Hawkynt

Rail Fence Cipher

Classical transposition cipher writing plaintext diagonally on successive rails of imaginary fence, then reading horizontally. Simple zigzag pattern with configurable number of rails. Easily broken by brute force due to limited key space.

Properties

Property	Value
Category	Classical Ciphers
Sub-category	Classical Cipher
Security status	🎓 Educational Only
Complexity	Beginner
Inventor	Unknown (Classical)
Year	1800
Origin	🇺🇸 United States
Source	algorithms/classical/railfence.js

Security

Status: 🎓 Educational Only

Known vulnerabilities

Issue	Description	Mitigation
Very limited key space (number of rails), easily brute forced even by hand	—	None - cipher is fundamentally insecure
Character frequencies preserved, making statistical analysis possible	—	Use only for educational demonstrations

Documentation

• Wikipedia Article
• Educational Tutorial
• Cryptii Implementation

References

• Practical Cryptography
• GeeksforGeeks Tutorial
• Educational Implementation

Test vectors

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

Vector 1 — Classic rail fence example with 3 rails

Field	Value
key	33
input	5745415245444953434f5645524544464c454541544f4e4345
expected	574543524c5445455244534f45454645414f4341495644454e

Vector 2 — Educational example with 4 rails

Field	Value
key	34
input	41545441434b41544441574e
expected	4141544b544e544344574141

Vector 3 — Simple 2 rail example

Field	Value
key	32
input	48454c4c4f
expected	484c4f454c

Vector 4 — Mixed case with spaces

Field	Value
key	33
input	48656c6c6f20576f726c64
expected	486f72656c206f6c6c5764

Vector 5 — Long message with 5 rails

Field	Value
key	35
input	544845515549434b42524f574e464f58 4a554d50534f5645525448454c415a59 444f47
expected	54424a5244484b5258554554594f4543 4f4f4d56485a4751495746504f454155 4e534c

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