Private Key Information Research Articles

A Privacy-Preserving V2I Fast Authentication Scheme in VANETs

Due to the characteristics of high-speed movement of vehicles, authentication between vehicles and roadside units (RSUs) needs to be performed quickly. Vehicles can obtain the authentication information of the relevant RSUs from the certification authority (CA) in advance through route planning. Fast authentication can be performed when the vehicle enters the RSU range. However, in most of the current vehicle-to-infrastructure (V2I) fast authentication schemes, when the vehicle requests the authentication information of an RSU from the CA, the vehicle often needs to provide the CA with the travel path information, which leads to the CA easily obtaining the travel path of the vehicle. In addition, the CA encrypts the private keys of RSUs and sends them to vehicles as authentication keys, and the vehicles can obtain the private key information of RSUs directly after decryption. Once the private keys of RSUs are leaked, vehicular ad hoc networks (VANETs) can be attacked by malicious access. In order to protect the confidentiality of RSU private keys and the route privacy of vehicles, we propose a privacy-preserving V2I fast authentication scheme in VANETs. The scheme realizes the confidentiality of RSU private keys and the route privacy protection of vehicles by improving the oblivious transfer (OT) algorithm. Security analysis proves that our scheme has good privacy and attack resistance. Finally, performance evaluation shows that the proposed scheme performs better in terms of computational overhead and communication overhead compared to related schemes.

TWO-FACTOR AUTHENTICATION PROTOCOL IN ACCESS CONTROL SYSTEMS

Background. To ensure the protection of the biometric access control system used in unsecured communication channels, it is necessary to exclude the storage and transfer, transfer of biometric data as well as sequences generated on their basis. The paper proposes a cryptographic protocol of two-factor authentication with the zero-knowledge over the extended field GF(2m) on elliptic curves using biometric data and the private key of the user.
 Objective. The aim of the article is to develop a cryptographic protocol for zero-knowledge two-factor authentication based on elliptic curves using biometric data and the user’s private key, which allows increasing cryptographic strength and reducing the duration of the authentication process.
 Methods. The process of implementing zero-knowledge proof protocols is as follows: one user (proofer) can convince another user (verifier) that he has some secret without disclosing the secret itself.
 Results. A cryptographic protocol for two-factor authentication with zero-knowledge over the extended field GF(2m) of elliptic curves using user biometric data is proposed, which significantly reduces the size of the protocol parameters and increases cryptographic strength (computational complexity of the breaking). There is no leakage of private key information and biometric data of the user during the execution of the zero-knowledge proof protocol.
 Conclusions. The implementation of a cryptographic protocol with zero-knowledge proof two-factor authentication based on elliptic curves allows significantly reducing the size of protocol parameters and increasing the cryptographic strength (computational complexity of the breaking).

Increasing the security of transmitted text messages using chaotic key and image key cryptography

It is critical to safeguard confidential data, especially secret and private messages. This study introduces a novel data cryptography approach. The new approach will be capable of encrypting and decrypting any communication size. The suggested approach will use a sophisticated private key with a convoluted structure. The private key will have 5 components with a double data type to prevent guessing or hacking. The confidential data will produce two secret keys, the first of which will be taken from the image key. These keys will be vulnerable to slight changes in private key information. To maximize the approach's efficiency, the suggested method will deal with lengthy messages by splitting them into chunks. On the other hand, the chaotic logistic map model will be used to create the second key. The suggested technique will be implemented, and several sorts of analysis (sensitivity, quality, security, and speed analysis) will be undertaken to demonstrate the benefits of the proposed method. The quality metrics MSE, PSNR, and CC will be computed to validate the suggested method's quality. To illustrate the efficiency of the proposed technique, encryption and decryption times will be measured, and cryptography throughputs will be determined. Various PKs will be tried throughout the decryption process to demonstrate how sensitive the produced outputs are to changes in the private key. The suggested approach will be tested, and the results will be compared to the results of existing methods to demonstrate the improvement offered by the proposed method.

Secure authentication scheme in 6G‐enabled mobile Internet of things for online English education

In recent years, the mobile Internet of Things (MIoT) for online English education has quickly become an important means and main tool for people to learn and communicate English due it has characteristics and advantages such as high efficiency and no geographical restrictions. However, most MIoT for online English education is vulnerable to security attacks because of the online learning device's weak security protection measures and their communication channels with open wireless nature. To address these issues, herein, a novel secure authentication scheme in 6G-enabled MIoT for online English education is proposed. The proposed authentication scheme does not rely on the ideal tamper-proof device. In this scheme, the certificate and key are updated in real-time to resist side-channel attacks, and pseudonym seeds are used to generate pseudonyms to hide user's identity information and realise identity privacy protection. The scheme allows the attacker to continuously obtain private key information. Detailed security analysis proves that the authors’ scheme is unforgeable to adaptive selection message attacks and can satisfy the security requirements of 6G-enabled MIoT for online English education. In addition, compared with other related studies, the proposed scheme achieves better performance in terms of computation and communication costs.

