Cryptanalysis of Jain-Singh’s identity-based RSA encryption

Abstract

Identity-based Encryption (IBE) solves the problem of requiring key certificates in Public Key Encryption (PKE) by replacing the public key with the user’s identity. However, most IBE systems depend on Elliptic Curve Cryptography (ECC) which makes them time inefficient. Since Adi Shamir presented the idea of IBE, designing an IBE using an efficient encryption algorithm such as RSA still remains an open challenge. In 2017, Jain and Singh presented an identity-based variant of RSA. They claimed that their system is secure without any more computational overhead. In this paper, we analyze the security of Jain Singh’s identity-based RSA encryption. We launch two attacks against their system and prove that their system is not secure.