An Elliptic Curve-based Signcryption Scheme with Forward Secrecy

An elliptic curve-based signcryption scheme is introduced in this paper that effectively combines the functionalities of digital signature and encryption, and decreases the computational costs and communication overheads in comparison with the traditional signature-then-encryption schemes. It simultaneously provides the attributes of message confidentiality, authentication, integrity, unforgeability, non-repudiation, public verifiability, and forward secrecy of message confidentiality. Since it is based on elliptic curves and can use any fast and secure symmetric algorithm for encrypting messages, it has great advantages to be used for security establishments in store-and-forward applications and when dealing with resource-constrained devices.Comment: 13 Pages, 5 Figures, 2 Table

Development of Time-Stamped Signcryption Scheme and its Application in E-Cash System

A signcryption scheme combining public key encryptions and digital signatures in one logical step can simultaneously satisfy the security requirements of confidentiality, integrity, authenticity and non-repudiation and with a cost significantly lower than that required by the traditional "signature followed by encryption" approach. This thesis presents a new generic concept of time-stamped signcryption scheme with designated verifiability. Here an authenticated time-stamp is associated with the signcrypted text which can only be verifiable by a specific person, known as the designated verifier. The time-stamp is provided by a trusted third party, namely, Time Stamping System (TSS). The scheme is proved to be secure, as, no one, not even the signcrypter or TSS can produce a valid signcrypted text on behalf of them. We analyzed the security of the proposed scheme and found that it can withstand some active attacks. This scheme is resistant against both inside and outside attacks. The security of our scheme is based upon the hardness of solving Computational Diffie Hellman Problem (CDH), Discrete Logarithm Problem (DLP) and Integer Factorization Problem (IFP). The proposed scheme is suitable in scenarios such as, on-line patent submission, on-line lottery, e-cash, e-bidding and other e-commerce applications. Also we propose an e-cash system based on our proposed time-stamped signcryption scheme which confirms the notion of e-cash securities like anonymity of the spender, unforgeablity of the digital coin, prevention of double spending

Efficient identity based signcryption scheme and solution of key-escrow problem

In cryptography for sending any information from sender to receiver, we have to ensure about the three types of security policies i.e. integrity, confidentiality and authentication. For confidentiality purpose, encryption-decryption technique is used and for authentication purpose digital signature is used, so to ensure this three properties, first sender encrypt the message and then sign the message. Same process done at the receiver end that means first message is decrypted then verified, so it's two step process that increases the communication as well as computation cost. But in many real life applications where more speed and less cost is required like e-commerce applications, we can't use signature then encryption technique, so signcryption is the cryptographic primitives that provides signature as well as encryption at the same time on a single step. First signcryption scheme is proposed by Yullian Zheng in 1997, Since then many signcryption scheme is proposed based on elliptic discrete logarithm problem (ECDLP) , Bilinear pairing, Identity Based and certificateless environment. Many of the Signcryption scheme used Random Oracle Model for their security proofs and few are based on standard model

CGST: Provably Secure Lightweight Certificateless Group Signcryption Technique Based on Fractional Chaotic Maps

In recent years, there has been a lot of research interest in analyzing chaotic constructions and their associated cryptographic structures. Compared with the essential combination of encryption and signature, the signcryption scheme has a more realistic solution for achieving message confidentiality and authentication simultaneously. However, the security of a signcryption scheme is questionable when deployed in modern safety-critical systems, especially as billions of sensitive user information is transmitted over open communication channels. In order to address this problem, a lightweight, provably secure certificateless technique that uses Fractional Chaotic Maps (FCM) for group-oriented signcryption (CGST) is proposed. The main feature of the CGST-FCM technique is that any group signcrypter may encrypt data/information with the group manager (GM) and have it sent to the verifier seamlessly. This implies the legitimacy of the signcrypted information/data is verifiable using the public conditions of the group, but they cannot link it to the conforming signcrypter. In this scenario, valid signcrypted information/data cannot be produced by the GM or any signcrypter in that category alone. However, the GM is allowed to reveal the identity of the signcrypter when there is a legal conflict to restrict repudiation of the signature. Generally, the CGST-FCM technique is protected from the indistinguishably chosen ciphertext attack (IND-CCA). Additionally, the computationally difficult Diffie-Hellman (DH) problems have been used to build unlinkability, untraceability, unforgeability, and robustness of the projected CGST-FCM scheme. Finally, the security investigation of the presented CGST-FCM technique shows appreciable consistency and high efficiency when applied in real-time security applications

A Privacy-Preserving Secure Framework for Electric Vehicles in IoT using Matching Market and Signcryption

The present world of vehicle technology is inclined to develop Electric Vehicles (EVs) with various optimized features. These vehicles need frequent charging which takes a longer time to charge up. Therefore, scheduling of vehicles in charging stations is required. esides, the information of the EVs and its location is also stored by the charging stations and therefore creates a concern of EV privacy. Various researches are going on to solve these problems; however, an efficient privacy-preserving solution is less practiced till date. In this paper, a framework for Electric Vehicle (EV) charging is discussed. The framework uses the concept of Matching Market to identify a charging station and uses the lattice-based cryptography for secure communications. The matching market considers multiple factors to provide the best allocation of charging station and cryptography ensures security and privacy preservation. The use of lattice-based cryptographic hash SWIFFT avoids heavy computation. This usage of matching market and lattice cryptography, more specifically signcryption for EV charging framework are the highlights of the solution and add-ons to the novel features. Overall, the presented framework is efficient in terms of computation and communication cost, satisfaction ratio, slot ratio, charging latency and load balancing index. The performance metrics are compared with recent developments in this field

BINARY EDWARDS CURVES IN ELLIPTIC CURVE CRYPTOGRAPHY

Edwards curves are a new normal form for elliptic curves that exhibit some cryp- tographically desirable properties and advantages over the typical Weierstrass form. Because the group law on an Edwards curve (normal, twisted, or binary) is complete and unified, implementations can be safer from side channel or exceptional procedure attacks. The different types of Edwards provide a better platform for cryptographic primitives, since they have more security built into them from the mathematic foun- dation up. Of the three types of Edwards curves—original, twisted, and binary—there hasn’t been as much work done on binary curves. We provide the necessary motivation and background, and then delve into the theory of binary Edwards curves. Next, we examine practical considerations that separate binary Edwards curves from other recently proposed normal forms. After that, we provide some of the theory for bi- nary curves that has been worked on for other types already: pairing computations. We next explore some applications of elliptic curve and pairing-based cryptography wherein the added security of binary Edwards curves may come in handy. Finally, we finish with a discussion of e2c2, a modern C++11 library we’ve developed for Edwards Elliptic Curve Cryptography