| Alice's Birthday Party (Part 1) | 1,078 | April 4, 2023, 12:57 p.m. |
| M-138 — Part 3 | 1,087 | April 3, 2023, 1:24 p.m. |
| Enigma Messages | 100 | March 28, 2023, 2:16 p.m. |
| Playfair Encryption | 100 | March 22, 2023, 4:09 p.m. |
| ¿No Hablas Español? No problemo! | 100 | March 22, 2023, 12:13 p.m. |
| Double Columnar Transposition | 100 | March 21, 2023, 3:34 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | March 21, 2023, 11:02 a.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | March 21, 2023, 9:53 a.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | March 21, 2023, 8:03 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | March 20, 2023, 9:59 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | March 17, 2023, 6:55 p.m. |
| Molehunt (Part 1/3) | 100 | March 16, 2023, 8:15 a.m. |
| ADFGVX — Part 1 | 100 | March 15, 2023, 11:28 a.m. |
| The Syllabary Cipher – Part 1 | 101 | March 6, 2023, 11:42 a.m. |
| From Russia with Love | 100 | March 6, 2023, 11:14 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Feb. 27, 2023, 9 a.m. |
| Nils away on travel | 100 | Feb. 22, 2023, 9:15 a.m. |
| Playfair with hints about the grid | 100 | Feb. 21, 2023, 10:32 a.m. |
| Lightweight Introduction to Lattices — Part 1 | 100 | May 5, 2021, 3:32 p.m. |
| Wheatstone Cryptograph — Part 1 | 108 | May 4, 2021, 11:06 a.m. |
| M-138 — Part 2 | 1,096 | Oct. 19, 2020, 4:18 p.m. |
| M-138 — Part 1 | 100 | Oct. 14, 2020, 1:59 p.m. |
| Autokey Cipher | 100 | Dec. 12, 2019, 5:26 a.m. |
| Reserve Hand Procedure — Part 1 | 100 | Dec. 10, 2019, 2 p.m. |
| Number Sequence — Part 8 | 100 | Nov. 23, 2019, 9:39 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Nov. 23, 2019, 8:34 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Nov. 23, 2019, 7:47 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Nov. 21, 2019, 11:06 a.m. |
| Number Sequence — Part 4 | 100 | Nov. 15, 2019, 8:02 a.m. |
| Number Sequence — Part 3 | 100 | Nov. 14, 2019, 9 a.m. |
| Factorization Cipher — Part 1 | 100 | Oct. 28, 2019, 3:14 p.m. |
| Advent-Challenge — Part 1 | 100 | Oct. 22, 2019, 11:27 a.m. |
| Letter to the Templars — Part 3 | 1,091 | Oct. 21, 2019, 9:45 p.m. |
| Grille Cipher | 100 | Oct. 18, 2019, 6:18 a.m. |
| Beaver Code | 100 | Oct. 17, 2019, 6:53 a.m. |
| Caesar Encryption | 100 | Oct. 16, 2019, 11:06 a.m. |
| Cracking SHA1-Hashed Passwords | 1,086 | Oct. 16, 2019, 9:36 a.m. |
| A hidden word | 100 | Oct. 15, 2019, 4:37 p.m. |
| Letter to the Templars — Part 2 | 100 | Oct. 15, 2019, 4:16 p.m. |
| Letter to the Templars — Part 1 | 100 | Oct. 15, 2019, 2:08 p.m. |
| Number Sequence — Part 2 | 100 | Oct. 13, 2019, 8:31 a.m. |
| Original Caesar Cipher | 100 | Oct. 11, 2019, 8:36 a.m. |
| Number Sequence | 100 | Oct. 11, 2019, 7:57 a.m. |