An encryption - authentication algorithms developed from the elgamal cryptosystem

The paper proposes encryption - authentication algorithms developed from the Elgamal cryptosystem. There are algorithms included: system parameters, keys, encryption, and authenticated decryption. New proposed algorithms ensure a level of security against attacks: revealing secret keys - compared with RSA, GOST; security - compare with ElGamal; anti-forgery. Simultaneously verify the origin of e-doc and ensure the sender's authentication.

Improved cryptanalysis of a ElGamal Cryptosystem Based on Matrices Over Group Rings

ElGamal cryptosystem has emerged as one of the most important construction in Public Key Cryptography (PKC) since Diffie-Hellman key exchange protocol was proposed. However, public key schemes which are based on number theoretic problems such as discrete logarithm problem (DLP) are at risk because of the evolution of quantum computers. As a result, other non-number theoretic alternatives are a dire need of entire cryptographic community.In 2016, Saba Inam and Rashid Ali proposed a ElGamal-like cryptosystem based on matrices over group rings in ‘Neural Computing & Applications’. Using linear algebra approach, Jia et al. provided a cryptanalysis for the cryptosystem in 2019 and claimed that their attack could recover all the equivalent keys. However, this is not the case and we have improved their cryptanalysis approach and derived all equivalent key pairs that can be used to totally break the ElGamal-like cryptosystem proposed by Saba and Rashid. Using the decomposition of matrices over group rings to larger size matrices over rings, we have made the cryptanalysing algorithm more practical and efficient. We have also proved that the ElGamal cryptosystem proposed by Saba and Rashid does not achieve the security of IND-CPA and IND-CCA.

Secure Elgamal Based Authentication Scheme for Cloud Assisted IOT Based Wireless Body Area Network

Now-a-days ireless Body Area Network (WBAN) is considered to be new era technique in which patient’s health record are monitored remotely by using wearable sensors from anywhere in the world. In such high-level communication, there is need of security services are required to protect the data being used by healthcare professionals and patients from intruders or attackers. Therefore, many researchers are showing their keen interest for security enhancement of WBAN architecture for secure communication. In this dissertation work, different security and privacy techniques are reviewed and analysed WBAN/IoT challenges as well their limitations based on the latest standards and publications. This research also covers the state-of-art security measures and research in WBAN. This research presents an ElGamal cryptosystem and biometric information authentication scheme for WBAN/IOT applications. This work observed that most of the authentication protocols using hash function and ElGamal cryptosystem for cloud-based applications are affected by security attacks and are unable to hide the actual identities of the end users during login session. Therefore, this work has introduced a secure biometric ElGamal-based authentication as well as data sharing schemes. The result analysis shows that the proposed work is better with respect to existing work with respect to execution time and cost as well as security level.