Osama Almasri, Hajar Mat Jani
Abstract: International Data Encryption Algorithm (IDEA) is one of the encryption algorithms that is widely used for security purpose. IDEA block cipher operates with 64-bit plain text block and 64-bit cipher text block, and a 128-bit key controls it. The fundamental design of the algorithm is using three different algebraic operations: bitwise Exclusive OR, multiplication modulo, and addition modulo. Having the largest number of weak keys is one of the drawbacks of IDEA. In addition, a new attack during round six of IDEAs operations has been detected. In this paper, we propose and describe the new design and preliminary implementation of a more secure encryption algorithm based on IDEA, and it is named DS-IDEA. Increasing the size of the key from 128 bits to 512 bits will increase the complexity of the algorithm. The algorithms complexity is increased by increasing the amount of diffusion (multiplicative additive block) in a single round. It is implemented to provide better security to the users password within the Online Password Management System (OPMS) in order to protect the users data within the database from hackers and other forms of unauthorized access.
Keywords: International Data Encryption Algorithm IDEA, Double Secure-IDEA DS-IDEA, Multiplicative Additive MA, Online Password Management System OPMS