| Ku Klux Klan | 1,000 | May 23, 2023, 11:18 a.m. |
| Enigma Messages | 100 | May 14, 2023, 10:36 p.m. |
| The Hutton Cipher – Part 1 | 1,660 | May 6, 2023, 2:20 p.m. |
| Hybrid Encryption I | 1,078 | May 1, 2023, 5:44 p.m. |
| Enigma Part 1 | 1,078 | May 1, 2023, 1:20 a.m. |
| Polyphonic Substitution Cipher — Part 2 | 1,113 | April 10, 2023, 4:46 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 1,111 | April 10, 2023, 4:19 p.m. |
| A Cloaked Substitution Cipher — Part 2 | 1,109 | April 7, 2023, 4:42 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | April 7, 2023, 1:09 p.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,081 | April 7, 2023, 1:24 a.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,109 | April 6, 2023, 9:12 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,080 | April 6, 2023, 4:01 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,080 | April 6, 2023, 3:44 a.m. |
| Double Column Transposition — Part 1 | 1,085 | March 27, 2023, 12:41 a.m. |
| Enigma Part 2 | 1,078 | March 13, 2023, 8:57 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | March 12, 2023, 11:01 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | March 12, 2023, 4:19 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | March 12, 2023, 2:52 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | March 12, 2023, 2:09 p.m. |
| Enigma Combinatorics | 100 | March 12, 2023, 1:10 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | March 12, 2023, 1:22 a.m. |
| Double Column Transposition — Part 2 | 1,086 | March 10, 2023, 12:49 a.m. |
| Double Column Transposition — Part 3 | 1,086 | March 5, 2023, 11:47 p.m. |
| Weakened Granit — Part 1 | 100 | March 4, 2023, 12:45 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | March 2, 2023, 11:59 p.m. |
| Fastest in the West | 1,102 | March 2, 2023, 6:21 p.m. |
| Cascading Encryption — Part 1/3 | 100 | Feb. 25, 2023, 1:55 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Feb. 24, 2023, 9:53 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,078 | Feb. 21, 2023, 3:36 p.m. |
| The Josse Challenge – Part 1 | 1,523 | Feb. 17, 2023, 11:39 p.m. |
| The Einstein Enigma | 1,100 | Feb. 13, 2023, 4:58 p.m. |
| The Syllabary Cipher – Part 5 | 1,252 | Jan. 10, 2023, 4:21 p.m. |
| The Syllabary Cipher – Part 4 | 1,252 | Jan. 10, 2023, 4:21 p.m. |
| The Syllabary Cipher – Part 3 | 1,252 | Jan. 10, 2023, 4:19 p.m. |
| Lightweight Introduction to Lattices — Part 1 | 100 | Jan. 5, 2023, 11:59 p.m. |
| Modular Sequences | 100 | Dec. 30, 2022, 11:15 p.m. |
| Double Columnar Transposition | 100 | Dec. 29, 2022, 4:54 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 101 | Dec. 28, 2022, 9:28 p.m. |
| Strange Message from Thessaloniki | 100 | Dec. 27, 2022, 4:49 p.m. |
| Classical Ciphers^3 | 100 | Dec. 26, 2022, 1:01 a.m. |
| ADFGVX — Part 2 | 100 | Dec. 24, 2022, 10:11 p.m. |
| ADFGVX — Part 1 | 100 | Dec. 24, 2022, 3:29 p.m. |
| New Year's Greetings — Part 4 | 100 | Dec. 23, 2022, 1:32 p.m. |
| New Year's Greetings — Part 3 | 100 | Dec. 23, 2022, 1:19 p.m. |
| New Year's Greetings — Part 2 | 100 | Dec. 23, 2022, 1:06 p.m. |
| M-138 — Part 4 | 1,088 | Dec. 20, 2022, 8:30 p.m. |
| Summer Job | 1,103 | Dec. 16, 2022, 9:17 p.m. |
| RSA: Two different keys — same ciphertext | 1,080 | Dec. 16, 2022, 4:58 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,080 | Dec. 13, 2022, 8:02 p.m. |
| Alice's Birthday Party (Part 2) | 1,079 | Dec. 13, 2022, 6:54 p.m. |
| Alice's Birthday Party (Part 1) | 1,079 | Dec. 13, 2022, 4:59 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,079 | Dec. 13, 2022, 1:52 a.m. |
| ECDH-Key Exchange for Beginners | 100 | Dec. 11, 2022, 6:18 p.m. |
| Factorization Cipher — Part 1 | 100 | Dec. 4, 2022, 3:09 p.m. |
| Spanish Strip Cipher — Part 2 | 1,086 | Nov. 26, 2022, 8:04 p.m. |
| Spanish Strip Cipher — Part 1 | 1,086 | Nov. 26, 2022, 5:40 p.m. |
| M-138 — Part 3 | 1,088 | Nov. 26, 2022, 2:15 a.m. |
| M-138 — Part 2 | 1,088 | Nov. 25, 2022, 11:25 p.m. |
| Polyhomophonic Substitution — Part 3 | 1,119 | Nov. 24, 2022, 6:50 p.m. |
| Wheatstone Cryptograph — Part 1 | 100 | Nov. 22, 2022, 12:36 a.m. |
| Alberti Challenge — Part 1 | 100 | Nov. 21, 2022, 3:56 p.m. |
