The DES Algorithm Steps

The DES algorithm is among the most popular symmetric key block ciphers in the world today. It is used for data transmission, storage and authentication. It was invented in the year 1970, but it is still being used as the basis for a variety of modern crypto algorithms. It is also thought to be sufficient and secure to protect bank and payment card transactions.

In DES encryption it begins by transforming the plaintext 64 bits using a series steps, which include initial permutations and rounds of operations. The final permutation takes place. Each step alters bits in various ways, causing confusion and a spread that makes it more difficult for hackers to break the ciphers.

In the initial step, a function known as Initial Permutation (IP) alters the bits of the block into two permuted halves known as Left Plain Text or LPT my explanation and Right Plain Text or RPT. This step changes the order of the original 64-bit plain text, making it more difficult to crack.

After that is completed, the RPT and LPT are joined and run through 16 rounds of DES operations. The final permutation is identical to the original procedure, but reversed.

This makes it very difficult to break the cipher. It is also much faster in hardware than in software, and this speed is a major benefit for certain applications where encryption has to be performed in real-time. Although theoretical attacks have been attempted using DES, the most practical method was a brute force attack that required huge computing resources and still took a long time to complete.