Quantum Key Recovery Attack on Simplified Grain 4-Bit Cipher Using Grover's Algorithm
M. Mohankumar, Bhupendra Singh, T. Thamaraimanalan, Santosh Kumar Korada, P Yuvaraj, S Jyothikamalesh · 2024
In this paper, we proposed a simplified version of the Grain-128 stream cipher and developed a corresponding quantum circuit. Leveraging Grover's algorithm, we demonstrate the ability to recover a key given plaintext, initialization vector (IV), and corresponding ciphertext through various methods, including single pair, double pair series, and double pair parallel approaches. Using the Qiskit Quantum Development Kit (QDK), we conduct these attacks and estimate the required quantum resources. Our research reveals that the simplified grain cipher is vulnerable to quantum attacks, showing how quantum computing could affect cryptographic systems.