| Number Sequence — Part 9 | 103 | Dec. 21, 2017, 7:50 p.m. |
| Advent-Challenge — Part 1 | 107 | Dec. 21, 2017, 7:46 p.m. |
| M-138 — Part 2 | 1,155 | Jan. 11, 2016, 9 p.m. |
| A hidden word — Part 2 | 100 | Jan. 5, 2016, 9:36 p.m. |
| Concealed Messages — Vigenère's Night Sky | 1,109 | Jan. 3, 2016, 8:40 p.m. |
| News from Castle Mansfeld | 150 | Nov. 15, 2015, 8:23 a.m. |
| Weakened Granit — Part 1 | 114 | Sept. 30, 2015, 4:37 p.m. |
| Enigma Part 2 | 1,100 | Sept. 14, 2015, 7:26 p.m. |
| Number Sequence — Part 8 | 200 | Sept. 14, 2015, 6:51 p.m. |
| Enigma Part 1 | 1,102 | June 27, 2015, 10:42 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | June 16, 2015, 6:43 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | June 16, 2015, 6:39 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | June 16, 2015, 6:06 p.m. |
| Enigma Messages | 100 | June 13, 2015, 9:12 a.m. |
| Number Sequence — Part 7 | 102 | May 13, 2015, 9:53 p.m. |
| Number Sequence — Part 6 | 102 | May 13, 2015, 9:52 p.m. |
| Playfair with hints about the grid | 100 | Jan. 12, 2015, 8:01 p.m. |
| M-138 — Part 1 | 120 | Dec. 28, 2014, 9:12 p.m. |
| The Last Note | 117 | Sept. 28, 2014, 4:37 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | March 20, 2014, 8:58 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 133 | March 8, 2014, 3:11 p.m. |
| A really long number sequence | 1,122 | Feb. 20, 2014, 8:26 p.m. |
| Letter to the Templars — Part 3 | 1,144 | Feb. 19, 2014, 9:14 p.m. |
| Cascading Encryption — Part 1/3 | 100 | Feb. 15, 2014, 10:02 p.m. |
| Hill Cipher with Sudoku Key | 101 | Dec. 15, 2013, 9:19 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Dec. 14, 2013, 8:37 p.m. |
| Nils away on travel | 101 | Dec. 10, 2013, 8:37 p.m. |
| Zodiac Cipher | 100 | Dec. 9, 2013, 7:32 p.m. |
| Trifid Cipher | 125 | Nov. 1, 2013, 8:21 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 200 | Sept. 26, 2013, 9:25 p.m. |
| From Russia with Love | 108 | Sept. 15, 2013, 8:49 p.m. |
| Number Sequence — Part 5 | 100 | June 1, 2013, 8:32 p.m. |
| Snow White and the seven dwarfs | 120 | April 24, 2013, 9:30 p.m. |
| Reserve Hand Procedure — Part 1 | 200 | March 7, 2013, 6:58 p.m. |
| Kaskade-S/T — Part 1 | 100 | Feb. 13, 2013, 7:48 p.m. |
| Recycled One-Time Pad | 102 | Jan. 20, 2013, 8:38 p.m. |
| Double Columnar Transposition | 100 | Jan. 7, 2013, 9:22 p.m. |
| Strange Message from Thessaloniki | 104 | Jan. 6, 2013, 8:23 p.m. |
| A hidden word | 200 | Jan. 6, 2013, 8:22 p.m. |
| Molehunt (Part 1/3) | 100 | Dec. 21, 2012, 9:29 p.m. |
| Turing Bombe Enigma I | 100 | Dec. 19, 2012, 9:51 p.m. |
| How do you become a big cryptographer? | 101 | Nov. 25, 2012, 9:46 p.m. |
| Enigma Combinatorics | 100 | Nov. 25, 2012, 9:24 p.m. |
| Molehunt (Part 2/3) | 100 | Oct. 31, 2012, 9:32 p.m. |
| Classical Ciphers^3 | 100 | Oct. 31, 2012, 8:48 p.m. |
| Number Sequence — Part 3 | 100 | Oct. 29, 2012, 9:26 p.m. |
| ADFGVX — Part 1 | 100 | Oct. 29, 2012, 9:23 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Sept. 23, 2012, 8:30 p.m. |
| Monoalphabetic Substitution | 100 | Sept. 6, 2012, 9:19 p.m. |
| ADFGVX — Part 2 | 100 | Sept. 6, 2012, 9:15 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Sept. 3, 2012, 8:34 p.m. |
| ECDH-Key Exchange for Beginners | 101 | Sept. 3, 2012, 7:42 p.m. |
| Beaver Code | 200 | Aug. 13, 2012, 9:55 p.m. |
| The Book Code: A Challenge for Bookworms | 101 | Aug. 4, 2012, 7:47 p.m. |
| Letter to the Templars — Part 2 | 200 | July 31, 2012, 8:05 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | July 29, 2012, 8:09 p.m. |
| Letter to the Templars — Part 1 | 117 | July 22, 2012, 7:26 p.m. |
| Pigpen with a twist — Part 1 | 100 | July 22, 2012, 6:43 p.m. |
| Caesar Encryption | 100 | July 22, 2012, 6:35 p.m. |
| One-Time Pad with Flaws | 100 | July 15, 2012, 7:35 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | July 15, 2012, 7:34 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | July 15, 2012, 7:20 p.m. |
| Modified Caesar Cipher | 100 | July 8, 2012, 2:30 p.m. |
| Factorization Cipher — Part 1 | 100 | June 10, 2012, 7:47 p.m. |
| Grille Cipher | 100 | June 8, 2012, 9:21 p.m. |
| Number Sequence — Part 4 | 102 | June 8, 2012, 7:13 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | June 7, 2012, 8:17 p.m. |
| Number Sequence — Part 2 | 100 | June 7, 2012, 8:16 p.m. |
| Original Caesar Cipher | 100 | June 5, 2012, 8:44 p.m. |
| Number Sequence | 100 | June 4, 2012, 9:30 p.m. |