| Advent Challenge — Part 3 | 1,098 | May 31, 2023, 1:54 a.m. |
| Advent-Challenge — Part 2 | 1,098 | May 25, 2023, 11:48 p.m. |
| The Hutton Cipher – Part 1 | 1,660 | May 6, 2023, 3:30 a.m. |
| A really long number sequence | 1,079 | May 1, 2023, 3:11 p.m. |
| Number Sequence — Part 10 | 100 | April 28, 2023, 11:21 p.m. |
| A Secret Message from Castle Mansfeld | 100 | April 27, 2023, 11:13 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | April 25, 2023, 10:51 p.m. |
| RSA: Two different keys — same ciphertext | 1,080 | March 23, 2023, 11:34 p.m. |
| Number Sequence — Part 9 | 100 | Feb. 4, 2023, 10:30 a.m. |
| M-138 — Part 2 | 1,088 | Jan. 30, 2023, 12:46 p.m. |
| Factorization Cipher — Part 2 | 1,080 | Jan. 18, 2023, 11:34 a.m. |
| Lightweight Introduction to Lattices — Part 1 | 100 | Jan. 13, 2023, 8:06 a.m. |
| Cracking SHA1-Hashed Passwords | 1,079 | Jan. 13, 2023, 7:31 a.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,078 | Jan. 12, 2023, 3:57 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,080 | Jan. 11, 2023, 10:55 p.m. |
| Alice's Birthday Party (Part 2) | 1,078 | Jan. 7, 2023, 3:07 p.m. |
| Alice's Birthday Party (Part 1) | 1,078 | Jan. 6, 2023, 10:40 p.m. |
| Letter to the Templars — Part 3 | 1,082 | Jan. 2, 2023, 12:10 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | Dec. 28, 2022, 11:10 p.m. |
| Lightweight Introduction to Lattices — Part 3 | 1,122 | Dec. 23, 2022, 8:24 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 101 | Dec. 20, 2022, 2:33 p.m. |
| Double Columnar Transposition | 100 | Dec. 19, 2022, 11:08 p.m. |
| Find the right route — Part 1 | 100 | Dec. 12, 2022, 10:53 p.m. |
| The Syllabary Cipher – Part 3 | 1,357 | Nov. 21, 2022, 9:21 p.m. |
| The Syllabary Cipher – Part 2 | 1,456 | Nov. 8, 2022, 8:59 p.m. |
| The Syllabary Cipher – Part 1 | 117 | Nov. 2, 2022, 7 p.m. |
| Playfair with hints about the grid | 100 | Nov. 2, 2022, 3:34 p.m. |
| Molehunt (Part 2/3) | 100 | Nov. 1, 2022, 7:32 p.m. |
| ADFGVX — Part 2 | 100 | Oct. 29, 2022, 6:58 p.m. |
| ADFGVX — Part 1 | 100 | Oct. 29, 2022, 2:52 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | Oct. 19, 2022, 8:31 p.m. |
| Playfair Encryption | 100 | Oct. 19, 2022, 2:41 p.m. |
| Trifid Cipher | 100 | Sept. 28, 2022, 1:35 a.m. |
| Molehunt (Part 1/3) | 100 | Sept. 21, 2022, 10:11 p.m. |
| Autokey Cipher | 100 | Sept. 21, 2022, 8:03 p.m. |
| Nils away on travel | 100 | Sept. 21, 2022, 11:05 a.m. |
| ¿No Hablas Español? No problemo! | 100 | Sept. 21, 2022, 12:48 a.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | Sept. 21, 2022, 12:17 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Sept. 20, 2022, 11:55 p.m. |
| Classical Ciphers^3 | 100 | Sept. 17, 2022, 9:14 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Sept. 7, 2022, 12:14 a.m. |
| M-138 — Part 1 | 100 | Aug. 29, 2022, 10:04 p.m. |
| How do you become a big cryptographer? | 100 | Aug. 26, 2022, 6:54 p.m. |
| Modified Caesar Cipher | 100 | Aug. 25, 2022, 10:11 a.m. |
| From Russia with Love | 100 | Aug. 14, 2022, 7:05 p.m. |
| Wheatstone Cryptograph — Part 1 | 100 | Aug. 11, 2022, 12:45 a.m. |
| Snow White and the seven dwarfs | 100 | Aug. 3, 2022, 10:38 p.m. |
| One-Time Pad with Flaws | 100 | Aug. 3, 2022, 8:38 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Aug. 1, 2022, 2:04 p.m. |
| Number Sequence — Part 6 | 100 | July 31, 2022, 9:57 p.m. |
| Number Sequence — Part 8 | 100 | July 31, 2022, 9:14 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | July 31, 2022, 5:32 p.m. |
| Advent-Challenge — Part 1 | 100 | July 31, 2022, 9:28 a.m. |
| Grille Cipher | 100 | July 30, 2022, 7:39 p.m. |
| Factorization Cipher — Part 1 | 100 | July 27, 2022, 10:18 a.m. |
| Monoalphabetic Substitution | 100 | July 26, 2022, 2:14 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | July 22, 2022, 10:40 p.m. |
| A hidden word | 100 | July 22, 2022, 3:02 p.m. |
| Letter to the Templars — Part 2 | 100 | July 21, 2022, 9:58 p.m. |
| Number Sequence — Part 4 | 100 | July 21, 2022, 9:02 p.m. |
| Number Sequence — Part 3 | 100 | July 21, 2022, 8:39 p.m. |
| Letter to the Templars — Part 1 | 100 | July 21, 2022, 5:25 p.m. |
| Beaver Code | 100 | July 21, 2022, 4:35 p.m. |
| Caesar Encryption | 100 | July 21, 2022, 2:31 p.m. |
| Number Sequence — Part 2 | 100 | July 21, 2022, 2:08 p.m. |
| Original Caesar Cipher | 100 | July 21, 2022, 1:51 p.m. |
| Number Sequence | 100 | July 21, 2022, 1:29 p.m. |
| Alberti Challenge — Part 1 | 101 | July 18, 2022, 5:47 p.m. |
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