code
🔐 Code
🇫🇷 Version française : LISEZMOI.md
Two standalone tools (one HTML file each, no library, no installation). User interfaces in French.
| Tool | Launch |
|---|---|
| Multi-Cipher Cracker v3.24.0 | ▶️ multi_cipher_v3_24_0.html |
| Cryptographic battleship v6 | ▶️ bataille_navale_v6.html — manual (French): BATAILLE NAVALE CRYPTOGRAPHIQUE V6.rtf |
Multi-Cipher Cracker
Automatic cryptanalysis of classical ciphers: the tool analyses the ciphertext, preselects the plausible ciphers, runs the matching attacks in parallel and ranks the candidate plaintexts by linguistic likelihood (French and English). Works offline, including from file://: language models and word lists are embedded in the file in compressed form.
Usage
- Open the link above (Chrome / Edge 90+, Firefox 113+, Safari 16.4+) and wait for “Prêt” (ready).
- Paste the ciphertext, or a section file (template provided in the tool, opened on Kryptos K4), or pick an example.
- DÉCODE: simple encodings only. CRACK: cryptanalysis of the ticked ciphers. STOP halts everything; results already found stay displayed.
Features
| Feature | Description |
|---|---|
| Section file | [CIPHERTEXT], [KNOWN_PLAINTEXT] / [KNOWN_COMBINATIONS] (“Position a-b : WORD”, base 0 and 1 tested), [INFO], # lines; template that can be copied for an AI |
| Analysis | Index of coincidence, symbol counts, diagnosis, likely key lengths (click = force) |
| Preselection | Ciphers ticked automatically from the text: encoding, number groups, ADFGVX, symbols, length, IC, χ², digrams, known plaintext |
| Direct decoders | Base64, Base32, hex, binary, decimal / octal ASCII, ROT13, ROT47, Atbash, reverse, executed Brainfuck; chained up to 3 layers; FLAG{…} flag brought to the top 🚩 |
| Monoalphabetic | Caesar, Bi-ROT, Atbash, Affine, Reverse, Substitution (letters or symbols) |
| Homophonic | Homophonic (Zodiac Z408 solved), symbol-words (nomenclator), null symbols, codes in number groups |
| Polyalphabetic | Vigenère, Beaufort, variant Beaufort, Porta, Gronsfeld, Autokey, Quagmire I to IV; known key, hints, CTF list, word list, brute force 1 to 7 letters; known plaintext imposed per column |
| Digraphic and fractionating | Playfair, Two-Square, Four-Square, Bifid, Hill 2×2, ADFGX / ADFGVX, Nihilist, Two 5×5 tables + seed (keyword or free) |
| Transpositions | Rail Fence, simple, inverse and double Columnar; grid transposition (rotations, serpentines, diagonals, spiral, period, toroidal diagonal); 3D block transposition |
| W segments | “W = separators” option (W and line breaks), per-segment view with known plaintext per column |
| Views | Grid (PNG export), isometric SVG 3D block (hover, path, PNG export), period chart, symbol palette |
| Results | Streamed, best first, expandable; continuous line + line split into words; minimum score 15 % |
| Session | Export / import, built-in examples (including Z408 and Z340), “?” help on every control |
| Self-test | Also started by ?selftest in the URL |
Method
- Single score: mean quadgram log-likelihood, calibrated per language (0 % = random, 100 % = real text); pentagrams and plaintext entropy for homophonic ciphers; word list for refinement and word splitting.
- Polyalphabetic: χ² per column then optimisation of each key letter, plus whole keys tested; a key is kept only if the plaintext contains real words.
- Simulated annealing (substitution, homophonic, Playfair, Bifid, squares, double columnar, two tables) spread over a pool of Web Workers (logical threads − 1); workload split into blocks (brute force, dictionary, widths, seeds); “∞” duration until STOP.
- Proof of reading and stop: null model (random text with the language’s letter frequencies); a plaintext is proven if the chance probability of its words × keys tested < 10⁻⁸; enumeration stops at the first proven plaintext, annealing is confirmed by two agreeing seeds.
- Data: complete FR/EN quadgrams, FR/EN pentagrams (11.9 M entries) decompressed on demand; Gutenberg corpora (20 French, 27 English books); FrequencyWords 30,000-word lists (H. Dave, CC BY-SA 4.0); Z408 / Z340 (zodiackillerciphers.com, K. Gorman).
Test set: jeu de test.txt (one ciphertext per method, with its key). The detailed version history (2.7 → 3.24.0) is in the header block of multi_cipher_v3_24_0.html.
Cryptographic battleship
26 × 26 battleship for two players, peer to peer in the browser.
| Feature | Description |
|---|---|
| Connection | WebRTC on a LAN, or over the Internet through public STUN servers; connection codes exchanged by copy-paste (SMS, mail…) |
| Challenge | Each player’s password is encrypted by the position of their fleet: SHA-256(grid + timestamp + nonce1 + nonce2); it is revealed only by sinking the whole fleet |
| Anti-replay | Timestamp and nonces unique to each game |
| Fleet | 5 ships, 17 cells, random automatic placement |
| Special weapons | Bomb (aircraft carrier, 5-cell cross), torpedo (submarine, whole line), radar (destroyer, distance) |
Only network access: the STUN servers, in WAN mode.
License
MIT
Author
Eric PERRET — GitHub — www.azs.fr