Performing Cryptanalysis on the Secure Way of Communication Using Purple Cipher Machine

Abstract

AbstractGiven the large amount of data that is available, it is vital to protect data. The main goal of cryptography is creating and analyzing methods to keep harmful third parties from gaining access to information transmitted between two entities. Cryptanalysis is the process of attempting to decipher ciphers, cipher text and cryptosystems in order to find any gaps or weaknesses in the systems that could lead to the discovery of the key used to encrypt the data. In this paper, we will investigate the purple cipher machine, a World War II era electromechanical cipher machine used by the Japanese diplomatic service for secure communication before and during WWII. It was considered as one of the hardest machines to crack during the time as a complete machine was never recovered. We present a brief overview of the machine’s internal construction and operation which is primarily controlled by 25-level stepping switches. The internal wiring of the machine displays intricate and complex wiring which made predictions hard. The Purple Machine, which has both encryption and decryption modules, was computer simulated using Python. Finally, for both modules, a time analysis for strings of various sizes is shown and the graph between them is drawn.KeywordsCryptographyPurple machineEncryptionDecryptionCipher