Digital Signature Based on ISRSAC

Digital signature has recently played an increasingly important role in cyberspace security.Most of them are based on the public key cryptography.Public key cryptography is a mainstream cryptographic algorithm system that has been widely used in cyberspace security in recent years.The most classic public key cryptography algorithm is RSA and its difficulty is based on the large integer decomposition problem.In 2017,ISRSAC was proposed by M.Thangaval.ISRSAC has made security improvements to the RSA algorithm by increasing the complexity in factoring the value of modulus‘n’.A digital signature algorithm based on ISRSAC algorithm was completed in this paper,and furthermore,a proxy signature algorithm based on ISRSAC and two kinds of multi-signature algorithms were presented,which include sequential multi-signature and broadcasting multi-signature.

Digital Multi-Signature Based on the Controlled Quantum Teleportation

In this paper, a scheme which can be used in multi-user quantum digital signature is proposed. The scheme of signature and verification is based on the characters of GHZ （Greenberger-Horne-Zeilinger） states and controlled quantum teleportation. Different from the digital signatures based on computational complexity, this scheme is unconditional secure, and compared to the former presented quantum signature scheme, it does not rely on an arbitrator to verify the signature and realize a message can be signed by multi-user together.

Digital signature systems based on smart card and fingerprint feature

Two signature systems based on smart cards and fingerprint features are proposed. In one signature system, the cryptographic key is stored in the smart card and is only accessible when the signer＇s extracted fingerprint features match his stored template. To resist being tampered on public channel, the user＇s message and the signed message are encrypted by the signer＇s public key and the user＇s public key, respectively. In the other signature system, the keys are generated by combining the signer＇s fingerprint features, check bits, and a rememberable key, and there are no matching process and keys stored on the smart card. Additionally, there is generally more than one public key in this system, that is, there exist some pseudo public keys except a real one.

Merkle Tree Digital Signature and Trusted Computing Platform

Lack of efficiency in the initial key generation process is a serious shortcoming of Merkle tree signature scheme with a large number of possible signatures. Based on two kinds of Merkle trees, a new tree type signature scheme is constructed, and it is provably existentially unforgeable under adaptive chosen message attack. By decentralizing the initial key generation process of the original scheme within the signature process, a large Merkle tree with 6.87×10^10 possible signatures can be initialized in 590 milliseconds. Storing some small Merkle trees in hard disk and memory can speed up Merkle tree signature scheme. Mekle tree signature schemes are fit for trusted computing platform in most scenarios.

A DIGITAL SIGNATURE-BASED VISUAL CRYPTOGRAPHY SCHEME FOR IMAGE DISCRIMINATION AND MANAGEMENT

Visual cryptography is a cryptographic technique which emerges in the information security domain in recent years. Each of the sharing sub-keys may be a stochastic noise image or a significative image with no information on the original key. But a mass of sub-keys have to be saved actually, which faces the problem of inconvenient discrimination and management. This paper presents a visual cryptography scheme based on the digital signature for image discrimination and management, applying the digital signature and the time-stamp technology to the visual cryptography scheme. The scheme both solves the problem on the storage and management of the sharing sub-keys, increases the verification of image contents, thus enhances the validity of storage and management without security effect.

Conventional and Improved Digital Signature Scheme: A Comparative Study

Due to the rapid growth of online transactions on the Internet, authentication, non-repudiation and integrity are very essential security requirements for a secure transaction. To achieve these security goals, digital signature is the most efficient cryptographic primitive. Many authors have proposed this scheme and prove their security and evaluate the efficiency. In our paper, we present comprehensive study of conventional digital signature schemes based on RSA, DSA and ECDSA (Elliptic Curve Digital Signature Algorithm) and the improved version of these scheme.

Digital Signatures for e-Government - a Long-Term Security Architecture

The framework of digital signature based on qualified certificates and X. 509 architecture is known to have many security risks. Moreover, the fraud prevention mechanism is fragile and does not provide strong guarantees that can be necessary for flow of legal documents. Mediated signatures have been proposed as a mechanism to effectively disable signature cards. In this paper we propose further mechanisms that can be applied on top of mediated RSA, compatible with the standard format, but providing security guarantees even in the case when RSA becomes broken or the keys are compromised. The solution is immune tokleptographic attacks as only deterministic algorithms are used on user＇s side.

