present a novel mutual authentication and key agreement protocol based on the Number Theory Research Unit (NTRU) public key cryptography. The symmetric encryption, hash and “challenge-response” techniques were adopted to build their protocol. To implement the mutual authentication and session key agreement, the proposed protocol contains two stages: namely initial procedure and real execution stage. Since the lightweight NTRU public key cryptography is employed, their protocol can not only overcome the security flaws of secret-key based authentication protocols such as those used in Global System for Mobile Communications (GSM) and Universal Mobile Telecommunications System (UMTS), but also provide greater security and lower computational complexity in comparison with currently well-known public key based wireless authentication schemes such as Beller-Yacobi and M.Aydos protocols.

A New Self-Generated-Certificate Public Key Encryption Scheme with Flexible Public Key

Self-Generated-Certificate Public Key Cryptography(SGC-PKC) ,is the enhanced version of Certificateless Public Key Cryptography(CL-PKC) . It preserves all advantages of CL-PKC. Similar to CL-PKC,every user is given a partial private key by the KGC and generates his own private key and corresponding public key. In addition,it can defend against the Denial-of-Decryption(DoD) Attack. In this paper,we propose a new approach to construction SGC-PKE scheme that derived from a new application of chameleon hash and give a concrete scheme. It is the first scheme which has flexible public key and reaches Girault's trusted level 3,the same level as is enjoyed in a traditional PKI.

Applying Evolutionary Algorithm to Public Key Cryptosystems

A best algorithm generated scheme is proposed in the paper by making use of the thought of evolutionary algorithm, which can generate dynamically the best algorithm of generating primes in RSA cryptography under different conditions. Taking into account the factors of time, space and security integrated, this scheme possessed strong practicability. The paper also proposed a model of multi-degree parallel evolutionary algorithm to evaluate synthetically the efficiency and security of the public key cryptography. The model contributes to designing public key cryptography system too.

基于PKCS的数据安全框架及支持库设计

提出了一个基于 PKCS( Public Key Cryptography Standards)的数据安全框架 .该框架的最底层是输入、输出与编码模块 ,它主要实现了 BER( Basic Encoding Rule) /DER( Distinguish En-coding Rule)、Base64等编码与解码 ,以及与多种存储点之间的输入与输出 .此模块中使用流模块结构实现一次性处理 .PKCS所涉及的算法基础类库是整个框架的核心 ,其上是 X.50 9证书服务模块与 PKCS#7、PKCS#1 2数据保护模块 .框架中的个人安全环境管理模块主要用于维护用户口令、私钥和证书等信息 .文中提出的

基于USB Key的J2EE双因素认证系统

分析单一认证的弱安全性,结合智能卡PKCS11标准和J2EE组件技术,设计并实现基于用户口令(PIN)认证和硬件USBKey数字证书身份认证的双重因素认证系统。在此设计模型基础上,重点描述双因素认证系统的安全认证协议、J2EE应用中实现过程、关键签名、认证算法。应用结果显示,在性能相近的基础上,安全性较高。

Efficient Certificateless Authenticated Key Agreement Protocol from Pairings

In the area of secure Web information system, mutual authentication and key agreement are essential between Web clients and servers. An efficient certificateless authenticated key agreement protocol for Web client/server setting is proposed, which uses pairings on certain elliptic curves. We show that the newly proposed key agreement protocol is practical and of great efficiency, meanwhile, it satisfies every desired security require ments for key agreement protocols.

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.

NTRU_SSS:Anew Method Signcryption Post Quantum Cryptography Based on Shamir’s Secret Sharing

With the advent of quantum computing,numerous efforts have been made to standardize post-quantum cryptosystems with the intention of(eventually)replacing Elliptic Curve Cryptography(ECC)and Rivets-Shamir-Adelman(RSA).A modified version of the traditional N-Th Degree Truncated Polynomial Ring(NTRU)cryptosystem called NTRU Prime has been developed to reduce the attack surface.In this paper,the Signcryption scheme was proposed,and it is most efficient than others since it reduces the complexity and runs the time of the code execution,and at the same time,provides a better security degree since it ensures the integrity of the sent message,confidentiality of the data,forward secrecy when using refreshed parameters for each session.Unforgeability to prevent the man-in-the-middle attack from being active or passive,and non-repudiation when the sender can’t deny the recently sent message.This study aims to create a novel NTRU cryptography algorithm system that takes advantage of the security features of curve fitting operations and the valuable characteristics of chaotic systems.The proposed algorithm combines the(NTRU Prime)and Shamir’s Secret Sharing(SSS)features to improve the security of the NTRU encryption and key generation stages that rely on robust polynomial generation.Based on experimental results and a comparison of the time required for crucial exchange between NTRU-SSS and the original NTRU,this study shows a rise in complexity with a decrease in execution time in the case when compared to the original NTRU.It’s encouraging to see signs that the suggested changes to the NTRU work to increase accuracy and efficiency.

