Serpent Encryption

Serpent is a symmetric key block cipher that was a finalist in the Advanced Encryption Standard (AES) competition.

Key Generation

Generate a secure key and initialization vector (IV) for Serpent encryption

Encrypt File

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Decrypt File

Upload an encrypted file and decrypt it with Serpent

About Serpent Encryption

Serpent is a symmetric key block cipher designed by Ross Anderson, Eli Biham, and Lars Knudsen. It was a finalist in the Advanced Encryption Standard (AES) competition, ultimately coming in second to Rijndael (which became AES).

Key Features:
  • Block Size: 128 bits
  • Key Sizes: 128, 192, or 256 bits
  • Structure: Substitution-permutation network (SPN)
  • Rounds: 32 rounds (compared to AES's 10-14 rounds)
  • Security Margin: Designed with a very high security margin, prioritizing security over performance
How Serpent Works:
  1. Initial Permutation: The input block is rearranged according to a fixed pattern.
  2. Round Function (32 times):
    • Key mixing: XOR with round key
    • S-box substitution: Non-linear substitution using 8 different 4-bit S-boxes
    • Linear transformation: Mixing of bits to provide diffusion
  3. Final Permutation: The inverse of the initial permutation is applied.
Advantages of Serpent:
  • High Security Margin: With 32 rounds, Serpent has a much higher security margin than AES.
  • Conservative Design: Uses well-understood cryptographic principles and avoids complex mathematical structures.
  • Resistance to Attacks: No practical attacks have been found against the full 32-round version.
  • Bit-slice Implementation: Can be efficiently implemented using bit-slicing techniques on modern processors.
Comparison with AES:
Feature Serpent AES (Rijndael)
Block Size 128 bits 128 bits
Key Sizes 128, 192, 256 bits 128, 192, 256 bits
Rounds 32 10 (128-bit), 12 (192-bit), 14 (256-bit)
Performance Slower Faster
Security Margin Higher Lower
Note: While Serpent was not selected as the AES standard, it remains a highly secure cipher and is used in various security applications, particularly those requiring a high security margin. It is often used in disk encryption software like TrueCrypt and VeraCrypt.