What is the DES algorithm in Information Security?


DES stands for Data Encryption Standard. The Data Encryption Standards (DES) algorithm was invented by IBM in the early 1970s. It obtain the plaintext in 64-bit blocks and changes it into the ciphertext that need the 64-bit keys to encrypt the information. The algorithm need the similar key to encrypt and decrypt the information.

DES is a symmetric key algorithm used to encrypt digital data. Its short key length of 56 bits renders DES too insecure to secure most current applications that is based on encryption.

DES uses block cipher technology to change fixed-length bitstrings into same-sized, encrypted bitstrings. While the standard DES block size is 64 bits, the algorithm can only use 56 of these bits to encrypt information. The other 8 bits are used to provide parity.

DES is a strong encryption standard that works on a 64-bits plaintext block and returns a 64- bits ciphertext. Therefore, DES results in a permutation between the 264 possible arrangements of 64 bits, each of which can be either 0 or 1.

The Data Encryption Standard is being made accessible for use by Federal agencies within the element of a total security program including physical security process, good data management practices, and computer system/network access controls.

Actual input is 64-bits but it can actually need a key of size 56-bits. The least significant bit of each byte is used for parity (odd for DES) or set arbitrarily and does not enhance the security in any way.

It can sequence the blocks from left to right which creates the eighth bit of each byte the parity bit. Because 256 combinations of the keying variable are applicable (and these keying variables can be transformed freely), the algorithm is regarded by some professional to be largely secure.

The two main components of the DES-based system are an algorithm and a key. The DES algorithm is a complex interactive phase includes substitutions, permutations, and mathematical services.

The key feature of DES is that the algorithms is fixed and is public record. However, the actual key is used is shared secret between the creator and the receiver of a transmission.

Advances in DES contains lengthening a key to 128 bits and the multi-pass DES which contains multiple passes usually three of encryption and decryption using several keys.

At its simplest level, the algorithm is nothing more than a set of the two basic techniques of encryption including confusion and diffusion.

The basic constructing block of DES is an individual set of these approaches on the plaintext and depend on the key. This is called a round. DES is based on the Feistel block cipher, known as LUCIFER. It was produced in 1971 by IBM cryptography researcher Horst Feistel. DES needs 16 rounds of the Feistel structure, using a multiple key for each round.

Updated on: 14-Mar-2022

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