A Combined Sudoku and Synthetic Colour Image Techniques for Cryptographic Key Generation

Abstract

The exchange of sensitive digital information has increased significantly in the last decade due to the internet’s growth and availability. More robust encryption techniques were introduced to secure the data-in-transit and data-at-rest. The strength of these encryption algorithms depends on the keys. Keys are generated using Pseudorandom Number Generators (PRNG). The key generation algorithm defines these PRNGs. Although there are many robust key generation algorithms, there is a demand for new key generation algorithms to break hackers’ experience and knowledge. This paper proposed a new key generation algorithm using value generated from sudoku matrices and synthetic color image. 8 × 8 sudoku matrices are generated randomly for each session. These sudoku matrices are solved using backtracking and recursive programming. The solved sudoku matrices are used to extract bits from pixels of the synthetic color image. The extracted bits are then combined to form a key. Further, randomness in the key is tested using the NIST (National Institute of Standards and Technology).