What is a Data Encryption Standard?

Data Encryption Standard is an early data encryption method containing the symmetric key algorithm for encrypting electronic data. It is an insecure and outdated method of data encryption which uses the same key to encrypt and decrypt a message. It was developed in the early 1970s and has a great influence on developing modern cryptography.

How are Data Encryption Standards Used?

In 1973, the National Bureau of Standards (now the National Institute of Standard and Technology) issued a notice inviting proposals for a crypto algorithm that can be considered to be the data encryption standard. No viable proposals were received at the first attempt. 

In 1974, National Bureau of Standards issued a second notice inviting the same and International Business Machines Corporation (IBM) came up with Lucifer algorithm. National Bureau of Standards and U.S. National Security Agency reviewed the algorithm and made some modification in consultation with IBM. 

Then it was endorsed as the Data Encryption Standard. In the following years, it became mandatory to use the DES algorithm for all electronic financial transactions of the U.S. government. 

All the nations started using DES as the standards organizations adopted it worldwide and it became the international standard for business and commercial data encryption. 

DES is a block cipher, here a cryptographic key and algorithm are applied to a block of data simultaneously and not one bit at a time. DES groups a text into 64-bit blocks. 

A secret key enciphers each block into 64-bit ciphertext by transposition and substitution. It involves 16 iterations and can run in four different modes. The key controlling the transformation consists of 64 bits, the user can choose only 56 of those. 

These 56 are actually the key bits, the remaining are parity check bits. Decryption is the inversion of the encryption, following the steps in reverse order. In the beginning of 21st century, the DES was replaced by a more secure encryption standard named Advanced Encryption Standards.