On the Group Based Cryptography

There are quite more applications of group theory. The recent application of group theory is public key （asymmetric） cryptography. All cryptographic algorithms have some weaknesses. To avoid its weakness, some special groups and methods can applied on. We will touch on group based public key cryptography and will give some suggestions in this area.

Hash Function Based Keyword Searchable Encryption Framework in Cloud Server Using MD5 and MECC

Cloud Computing expands its usability to various fields that utilize data and store it in a common space that is required for computing and the purpose of analysis as like the IoT devices.These devices utilize the cloud for storing and retrieving data since the devices are not capable of storing processing data on its own.Cloud Computing provides various services to the users like the IaaS,PaaS and SaaS.The major drawback that is faced by cloud computing include the Utilization of Cloud services for the storage of data that could be accessed by all the users related to cloud.The use of Public Key Encryptions with keyword search(PEKS)provides security against the untrustworthy third-party search capability on publicly encryption keys without revealing the data’s contents.But the Security concerns of PEKs arise when Inside Keywords Guessing attacks(IKGA),is identified in the system due to the untrusted server presume the keyword in trapdoor.This issue could be solved by using various algorithms like the Certificateless Hashed Public Key Authenticated Encryption with Keyword Search(CL-HPAEKS)which utilizes the Modified Elliptic Curve Cryptography(MECC)along with the Mutation Centred flower pollinations algorithm(CM-FPA)that is used in enhancing the performance of the algorithm using the Optimization in keys.The additional use of Message Digests 5(MD5)hash function in the system enhances the security Level that is associated with the system.The system that is proposed achieves the security level performance of 96 percent and the effort consumed by the algorithm is less compared to the other encryption techniques.

新的无证书代理盲签名方案

无证书公钥密码学既不存在传统的公钥密码系统的证书管理耗费,也不存在基于身份的密码系统中的密钥托管问题,安全且高效。研究了代理盲签名方案的构造和应用,发现现有的无证书代理盲签名方案较少,而在无证书密码系统中研究代理盲签名会更容易满足其在电子投票、电子银行等应用领域中对安全性和高效性的要求。基于双线性对知识和离散对数困难问题,提出了一种无证书代理盲签名方案,该方案满足盲性、不可伪造性、可鉴别性、不可否认性等性质。

一种可撤销匿名性的环签名方案

环签名提供了匿名发布信息的有效方法,现有环签名方案存在不可追踪签名者真实身份的问题。基于身份密码体制和双线性对技术,提出了一种环签名方案,方案除了满足无条件匿名性和不可伪造性,还满足可撤销匿名性,必要时由PKG(Private Key Generator)充当仲裁验证者,达到定位真实签名者的目的。

标准模型下可证安全的有效无证书签密方案

目前大多数无证书签密方案都是在随机预言模型下提出的,针对随机预言模型下的方案往往无法在实际应用中构造相应实例这一问题,采用标准模型的方法来进行构造。在对几个已有标准模型下相应方案分析的基础上,指出它们都是不安全的。以Au等所提出的方案(AU M H,LIU J K,YUEN T H,et al.Practical hierarchical identity based encryption and signature schemes without random oracles.http://eprint.iacr.org/2006/368.pdf)为基础,利用椭圆曲线上的双线性对性质,提出了一个新的标准模型下可证安全的无证书签密方案。最后,利用决策双线性Diffie-Hellman(DBDH)等困难问题,证明该方案满足适应性选择密文攻击下的不可区分性以及适应性选择消息和身份攻击下的存在不可伪造性,因而方案是安全可靠的。

基于无证书密钥协商的Kerberos改进协议

Kerberos认证协议容易遭受口令攻击和重放攻击,且需要2次双线性对运算、2次指数运算和1次椭圆曲线上的点乘运算,计算量大。为此,利用高效的无证书密钥协商对Kerberos协议进行改进。用户与认证服务器之间通过使用无证书签密技术抵抗伪造攻击。分析结果证明,改进协议符合密钥协商的6个基本安全要求,满足已知密钥安全性、完美前向安全性、抗未知密钥共享安全性、密钥不可控性、已知会话临时信息安全性,能抵抗口令攻击、重放攻击、中间人攻击及密钥泄漏伪装攻击,并且仅需3次点乘运算,具有较高的效率。