DESIGN OF A DIGITAL SIGNATURE SCHEME BASED ON FACTORING AND DISCRETE LOGARITHMS

Objective Focusing on the s ecurity problem of authentication and confidentiality in the context of computer networks, a digital signature scheme was proposed based on the public key crypt osystem. Methods Firstly, the course of digital signature based on the public key cryptosystem was given. Then, RSA and ELGamal schemes were de scribed respectively. They were the basis of the proposed scheme. Generalized EL Gamal type signature schemes were listed. After comparing with each other, one s cheme, whose Signature equation was (m+r)x=j+s modΦ(p) , was adopted in the des igning. Results Based on two well-known cryptographic assumpti ons, the factorization and the discrete logarithms, a digital signature scheme w as presented. It must be required that s' was not equal to p'q' in the signing p rocedure, because attackers could forge the signatures with high probabilities i f the discrete logarithms modulo a large prime were solvable. The variable publi c key “e” is used instead of the invariable parameter “3” in Harn's signatu re scheme to enhance the security. One generalized ELGamal type scheme made the proposed scheme escape one multiplicative inverse operation in the signing proce dure and one modular exponentiation in the verification procedure. Concl usion The presented scheme obtains the security that Harn's scheme was originally claimed. It is secure if the factorization and the discrete logarithm s are simultaneously unsolvable.

A New Digital Multilevel Proxy Signature Scheme Based on Elliptic Curve Cryptography

Based on the analysis of elliptic curve digital signature algorithm（ECDSA）,aiming at multilevel proxy signature in which the original signer delegates the digital signature authority to several proxies and its security demands, a new multilevel proxy signature scheme based on elliptic curve discrete logarithm problem （ECDLP） is presented and its security are proved.

A Secure Hardware Implementation for Elliptic Curve Digital Signature Algorithm

Since the end of the 1990s,cryptosystems implemented on smart cards have had to deal with two main categories of attacks:side-channel attacks and fault injection attacks.Countermeasures have been developed and validated against these two types of attacks,taking into account a well-defined attacker model.This work focuses on small vulnerabilities and countermeasures related to the Elliptic Curve Digital Signature Algorithm(ECDSA)algorithm.The work done in this paper focuses on protecting the ECDSA algorithm against fault-injection attacks.More precisely,we are interested in the countermeasures of scalar multiplication in the body of the elliptic curves to protect against attacks concerning only a few bits of secret may be sufficient to recover the private key.ECDSA can be implemented in different ways,in software or via dedicated hardware or a mix of both.Many different architectures are therefore possible to implement an ECDSA-based system.For this reason,this work focuses mainly on the hardware implementation of the digital signature ECDSA.In addition,the proposed ECDSA architecture with and without fault detection for the scalar multiplication have been implemented on Xilinxfield programmable gate arrays(FPGA)platform(Virtex-5).Our implementation results have been compared and discussed.Our area,frequency,area overhead and frequency degradation have been compared and it is shown that the proposed architecture of ECDSA with fault detection for the scalar multiplication allows a trade-off between the hardware overhead and the security of the ECDSA.

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.

Two Improved Digital Signature Schemes

In this paper, two improved digital signature schemes are presented based on the design of directed signature scheme. The peculiarity of the system is that only if the scheme is specific recipient, the signature is authenticated. Since the scheme adds the screen of some information parameters, the difficulty of deciphered keys and the security of digital signature system are increased.

A New Sequential Digital Multi-Signature Scheme

The paper proposes a new sequential digital multi-signature scheme based on Knapsack public-key cryptosystem,which is different from the existing scheme.The advantages of this scheme over the existing schemes are that it simplifies the signature generation process and speeds up the signature verification process.What’s more,the scheme reduces the cost of communication and redundancy operation, and improves efficiency,and can avoid cheating by signer efficiently,so the scheme has very broad application prospects.

Public-Key Cryptosystems with Secret Encryptor and Digital Signature

This paper describes and compares a variety of algorithms for secure transmission of information via open communication channels based on the discrete logarithm problem that do not require search for a generator (primitive element). Modifications that simplify the cryptosystem are proposed, and, as a result, accelerate its performance. It is shown that hiding information via exponentiation is more efficient than other seemingly simpler protocols. Some of these protocols also provide digital signature/sender identification. Numeric illustrations are provided.

