DES/3DES Encryption/Decryption
Classic symmetric encryption tool supporting text and file processing
About DES/3DES
DES (Data Encryption Standard) is a symmetric-key algorithm for the encryption of digital data. Due to its short key length (56 bits), it is now considered insecure. 3DES (Triple DES) applies the DES algorithm three times to each data block, increasing security, but has been superseded by AES.
Although not recommended for new systems, DES/3DES is still widely used in legacy systems.
Key Features
- Supports DES and 3DES (TripleDES).
- Supports CBC, ECB, CTR, CFB, OFB modes.
- All Local: Computations happen in your browser; no data is sent to servers.
- Supports text and file encryption/decryption.
Modes of Operation
- CBC: Most common, requires IV, secure.
- ECB: Simplest, no IV, but insecure (pattern leakage). Not recommended.
- CTR: Turns block cipher into stream cipher.
- CFB: Self-synchronizing stream cipher.
- OFB: Synchronous stream cipher.
DES vs 3DES Comparison
| Algorithm | Key Length | Block Size | Security | Speed | Recommendation |
|---|---|---|---|---|---|
| DES | 56-bit (8 bytes) | 64-bit | Low - Vulnerable to brute-force | Fast | Legacy compatibility only |
| 3DES-2Key | 112-bit (16 bytes) | 64-bit | Medium | Medium | Recommended for legacy systems |
| 3DES-3Key | 168-bit (24 bytes) | 64-bit | High | Slow (3x DES) | Recommended for legacy systems |
Security Note
- DES is broken. Use AES for sensitive data.
- 3DES is slower and less secure than AES.
- Keep your Key and IV secret.
- Avoid ECB mode unless necessary.
- Always use a random, unique IV for each encryption.
Use Cases
- Legacy system maintenance (banking/payment)
- Decrypting old database fields
- Educational purposes
- Simple obfuscation
FAQ
Difference between DES and 3DES?
DES uses a 56-bit key and is vulnerable to brute-force. 3DES applies DES three times with up to three keys, offering better security but slower performance.
Why is the decrypted output garbled?
Likely due to: 1. Wrong Key/IV; 2. Wrong Mode (CBC/ECB); 3. Wrong Padding; 4. Wrong Input Format (Hex vs Base64).
Why no IV for ECB?
ECB encrypts each block independently without chaining, so no initialization vector is needed. This makes it insecure as it reveals data patterns.
Which padding to choose?
Pkcs7 (often called PKCS5Padding) is the standard. ZeroPadding fills with null bytes.
Can this tool decrypt any file?
Only if you have the mathematically correct Key, IV, Mode, and Padding.