Modification of key scheduling for security improvement in XTEA

XTEA algorithm has been used as one of the solutions for securing digital data based on cryptosystem. The algorithm was developed by researchers from the University of Cambridge UK known as a lightweight, low cost and fast algorithm. However, such an attack impossible differential and related-key differential proved able to break through to the XTEA algorithm. XTEA algorithm weaknesses in the key scheduling used to establish the characteristics of the attack so as to find the pieces of the key are used. In this research, security improvement strategies developed by modifying the scheduling algorithm XTEA key into the key dynamic scheduling. This strategy proved to be able to produce different patterns of diffusion of derivative input bits for each use different keys. In addition, the key scheduling modification strategy is capable of producing good-value diffusion bits (over 50% of the total input 64-bit) 10 times more than the original algorithm XTEA. With the level of the round sub key distribution difference reaches 100%, it is certain that the process of guessing the right key value for each round will be very difficult.