Quantum Analysis of LESCA
Sumanta Chakraborty, Debajyoti Mandal, SK Hafizul Islam · 2025
This paper explores the complexity measurements of applying Grover's search algorithm on a dynamic, key-dependent, lightweight stream cipher, LESCA (LightwEight Stream Cipher Algorithm). For this purpose, we present our algorithms to implement LESCA in quantum paradigm, probably the first, to the best of our knowledge. After that, we provide the cost measurements of the quantum implementation of LESCA and the quantum cost for applying Grover's search on LESCA. We show that LESCA meets the quantum security levels 1, 3, and 5 defined by National Institute of Standards and Technology (NIST).