An Estimation of Exponential Sums Associated with a Cubic Form Polynomial

The method of exponential sums is one of a few general methods enabling us to solve a wide range of miscellaneous problems from the theory of numbers. The main problem of the theory of exponential sums is to obtain an upper estimate of the modulus of an exponential sum as sharp as possible. Investigation on the sums when f is a two-variable polynomial is studied using the Newton polyhedron technique. One of the methods to obtain the estimate for the above exponential sums is to consider the cardinality of the set of solutions to congruence equations modulo a prime power. A closer look on the actual cardinality on the following polynomial in a cubic form f(x,y) = ax3 + bxi + cx + dy + e has been carried out using the Direct Method with the aid of Mathematica. We reveal that the exact cardinality is much smaller in comparison with the estimation. The necessity to find a more precise estimate arises due to this big gap. By a theorem of Bezout, the number of common zeros of a pair of polynomials does not exceed the product of the degrees of both polynomials. In this research, we attempt to find a better estimate for cardinality by looking at the maximum number of common zeros associated with the partial derivatives fx(x,y) and fy(x,y). Eventually a sharper estimate of cardinality for the various conditions on the coefficients of f(x,y) can be determined and the estimate of S(f; p') obtained

Secure Cryptographic E-Auction System

The evolution of the auction market has been on the upswing throughout the years as technology evolves at an accelerating rate. With the advanced technology nowadays, digital transformation has been applied to the auction markets as a means of transferring goods or services in an online form. Electronic auctions enable sellers to reach a broader range of prospective bidders and participate in the auctions anywhere-anytime. Nevertheless, the security aspects of the e-auction system have become the main concerns for the parties involved. Hence, a secure cryptographic electronic auction system is proposed by employing the underlying cryptographic schemes as the building blocks, namely, asymmetric encryption, digital signature scheme, and hash functions. The proposed e-auction system fulfills the security requirements, encompassing anonymity, correctness, confidentiality, privacy, integrity, and fairness. Performance analysis has also been performed on our proposed e-auction system

Notes on two flawed attacks on undeniable signature schemes

In Eurocrypt 2005, Kurosawa and Heng proposed a set of 3-move witness indistinguishable protocols to be incorporated in the confirmation and disavowal protocols of the FDH variant of undeniable signature schemes. Their 3-move protocols gave rise to the development of many other variants of undeniable signature schemes. In 2010, Zhou, Zhang and Li showed a weakness in Kurosawa and Heng's proof system which enables a malicious prover to impersonate the signer. Libert and Quisquater proposed the first identity-based undeniable signature scheme. In 2007, Li et al. proposed a universal forgery attack on their scheme. In this paper, we show that both of the attacks which were proposed on Kurosawa and Heng's proof system and Libert and Quisquater's scheme have fatal errors, and therefore, both claims are false

Identity-based identification without random oracles

This paper shows identity-based (ID-based) identification schemes which are provably secure in the standard model. The schemes are derived from Boneh-Boyen signature scheme, a signature scheme which is provably secure in the standard model based on the strong Diffie-Hellman assumption. More precisely, we present two canonical schemes, namely, a scheme which is secure against impersonation under passive attack, and a scheme which is secure against impersonation under active and concurrent attacks

The insecurity of a certificateless undeniable signature scheme

Duan proposed the first certificateless undeniable signature scheme in 2008. Later in 2012, Zhao and Ye proffered an efficient scheme which enjoys from a pairing-free sign algorithm. In this paper, we prove the insecurity of their efficient scheme by mounting two attacks on its invisibility and non-impersonation. In addition, we propose an improved scheme that addresses both of the above attacks while providing better flexibility and additional features for the signer

Blockchain-Based Image Sharing Application

The major drawback of a centralised system is using a shared database among the network users. If a server failed to operate, then the whole system will be affected. Leakage of sensitive data such as name of user, home address and contact number is a big issue faced by most networking sites. In this research, a blockchain-based image sharing web application will be developed which makes the process of exchanging image more secure and reliable. Upon launching the application, users are strongly encouraged to publish their original image. Users can view all the published images on news feed. Besides, users are allowed to update their profile by changing the avatar and description of user profile. Since all images are stored by using InterPlanetary File System (IPFS), hence a little capacity is needed to save the related Uniform Resource Locator (URL) for retrieval purpose

A Blockchain-Based E-Voting System

E-voting methods have become increasingly popular in recent years due to the rapid growth of internet and computer networks. Many e-voting schemes have been proposed by researchers that use cryptographic tool such as blind signature technique and homomorphic encryption technique. However, most of these proposed schemes use a centralised database as their data storage medium and it causes various security risks, such as data alteration by a third-party in the network due to the use of central database system. Therefore, it is a need to have a trusted entity to manage the voting process. This brings the involvement of blockchain technology in this proposed e-voting scheme which can provide a decentralised model that makes the network flexible, reliable and able to support real-time services. This study focuses on the development of a secure blockchain-based e-voting system. Finding shows that the proposed scheme is secure and efficient as it outperforms some of the existing schemes with respect to transaction cost

Authentication for 5G Mobile Wireless Networks

Discussions regarding 5G mobile wireless networks frequently involve the impact they will create to our daily lives. Some view 5G as a disruption while some are questioning the need to deploy the network when conventional mobile networks are still performing optimally. The economic and lifestyle impact of 5G is rather subjective, but it is definite that there will be consequences to the security and privacy discussion sphere with an emphasis on authentication. As it arrives with new mechanisms, there is certainly a whole new attacking avenues to be capitalised. This paper surveys the state of 5G mobile wireless networks in terms of authentication. It further discusses the security features and challenges in the 5G mobile wireless networks, and future directions will also be charted