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.

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 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 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.

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.

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.

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.

Hybrid Dynamic Optimization for Multilevel Security System in Disseminating Confidential Information

Security systems are the need of the hour to protect data from unauthorized access.The dissemination of confidential information over the public network requires a high level of security.The security approach such as steganography ensures confidentiality,authentication,integrity,and non-repudiation.Steganography helps in hiding the secret data inside the cover media so that the attacker can be confused during the transmission process of secret data between sender and receiver.Therefore,we present an efficient hybrid security model that provides multifold security assurance.To this end,a rectified Advanced Encryption Standard(AES)algorithm is proposed to overcome the problems existing in AES such as pattern appearance and high computations.The modified AES is used for the encryption of the stego image that contains the digitally signed encrypted secret data.The enciphering and deciphering of the secret data are done using the Rivest–Shamir–Adleman(RSA)algorithm.The experiments are conducted on the images of the USC-SIPI standard image database.The experimental results prove that the proposed hybrid system outperforms other SOTA(state-of-the-art)approaches.

Robust Threshold Guillou-Quisquater Signature Scheme

The deficiencies of the first threshold Guilbu-Quisquater signature schemepresented by Li-San Liu, Cheng-Kang Chu and Wen-Guey Tzeng arc analysiscd at first, and then a newthreshold Guillou-Quisquater signature scheme is presented. The new scheme isunforgeable and robustagainst any adaptive adversary if the base Guillou-Quisquater signature scheme is unforgeable underthe chosen message attack and computing the discrete logarithm modulo a prime is hard This schemecan also achieve optimal resilience. However, the new scheme does not need the assumption that N isthe product of two safe primes. The basie signature scheme underlying the new scheme is exactlyGuillou-Quisqualtr signature scheme, and the additional strong computation assumption introduced bythe first threshold Guillou-Quisquater scheme is weaken.

A New ID-Based Proxy Blind Signature Scheme

An identity-based proxy blind signature scheme from bilinear pairings isintroduced, which combines the advantages of proxy signature and blind signature. Furthermore, ourscheme can prevent the original signer from generating the proxy blind signature, thus the profitsof the proxy signer are guaranteed. We introduce bilinear pairings to minimize computationaloverhead and to improve the related performance of our scheme. In addition, the proxy blindsignature presented is non-repudiable and it fulfills perfectly the security requirements of a proxyblind signature.

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 Secure and Efficient Signature Scheme for IoT in Healthcare

To provide faster access to the treatment of patients,healthcare system can be integrated with Internet of Things to provide prior and timely health services to the patient.There is a huge limitation in the sensing layer as the IoT devices here have low computational power,limited storage and less battery life.So,this huge amount of data needs to be stored on the cloud.The information and the data sensed by these devices is made accessible on the internet from where medical staff,doctors,relatives and family members can access this information.This helps in improving the treatment as well as getting faster medical assistance,tracking of routine activities and health focus of elderly people on frequent basis.However,the data transmission from IoT devices to the cloud faces many security challenges and is vulnerable to different security and privacy threats during the transmission path.The purpose of this research is to design a Certificateless Secured Signature Scheme that will provide a magnificent amount of security during the transmission of data.Certificateless signature,that removes the intricate certificate management and key escrow problem,is one of the practical methods to provide data integrity and identity authentication for the IoT.Experimental result shows that the proposed scheme performs better than the existing certificateless signature schemes in terms of computational cost,encryption and decryption time.This scheme is the best combination of high security and cost efficiency and is further suitable for the resource constrained IoT environment.

Threshold Subliminal Channel Based on Designated Verifier Signature

The subliminal channel is used to send a secret message to an authorized receiver; the message cannot he discovered by any unauthorized receivers. Designated verifier signature （DVS） provide authentication of a message, we design a DVS scheme with message recovery mechanism and use it as a subliminal channel. In order to share a message among n users securely and allows t or more users can reconstruct the secret in dynamic groups, we combine both subliminal channel and （t, n） threshold cryptography. Then we proposed a threshold subliminal channel which can convey a subliminal message to a group of users based on message-recovery designated verifier signatures. Reconstructing the subliminal message relies on the cooperation of t or more users in the group and they can verify the validity of the subliminal message. Security and performance analysis show that the proposed scheme is secure and efficient.

Generalized Group Signature Scheme

The concept of generalized group signature scheme will be present. Based on the generalized secret sharing scheme proposed by Lin and Harn, a non interactive approach is designed for realizing such generalized group signature scheme. Using the new scheme, the authorized subsets of the group in which the group member can cooperate to produce the valid signature for any message can be randomly specified.

AN EFFICIENT SIGNATURE SCHEME FROM CATALANO’S TRAPDOOR

Digital signature is one of the most important cryptographic primitives. We proposed a new digital signature scheme based on Catalano’s trapdoor. Since Catalano’s trapdoor is more efficient than existing trapdoors in number theory, our scheme need not modular exponentiation but several modular multiplications in the signing algorithm. We also proved our scheme is provably secure against adap-tively chosen message attack by using the Forking lemma.

Threshold Signature Scheme Based on Discrete Logarithm and Quadratic Residue

Digital signature scheme is a very important research field in computer security and modern cryptography. A (k, n) threshold digital signature scheme is proposed by integrating digital signature scheme with Shamir secret sharing scheme. It can realize group-oriented digital signature, and its security is based on the difficulty in computing discrete logarithm and quadratic residue on some special conditions. In this scheme, effective digital signature can not be generated by anyk?1 or fewer legal users, or only by signature executive. In addition, this scheme can identify any legal user who presents incorrect partial digital signature to disrupt correct signature, or any illegal user who forges digital signature. A method of extending this scheme to an Abelian group such as elliptical curve group is also discussed. The extended scheme can provide rapider computing speed and stronger security in the case of using shorter key. Key words threshold scheme - digital signature - discrete logarithm - quadratic residuc - threshold digital signature CLC number TP 309. 7 Foundation item: Supported the National Nature Science Foundation of China, Hubei Province (90104005, 2002 AB0039)Biography: FEI Ru-chun (1964-), male, Ph. D candidate, Associated professor, research direction: information security and cryptography.

Provably Secure Convertible Directed Partially Blind Signatures

Combining the concept of partially blind signature with the concept of directed signature, we introduce a new concept of convertible directed partially blind signature （CDPBS）, in which only the signer and the user can verify, confirm and disavow the validity of given signatures and convert given signatures into universally verifiable ones, to meet the need of signing personally or commercially sensitive messages. We give a formal definition of CDPBS and propose a concrete provably secure CDPBS scheme. The proposed scheme is efficient and secure, in which its unforgeability is the same as that of the Schnorr＇s signature scheme and its untransferability relies on the hardness of the decisional Diffie-Hellman problem. Furthermore, by letting the user＇s private key be a common constant, the proposed scheme can be used as a normal partially blind signature scheme.