A modification of the Cayley-Purser algorithm

Cayley- Purser Algorithm is a public key algorithm invited by Sarah Flannery in 1998. The algorithm of Cayley-Purser is much faster than some public key methods like RSA but the problem of it is that it can be easily broken especially if some of the private key information is known. The solution to this problem is to modify this algorithm to be more secure than before so that it gives its utilizers the confidence of using it in encrypting important and sensitive information. In this paper, a modification to this algorithm based on using general linear groups over Galois field $GF(p^n)$, which is represented by $GL_m(GF(p^n))$ where $n$ and $m$ are positive integers and $p$ is prime, instead of $GL_2(Z_n)$ which is General linear set of inverted matrices $2 times 2$ whose entries are integers modulo $n$. This $GL_m(GF(p^n))$ ensures that the secret key of this algorithm would be very hard to be obtained. Therefore, this new modification can make the Cayley-Purser Algorithm more immune to any future attacks.

New Techniques for SIDH-based NIKE

AbstractWe consider the problem of producing an efficient, practical, quantum-resistant non-interactive key exchange (NIKE) protocol based on Supersingular Isogeny Diffie-Hellman (SIDH). An attack of Galbraith, Petit, Shani and Ti rules out the use of naïve forms of the SIDH construction for this application, as they showed that an adversary can recover private key information when supplying an honest party with malformed public keys. Subsequently, Azarderakhsh, Jao and Leonardi presented a method for overcoming this attack using multiple instances of the SIDH protocol, but which increases the costs associated with performing a key exchange by factors of up to several thousand at typical security levels. In this paper, we present two new techniques to reduce the cost of SIDH-based NIKE, with various possible tradeoffs between key size and computational cost.

Multiparty quantum key agreement protocol based on locally indistinguishable orthogonal product states

Based on locally indistinguishable orthogonal product states, we propose a novel multiparty quantum key agreement (QKA) protocol. In this protocol, the private key information of each party is encoded as some orthogonal product states that cannot be perfectly distinguished by local operations and classical communications. To ensure the security of the protocol with small amount of decoy particles, the different particles of each product state are transmitted separately. This protocol not only can make each participant fairly negotiate a shared key, but also can avoid information leakage in the maximum extent. We give a detailed security proof of this protocol. From comparison result with the existing QKA protocols, we can know that the new protocol is more efficient.

Secure and Efficient Signature Scheme Based on NTRU for Mobile Payment

Mobile payment becomes more and more popular, however the traditional public-key encryption algorithm has higher requirements for hardware which is not suitable for mobile terminals of limited computing resources. In addition, these public-key encryption algorithms do not have the ability of anti-quantum computing. This paper researches public-key encryption algorithm NTRU for quantum computation through analyzing the influence of parameter q and k on the probability of generating reasonable signature value. Two methods are proposed to improve the probability of generating reasonable signature value. Firstly, increase the value of parameter q. Secondly, add the authentication condition that meet the reasonable signature requirements during the signature phase. Experimental results show that the proposed signature scheme can realize the zero leakage of the private key information of the signature value, and increase the probability of generating the reasonable signature value. It also improve rate of the signature, and avoid the invalid signature propagation in the network, but the scheme for parameter selection has certain restrictions.

Simple-Yet-Efficient Construction and Revocation of Group Signatures

Group signatures are typically used to authenticate the signer of message while preserving the privacy of the signer. Group signature should be minimized to reduce potential communication overhead. We propose a novel short group signature scheme that generates constant-size group public key and constant-size group signature. The scheme, using pairing-friendly elliptic curves, is efficient in construction. We give the security proof under XDH and ECDL hardness assumptions in the BMW model. Furthermore, we propose two group membership revocation methods which provide revocation information only to verifiers. One revocation method exposes partial private key of revoked users, which requires less revocation information. The other revocation method includes mixed private key information without revealing the real private keys of revoked users. This method is simple in revocation check.

Privacy-Preserving Clustering Using Representatives over Arbitrarily Partitioned Data

The challenge in privacy-preserving data mining is avoiding the invasion of personal data privacy. Secure computa- tion provides a solution to this problem. With the development of this technique, fully homomorphic encryption has been realized after decades of research; this encryption enables the computing and obtaining results via encrypted data without accessing any plaintext or private key information. In this paper, we propose a privacy-preserving clustering using representatives (CURE) algorithm over arbitrarily partitioned data using fully homomor- phic encryption. Our privacy-preserving CURE algorithm allows cooperative computation without revealing users' individual data. The method used in our algorithm enables the data to be arbitrarily distributed among different parties and to receive accurate clustering result simultaneously.

Secure mediated certificateless signature scheme

Ju et al. proposed a certificateless signature scheme with instantaneous revocation by introducing security mediator (SEM) mechanism. This article presents a detailed cryptoanalysis of this scheme and shows that, in their proposed scheme, once a valid signature has been produced, the signer can recover his private key information and the instantaneous revocation property will be damaged. Furthermore, an improved mediated signature scheme, which can eliminate these disadvantages, is proposed, and security proof of the improved scheme under elliptic curve factorization problem (ECFP) assumption and bilinear computational diffie-hellman problem (BCDH) assumption is also proposed.

Network security under siege: the timing attack

Although most encryption algorithms are theoretically secure and remain impervious to even the most sophisticated cryptanalytic techniques, new attacks like the timing attack exploit the engineering side of network security. A timing attack is basically a way of deciphering a user's private key information by measuring the time it takes to carry out cryptographic operations. Factors such as branching and conditional statements, RAM cache hits, processor instructions that run in nonfixed time, as well as performance optimizations to bypass unnecessary operations, all contribute to predictability and therefore to the probability of key decryption.