Combining Public Key Encryption with Schnorr Digital Signature

This article presents a new signcryption scheme which is based on the Schnorr digital signature algorithm. The new scheme represents my personal contribution to signcryption area. I have implemented the algorithm in a program and here are provided the steps of the algorithm, the results and some examples. The paper also contains the presentation of the original Signcryption scheme, based on ElGamal digital signature and discusses the practical applications of Signcryption in real life. The purpose of the study is to combine the public key encryption with Schnorr digital signature in order to obtain less computational and communicational costs. Signcryption primitive is a better approach then Encrypt-then-Sign or Sign-then-Encrypt methods regarding the costs. All these algorithms offer the possibility to transmit a message over an insecure channel providing both authenticity and confidentiality.

Signature of Superconductivity in Pressurized La_(4)Ni_(3)O_(10)

The discovery of high-temperature superconductivity near 80K in bilayer nickelate La_(3)Ni_(2)O_(7)under high pressures has renewed the exploration of superconducting nickelate in bulk materials.The extension of superconductivity in other nickelates in a broader family is also essential.Here,we report the experimental observation of superconducting signature in trilayer nickelate La_(4)Ni_(3)O_(10)under high pressures.By using a modified solgel method and post-annealing treatment under high oxygen pressure,we successfully obtained polycrystalline La_(4)Ni_(3)O_(10)samples with different transport behaviors at ambient pressure.Then we performed high-pressure electrical resistance measurements on these samples in a diamond-anvil-cell apparatus.Surprisingly,the signature of possible superconducting transition with a maximum transition temperature(T_(c))of about 20K under high pressures is observed,as evidenced by a clear drop of resistance and the suppression of resistance drops under magnetic fields.Although the resistance drop is sample-dependent and relatively small,it appears in all of our measured samples.We argue that the observed superconducting signal is most likely to originate from the main phase of La_(4)Ni_(3)O_(10).Our findings will motivate the exploration of superconductivity in a broader family of nickelates and shed light on the understanding of the underlying mechanisms of high-T_(c) superconductivity in nickelates.

Forward-Secure Digital Signature Scheme with Tamper Evidence

Based on the definition of tamper evidence, the authors define a new notion of tamper evidence forward secure signature scheme （TE-FSig）, and propose a general method to build a TE-FSig scheme. Based on this method, they also give out a concrete instance. A TE-FSig scheme is constructed by the standard signature scheme, forward secures signature scheme and the aggregate signature scheme. It has an additional property of tamper evidence besides the property of forward secure, which can detect the time period when the key is exposed. In the standard model, the scheme constructed in the paper is proved to satisfy the prop- erties of forward secure, strong forward tamper-evidence secure, and strongly unforgeable under the chosen-message attack.

Digital signal acquisition system for complex nuclear reaction experiments

A digital data-acquisition system based on XIA LLC products was used in a complex nuclear reaction experiment using radioactive ion beams.A flexible trigger system based on a field-programmable gate array(FPGA)parametrization was developed to adapt to different experimental sizes.A user-friendly interface was implemented,which allows converting script language expressions into FPGA internal control parameters.The proposed digital system can be combined with a conventional analog data acquisition system to provide more flexibility.The performance of the combined system was veri-fied using experimental data.

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.

Digital仿真测试在改进数字逻辑课程教学中的应用探究--基于与Logisim软件的比较

针对数字逻辑课程教材中的一处错误,提出使用Digital仿真软件进行测试的改进方案。分析表明:Digital仿真软件能用于组合逻辑电路与时序逻辑电路的测试;其不仅可使用真值表实现测试,还可用测试语句构建大规模的复杂测试用例,更适用于数字逻辑课程教学中设计题目的测试。进一步与Logisim软件比较表明:Digital软件测试功能更强,波形观察方便,更有助于实验和测试;考虑了电源和接地、外接端子均为双向连接,Digital软件所构建和仿真的电路更加符合实际;其RAM器件类型更多,有助于仿真完整的计算机系统。据此提出,在数字电路和计算机组成原理等硬件课程教学中推广使用Digital软件。