Serpent Online Encryption/Decryption
AES finalist algorithm - Ultra-secure block cipher supporting 128/192/256-bit keys
Performance Note
Since Serpent has 32 rounds while AES only has 10-14 rounds, Serpent is slower than AES. For performance-critical applications, consider using AES. Choose Serpent when maximum security margin is your priority.
Key Features
128-bit block size: Same as AES, processes data in 16-byte units
32 rounds of encryption: More rounds than AES (10-14), providing higher security margin
About Serpent Encryption
Serpent is a symmetric key block cipher and one of the five finalist algorithms in the Advanced Encryption Standard (AES) competition. Designed by Ross Anderson, Eli Biham, and Lars Knudsen, it is considered the most conservative design among the finalists.
Although Rijndael (now AES) won the competition primarily for its better performance, Serpent has the highest security margin among all finalist algorithms. It uses a 128-bit block size, supports 128, 192, or 256-bit key lengths, and has 32 rounds of encryption, compared to AES's 10-14 rounds.
Serpent's design prioritizes security over speed, using a substitution-permutation network (SPN) structure. Its conservative design approach and large security margin make it an excellent choice for applications where security is paramount.
Key Features
Encryption Mode Description
Algorithm Comparison
| Algorithm | Key Length | Block Size | Rounds | Security | Speed |
|---|---|---|---|---|---|
| Serpent | 128/192/256 bits | 128 bits | 32 | Excellent | Slow |
| AES | 128/192/256 bits | 128 bits | 10-14 | Excellent | Fast |
| Twofish | 128/192/256 bits | 128 bits | 16 | Excellent | Fast |
AES Competition Background
In 1997, NIST announced a competition to select a new encryption standard to replace DES. Serpent was one of 15 initial candidate algorithms and eventually made it to the final five.
The five finalist algorithms were: Rijndael (winner), Serpent, Twofish, RC6, and MARS. Although Rijndael became AES due to its better performance, Serpent is considered to have the highest security margin.
Many cryptographers recommend using Serpent in applications where security is more important than speed, as its conservative design leaves more room for potential future cryptanalytic attacks.