Systematic and Critical Review of RSA Based Public Key Cryptographic Schemes: Past and Present Status

The interconnected digital world is generating enormous data that must be secured from unauthorized access. Advancement in technologies and new innovative methods applied by attackers play an instrumental role in breaching data security. Public key Cryptography provides a set of cryptographic algorithms in achieving data security through confidentiality, integrity and authentication. Among all cryptographic algorithms in general and public key cryptography in particular, RSA is one of the most widely used and applied algorithms. Since its inception, it is commonly being adopted in securing data across different domains such as cloud, image and others. Despite its importance and wide applications, no such systematic and extensive survey exists in the literature. A systematic and thorough study of RSA based cryptography is presented in this work covering several domains. All the available works in this direction are divided into 11 different categories, viz, Hybrid, Parallel, Cloud, Image, Multiple-Keys, Chinese-Remainder-Theorem-based, Digital-Signatures, K-Nearest-Theorem-based, Batch, Wireless, and Core-Modifications. This study methodically explores RSA-based cryptosystems, either modifications in core RSA or applications of enhanced RSA across different domains, systematically categorizing in various categories and eventually providing findings and indications. The current study compares RSA methods based on parameters such as key generation, encryption schemes, decryption schemes, key features and enhancements, and also finds the leading areas where modified RSA has been applied in the recent past. As a result, this study will guide researchers and practitioners in understanding the past and present status of RSA cryptography along with the possibility of its applications in other domains.