Study of symmetric-key cryptosystems and implementing a secure cryptosystem with DES

Abstract

The advancements in communication networks and computation over the years have led to a massive volume of data flowing from one place to another. A lot of cryptosystems have been proposed and implemented to keep the channel of communication secure. But with increasingly powerful computers rolling out every day, more and more complicated systems are being built with moderate data overheads to ensure maximum security over the channel. So, in this paper, we briefly discuss the strengths and weaknesses of the three most popular symmetric-key cryptosystems: AES, DES, and 3DES. It has been supported by the various organizations that it with the computers of today, DES can be broken using brute-force attacks in a reasonable amount of time. Given its simple nature of implementation and small key size, we propose a modified implementation of DES to enhance its security with a minimum computational trade-off.