RC5 Encryption

RC5 is a symmetric-key block cipher designed by Ronald Rivest in 1994, notable for its simplicity and flexibility.

Key Generation

Generate a secure key and initialization vector (IV) for RC5 encryption

Encrypt File

Upload a file and encrypt it with RC5

Decrypt File

Upload an encrypted file and decrypt it with RC5

About RC5 Encryption

RC5 is a symmetric-key block cipher designed by Ronald Rivest in 1994. It is notable for its simplicity and flexibility, with variable parameters including word size, number of rounds, and key size.

Key Features:
  • Block Size: Variable (32, 64, or 128 bits)
  • Key Size: Variable (0 to 2040 bits)
  • Rounds: Variable (0 to 255)
  • Structure: Feistel-like network with data-dependent rotations
  • Operations: Addition, XOR, and rotation
How RC5 Works:
  1. Key Expansion: The variable-length key is expanded into a subkey table
  2. Data-Dependent Rotations: RC5 uses rotations where the rotation amount depends on the data being encrypted
  3. Simple Operations: The algorithm uses only three operations: XOR, addition modulo 2^w, and rotation
Advantages:
  • Simple and elegant design
  • Flexible parameters for different security/performance needs
  • Efficient implementation in both software and hardware
  • Data-dependent rotations provide strong diffusion
Disadvantages:
  • Patented until 2015 (now free to use)
  • Some variants with fewer rounds have been broken
  • Not as widely used as AES in modern applications
Common Parameters:
  • RC5-32/12/16: 32-bit words, 12 rounds, 16-byte (128-bit) key
  • RC5-32/16/16: 32-bit words, 16 rounds, 16-byte (128-bit) key
  • RC5-64/16/16: 64-bit words, 16 rounds, 16-byte (128-bit) key