XTEA Encryption

XTEA (eXtended TEA) is a block cipher designed to correct weaknesses in the TEA algorithm.

Key Generation

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

Encrypt File

Upload a file and encrypt it with XTEA

Decrypt File

Upload an encrypted file and decrypt it with XTEA

About XTEA Encryption

XTEA (eXtended TEA) is a block cipher designed by David Wheeler and Roger Needham of the Cambridge Computer Laboratory in 1997. It was designed to correct weaknesses in the original TEA (Tiny Encryption Algorithm) cipher.

Key Features:
  • Block Size: 64 bits
  • Key Size: 128 bits
  • Rounds: Typically 32 or 64 rounds
  • Structure: Feistel network
  • Operations: Uses simple operations like addition, XOR, and bit shifts
  • Code Size: Very compact implementation (hence "Tiny")
How XTEA Works:
  1. The 64-bit block is divided into two 32-bit halves (L and R).
  2. For each round:
    • L is modified based on R, a round constant, and the key
    • L and R are swapped
  3. The round function uses a combination of:
    • Addition modulo 2^32
    • Bitwise XOR
    • Left and right shifts
  4. After all rounds, the two halves are combined to form the output block.
Improvements over TEA:
  • Key Schedule: XTEA uses a more complex key schedule to address weaknesses in TEA.
  • Related-Key Attacks: XTEA is more resistant to related-key attacks than TEA.
  • Equivalent Keys: TEA had an issue where different keys could produce identical encryption results; XTEA addresses this.
Security and Applications:
  • Security: XTEA is considered reasonably secure for many applications, though it has some known weaknesses:
    • Related-key attacks (though improved over TEA)
    • Differential cryptanalysis with many chosen plaintexts
  • Applications: XTEA is used in:
    • Resource-constrained environments (embedded systems, microcontrollers)
    • Applications where code size is critical
    • Situations where a simple, easy-to-implement cipher is needed
  • Variants: XXTEA (Corrected Block TEA) is a further improvement that operates on variable-length messages as a single block.
Note: While XTEA is useful in resource-constrained environments, modern applications with sufficient resources should consider using more thoroughly analyzed ciphers like AES for sensitive data.