Efficient methods to overcome Rabin cryptosystem decryption failure

• Main Authors: Mahad, Zahari, Asbullah, Muhammad Asyraf, Kamel Ariffin, Muhammad Rezal
• Format: Article
• Language: English
• Published: Institute for Mathematical Research, Universiti Putra Malaysia 2017
• Online Access: http://psasir.upm.edu.my/id/eprint/51906/1/2.%20Zahari.pdf; http://psasir.upm.edu.my/id/eprint/51906/; http://einspem.upm.edu.my/journal/fullpaper/vol11sapril/2.%20Zahari.pdf
• Institution: Universiti Putra Malaysia

Rabin cryptosystem is an efficient factoring-based scheme, however, its decryption produces 4-to-1 output, which leads to decryption failure. In this work, in order to overcome the 4-to-1 decryption problem for the Rabin cryptosystem, we propose two distinct methods using the modulus of the type N=p2q coupled with the restriction on the plaintext space M. In the first method, the plaintext space is limited to M ∈ Zpq. For the second method, we restrict the plaintext in the range of M ∈ (0,22n−2). Importantly, we prove that the decryption output of the proposed methods is unique and without decryption failure. The results in this work indicate that the decryption problem of Rabin cryptosystem is overcome.