Hawkynt

Enigma Machine

Simplified 3-rotor Enigma machine simulation for educational purposes. Historical WWII cipher machine with rotating mechanical rotors and electrical pathways. Uses reciprocal substitution through rotor wirings and reflector. Input domain: uppercase A-Z only. The machine is 26 keys, 26 lamps and 26 rotor contacts - it has no key for a digit, a space, a punctuation mark or a lowercase letter, and operators spelled such things out in the plaintext before enciphering. Anything outside A-Z is therefore refused by name and position rather than case-folded or passed through in clear, and A-Z round-trips exactly because the machine is reciprocal.

Properties

Property	Value
Category	Classical Ciphers
Sub-category	Classical Cipher
Security status	🎓 Educational Only
Complexity	Expert
Inventor	Arthur Scherbius
Year	1918
Origin	🇩🇪 Germany
Restricted input domain	Yes
Source	algorithms/classical/enigma.js

Security

Status: 🎓 Educational Only

Known vulnerabilities

Issue	Description	Mitigation
No letter can encrypt to itself due to reflector design, reducing key space	—	Historical design flaw - avoid for real cryptography
Predictable rotor advancement patterns enable statistical cryptanalysis	—	Educational use only - demonstrates importance of proper design

Documentation

• Wikipedia Article
• Bletchley Park History
• Technical Description

References

• Enigma Simulator
• Educational Implementation
• Historical Analysis

Test vectors

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

Vector 1 — Wikipedia canonical check - rotors I II III left to right, wide B reflector, ring settings A, start AAA, typing AAAAA gives BDZGO

Field	Value
key	414141313233
input	4141414141
expected	42445a474f

Vector 2 — The same check carried on to 25 letters, which crosses the right rotor’s turnover at V and so exercises the middle rotor stepping

Field	Value
key	414141313233
input	41414141414141414141414141414141414141414141414141
expected	42445a474f5743584c544b5342544d43444c50424d55514f46

Vector 3 — Reciprocity - the machine is its own inverse, so the 25-letter ciphertext returns 25 A’s on the same setting

Field	Value
key	414141313233
input	42445a474f5743584c544b5342544d43444c50424d55514f46
expected	41414141414141414141414141414141414141414141414141

Vector 4 — Start position ABC. No published source carries this value; it is here to cover a non-zero start position

Field	Value
key	414243313233
input	48454c4c4f574f524c44
expected	524f4d554c4c42494242

---

← All algorithms

This site is open source. Improve this page.