Hidden Real Modulus RSA Cryptosystem


  • Getaneh Awulachew’ Zimbele
  • Samuel Asferaw Demilew




Asymmetric key, Cryptography, Data security, Hidden real modulus, Masking, RSA


Cryptographic techniques in cyber security can be categorized into symmetric and asymmetric. Among asymmetric cryptographic techniques, the RSA algorithm is more popular and considered as secured. Since, RSA uses the common modulus in both encryption and decryption, this modulus is openly available for the public which makes it exposed for attack. Its security is based on the assumption of large integer factorization problem, but this could leave it open to different cryptanalysis attacks: low private exponent attack, Shor’s polynomial-time quantum algorithm, quantum inverse Fourier transform and phase estimation.  To address these shortcomings, this paper proposes a public-key security algorithm called Hidden Real Modulus RSA (HRM-RSA) which hides real modulus by masking it. The public mask modulus which is a pseudo random masking number is derived from real modulus. Then, this derived public mask modulus is introduced in a public key component; as a result, a real modulus is kept hidden from the public unlike the case in RSA. Encryption is done using this public mask modulus and the decryption process is done using a private hidden real modulus. For performance analysis Net bean IDE 8.2 is used, and the proposed algorithm is compared with state-of-the-art algorithms: RSA, ESRKGS, and MRSA based on security strength, time complexity, key generation time, encryption speed, and decryption speed. The performance analysis shows that HRM-RSA is less complex but highly secured than existing algorithms. It improves key generation time of ESRKGS, and MRSA by 311%, 42%; encryption time of RSA, ESRKGS, MRSA by 0.7%, 139%, 735%; decryption time of RSA, ESRKGS, MRSA by 3%, 138%, 799%, respectively.


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How to Cite

Zimbele, G. A., & Demilew, S. A. (2023). Hidden Real Modulus RSA Cryptosystem. International Journal of Computing, 22(2), 238-247. https://doi.org/10.47839/ijc.22.2.3094