DES (Data Encryption Standard) is the first federal symmetric encryption standard developed by IBM in the 1970s and adopted by the National Bureau of Standards (NBS). It is a classic block cipher algorithm that processes plaintext in fixed-length 64-bit blocks.
When using the DES tool for development and debugging, please carefully verify the following parameters:
| Parameter Name | Options/Description | Specification Requirements |
|---|---|---|
| Encryption Mode (Mode) | CBC, ECB, CFB, OFB | ECB is the simplest mode; CBC is more commonly used. |
| Key (Key) | 8 characters / 64 bits | The actual effective length is 56 bits (including 8 parity bits). |
| Initialization Vector (IV) | 8 characters | Required only in modes like CBC, CFB, OFB. |
| Padding (Padding) | PKCS7, ZeroPadding, NoPadding | PKCS7 is currently the most widely used padding method. |
| Character Set (Charset) | UTF-8, GBK | Affects the result of converting plaintext to a binary stream. |
To ensure your data security, understanding the limitations of DES is crucial:
[Image comparing DES and AES encryption key length and block size]
Q: Why can encryption still work when I input a key longer than 8 characters?
A: Standard DES only uses the first 8 characters of the key. If you input a longer string, the system typically automatically truncates it or performs specific processing. To ensure cross-platform compatibility, please strictly use an 8-byte key.
Q: Why does the decryption result show "garbled characters" or "null values"?
A: 1. Check if the encryption mode matches. 2. Check if the padding method is consistent. 3. Check if the Key and IV are correct and if the character set is uniform.
Q: What is 3DES (Triple DES)?
A: Due to the declining security of DES, 3DES enhances security by encrypting data three times using three different keys. It is slower than DES but more secure.
For more detailed knowledge about DES: In-depth Analysis of DES: Structure, Principles, and Security