| Trifid Cipher | 100 | Nov. 21, 2022, 1:10 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Nov. 20, 2022, 9:38 p.m. |
| Hill Cipher with Sudoku Key | 100 | Nov. 19, 2022, 10:20 p.m. |
| Number Sequence — Part 10 | 100 | Nov. 19, 2022, 7:56 p.m. |
| M-138 — Part 1 | 100 | Nov. 13, 2022, 6:02 p.m. |
| An Invisible Message | 100 | Nov. 13, 2022, 1:51 a.m. |
| Polyhomophonic Substitution — Part 2 | 1,120 | Nov. 12, 2022, 10:37 p.m. |
| Homophonic Encryption — Part 2 | 1,110 | Nov. 12, 2022, 11:54 a.m. |
| Homophonic Encryption — Part 1 | 1,110 | Nov. 12, 2022, 11:48 a.m. |
| Homophonic Encryption — Part 4 | 1,110 | Nov. 12, 2022, 11:41 a.m. |
| Homophonic Encryption — Part 3 | 1,110 | Nov. 12, 2022, 11:29 a.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,108 | Nov. 11, 2022, 7:54 p.m. |
| New Year's Greetings — Part 1 | 100 | Nov. 9, 2022, 4:09 p.m. |
| Find the right route — Part 3 | 100 | Nov. 9, 2022, 12:30 a.m. |
| Find the right route — Part 2 | 100 | Nov. 8, 2022, 6:58 p.m. |
| Find the right route — Part 1 | 100 | Nov. 8, 2022, 1:02 a.m. |
| Number Sequence — Part 5 | 100 | Nov. 7, 2022, 10:55 p.m. |
| Pigpen with a twist — Part 1 | 100 | Nov. 7, 2022, 4:47 p.m. |
| Polyhomophonic Substitution — Part 1 | 100 | Nov. 6, 2022, 1:05 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | Nov. 6, 2022, 12:31 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Nov. 5, 2022, 10:19 p.m. |
| The Syllabary Cipher – Part 2 | 1,502 | Nov. 5, 2022, 3:15 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Nov. 4, 2022, 11:01 p.m. |
| The Syllabary Cipher – Part 1 | 117 | Nov. 2, 2022, 9 p.m. |
| Modified Caesar Cipher | 100 | Nov. 2, 2022, 8:28 p.m. |
| Zodiac Cipher | 100 | Nov. 1, 2022, 3:25 p.m. |
| News from Castle Mansfeld | 100 | Oct. 26, 2022, 9:46 p.m. |
| Image Noise | 100 | Oct. 26, 2022, 2:51 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Oct. 25, 2022, 9:07 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Oct. 25, 2022, 3:21 p.m. |
| Cracking SHA1-Hashed Passwords | 1,080 | Oct. 24, 2022, 7:26 p.m. |
| Molehunt (Part 2/3) | 100 | Oct. 24, 2022, 5:07 p.m. |
| Beaver Code | 100 | Oct. 24, 2022, 4:17 p.m. |
| Recycled One-Time Pad | 100 | Oct. 22, 2022, 5:41 p.m. |
| Molehunt (Part 1/3) | 100 | Oct. 22, 2022, 4:17 p.m. |
| Nils away on travel | 100 | Oct. 22, 2022, 3:35 p.m. |
| One-Time Pad with Flaws | 100 | Oct. 19, 2022, 8:49 p.m. |
| Grille Cipher | 100 | Oct. 18, 2022, 11:35 p.m. |
| Playfair with hints about the grid | 100 | Oct. 18, 2022, 8:20 p.m. |
| How do you become a big cryptographer? | 100 | Oct. 18, 2022, 8:01 p.m. |
| The Last Note | 100 | Oct. 18, 2022, 1:55 p.m. |
| A hidden word | 100 | Oct. 17, 2022, 6:47 p.m. |
| Playfair Encryption | 100 | Oct. 17, 2022, 5:23 p.m. |
| Number Sequence — Part 7 | 100 | Oct. 17, 2022, 4:01 p.m. |
| Number Sequence — Part 9 | 100 | Oct. 17, 2022, 3:39 p.m. |
| Monoalphabetic Substitution | 100 | Oct. 17, 2022, 3:06 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | Oct. 17, 2022, 1:30 p.m. |
| Letter to the Templars — Part 3 | 1,083 | Oct. 16, 2022, 11:58 p.m. |
| From Russia with Love | 100 | Oct. 16, 2022, 8:11 p.m. |
| A hidden word — Part 2 | 100 | Oct. 16, 2022, 7:54 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | Oct. 16, 2022, 7:41 p.m. |
| Snow White and the seven dwarfs | 100 | Oct. 16, 2022, 5:54 p.m. |
| Number Sequence — Part 8 | 100 | Oct. 16, 2022, 5:29 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Oct. 16, 2022, 3:38 p.m. |
| Number Sequence — Part 6 | 100 | Oct. 16, 2022, 2:59 p.m. |
| Autokey Cipher | 100 | Oct. 16, 2022, 1:15 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Oct. 16, 2022, 12:57 a.m. |
| Caesar Encryption | 100 | Oct. 16, 2022, 12:48 a.m. |
| Advent-Challenge — Part 1 | 100 | Oct. 15, 2022, 9:46 p.m. |
| Letter to the Templars — Part 2 | 100 | Oct. 15, 2022, 8:31 p.m. |
| Letter to the Templars — Part 1 | 100 | Oct. 15, 2022, 8:03 p.m. |
| Number Sequence — Part 4 | 100 | Oct. 15, 2022, 7:21 p.m. |
| Number Sequence — Part 3 | 100 | Oct. 15, 2022, 7:14 p.m. |
| Number Sequence — Part 2 | 100 | Oct. 15, 2022, 6:47 p.m. |
| Number Sequence | 100 | Oct. 15, 2022, 6:43 p.m. |
| Original Caesar Cipher | 100 | Oct. 15, 2022, 5:35 p.m. |
Gold0
Silver0
Bronze0
