DES Data Encryption Standard-preliminary understanding

Des Data Encryption Standard

Data Encryption Standard (DES) is a block password encrypted with a key. It is based on a symmetric algorithm that uses a 56-bit key. Des is no longer a secure encryption method, mainly because it uses 56 as the key is too short. To provide practical security, you can use the derived algorithm 3DES of des for encryption, although 3DES also has a theoretical attack method. In 2001, Des was replaced by Advanced Encryption Standard (AES. In addition, des is no longer a standard of the National Standards Institute of Science and Technology.

Encryption Principle

Des uses a 56-bit key and an additional 8-bit parity bit to generate a maximum of 64-bit grouping size. This is an iterative group password, using the technology known as feistel, where the encrypted text block is divided into two halves. Use the sub-key pair to apply the loop function in half of them, and then perform the "XOR" Operation on the output and the other half; then switch the two half, the process continues, but the last loop is not exchanged. Des uses 16 cycles, exclusive or, replacement, replacement, and shift operations.

3DES

A common variant of DES is threefold des, a mechanism that uses a 168-bit key to encrypt data three times; it generally (but not always) provides extremely powerful security. If the three 56-bit sub-elements are the same, the Triple DES is backward compatible with DES.

Features

Des is a symmetric encryption algorithm that uses the same key for encryption and decryption.

1. Supports encryption and decryption of strings of any length
2. Plaintext and key can be less than 8 bytes
3. Supports line breaks, tabs, and other special characters.
4. You can select three display modes for ciphertext.
5. Support for three des
6. Supports file encryption and decryption
7. Progress displayed during encryption

Program

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