List of common symmetric encryption algorithms with their block and key size.
| Name | Block Size | Key Size | Notes |
| AES Advanced Encryption Standard | 128 | 128, 192, 256 | Is Rijndael |
| Rijndael | Variable | 128, 192, 256 | Is AES |
| Blowfish | 64 | 32-448 | Often used in SSH |
| DES Data Encryption Standard | 64 | 56 | |
| Triple DES | 64 | 112-168 | DES 3 times |
| IDEA | 64 | 128 | Used in PGP |
| RC4 Rivest Cipher 4 | Stream Cipher | 40-2048 | Insecure/Not used, used in WEP, WPA, and SSL |
| RC5 Rivest Cipher 5 | 32, 64, 128 | 0-2040 | |
| RC6 Rivest Cipher 6 | 128 | 128, 192, 256 | |
| Skipjack | 64 | 80 | Developed by the NSA and supported key escrow |
| CAST-128 | 64 | 40-128 | |
| CAST-256 | 128 | 128, 160, 192, 224, 256 | |
| Twofish | 128 | 1-256 | |
| ChaCha20 | Stream Cipher | 256 | |