Hawkynt

THX (Twofish Extended)

Educational extended Twofish with 256/512/1024-bit keys and proportional rounds (16/20/24). Based on Twofish structure with simplified key schedule for learning.

Properties

Property	Value
Category	Block Ciphers
Sub-category	Extended Block Cipher
Security status	🎓 Educational Only
Complexity	Expert
Inventor	Educational Variant (Based on Schneier Twofish)
Year	2025
Origin	Not specified
Source	algorithms/block/thx.js

Parameters

Parameter	Supported values
Key sizes	32 bytes (256 bits); 64 bytes (512 bits); 128 bytes (1024 bits)
Block sizes	16 bytes (128 bits)

Security

Status: 🎓 Educational Only

Known vulnerabilities

Issue	Description	Mitigation
Educational Implementation	This is an educational extension of Twofish, not suitable for production use	Use only for learning cryptographic principles and algorithm design

Documentation

• Original Twofish Specification
• Extended Block Cipher Design
• Educational Cryptography

References

• Twofish Official Paper
• Block Cipher Theory
• Feistel Networks

Test vectors

2 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.

Vector 1 — THX-256 Zero Test Vector

Source: Educational implementation test

Field	Value
key	0000000000000000000000000000000000000000000000000000000000000000
input	00000000000000000000000000000000
expected	5ff7e9c66d38a276b84a464d10414c65

Vector 2 — THX-256 Pattern Test Vector

Source: Educational implementation test

Field	Value
key	fedcba9876543210fedcba9876543210fedcba9876543210fedcba9876543210
input	0123456789abcdef0123456789abcdef
expected	2f35f89793d1c8d72e1858a67092f87f

---

← All algorithms

This site is open source. Improve this page.