Key Schedule Algorithm using 3-Dimensional Hybrid Cubes for Block Cipher

A key scheduling algorithm is the mechanism that generates and schedules all session-keys for the encryption and decryption process. The key space of conventional key schedule algorithm using the 2D hybrid cubes is not enough to resist attacks and could easily be exploited. In this regard, this research proposed a new Key Schedule Algorithm based on coordinate geometry of a Hybrid Cube (KSAHC) using Triangular Coordinate Extraction (TCE) technique and 3-Dimensional (3D) rotation of Hybrid Cube surface (HCs) for the block cipher to achieve large key space that are more applicable to resist any attack on the secret key. The strength of the keys and ciphertext are tested using the Hybrid Cube Encryption Algorithm (HiSea) based on Brute Force, entropy, correlation assessment, avalanche effect and NIST randomness test suit which proves the proposed algorithm is suitable for the block cipher. The results show that the proposed KSAHC algorithm has performed better than existing algorithms and we remark that our proposed model may find potential applications in information security systems.