| Advent-Challenge — Part 1 | 133 | Dec. 11, 2017, 9:51 a.m. |
| Number Sequence — Part 9 | 125 | Nov. 20, 2017, 5:27 p.m. |
| Recycled One-Time Pad | 100 | Sept. 2, 2016, 1:08 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Aug. 24, 2016, 2:07 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,102 | Aug. 4, 2016, 7:29 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,102 | Aug. 3, 2016, 1:32 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Aug. 2, 2016, 3:41 p.m. |
| Playfair Encryption | 100 | July 28, 2016, 3:56 p.m. |
| Double Column Transposition — Part 3 | 1,125 | July 19, 2016, 10:40 a.m. |
| New Year's Greetings — Part 5 | 1,414 | April 5, 2016, 1:31 p.m. |
| New Year's Greetings — Part 4 | 120 | March 25, 2016, 4:21 p.m. |
| New Year's Greetings — Part 3 | 125 | March 25, 2016, 9:46 a.m. |
| New Year's Greetings — Part 2 | 133 | March 23, 2016, 11:44 a.m. |
| New Year's Greetings — Part 1 | 133 | March 23, 2016, 10:48 a.m. |
| Image Noise | 150 | Nov. 22, 2015, 6:36 p.m. |
| News from Castle Mansfeld | 125 | Nov. 16, 2015, 7:25 p.m. |
| Weakened Granit — Part 1 | 125 | Sept. 27, 2015, 8:29 p.m. |
| M-138 — Part 2 | 1,172 | Sept. 17, 2015, 6:12 p.m. |
| Number Sequence — Part 8 | 200 | Sept. 14, 2015, 12:09 p.m. |
| Enigma Messages | 100 | July 13, 2015, 1:58 p.m. |
| Zodiac Cipher | 100 | July 6, 2015, 6:30 p.m. |
| M-138 — Part 1 | 101 | June 30, 2015, 9:28 a.m. |
| Playfair with hints about the grid | 100 | May 12, 2015, 4:01 p.m. |
| Number Sequence — Part 7 | 102 | May 7, 2015, 11:43 a.m. |
| A hidden word — Part 2 | 113 | April 24, 2015, 3:39 p.m. |
| Number Sequence — Part 6 | 200 | March 23, 2015, 2:58 p.m. |
| Turing Bombe Enigma I | 100 | March 18, 2015, 8:54 p.m. |
| Enigma Combinatorics | 100 | March 1, 2015, 7:57 p.m. |
| Enigma Part 1 | 1,104 | Feb. 23, 2015, 7:06 p.m. |
| An 'unhearable' message | 100 | Dec. 22, 2014, 3:38 p.m. |
| An Invisible Message | 100 | Nov. 19, 2014, 10:45 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Oct. 23, 2014, 4:23 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | Oct. 15, 2014, 7:36 a.m. |
| RSA Factoring Challenge: RSA-704 | 0 | Oct. 14, 2014, 7:18 p.m. |
| Double Column Transposition — Part 4 | 1,205 | Oct. 14, 2014, 6:57 p.m. |
| Ku Klux Klan | 1,000 | Sept. 29, 2014, 7:10 p.m. |
| The Last Note | 200 | Sept. 23, 2014, 11:07 a.m. |
| Double Columnar Transposition | 100 | Sept. 18, 2014, 12:07 p.m. |
| Double Column Transposition — Part 2 | 1,210 | Sept. 15, 2014, 4:25 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Aug. 4, 2014, 2:34 p.m. |
| Enigma Part 2 | 1,108 | Aug. 4, 2014, 10:09 a.m. |
| Kaskade-S/T — Part 1 | 100 | Aug. 4, 2014, 9:40 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | July 28, 2014, 11:12 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 101 | July 28, 2014, 10:54 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 101 | July 28, 2014, 10:41 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 101 | July 28, 2014, 9:59 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,121 | July 28, 2014, 8:23 p.m. |
| Cascading Encryption — Part 1/3 | 100 | July 14, 2014, 8:07 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | June 30, 2014, 8:16 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | April 4, 2014, 3:03 p.m. |
| Factorization Cipher — Part 1 | 100 | March 31, 2014, 11:48 a.m. |
| Trifid Cipher | 125 | Oct. 31, 2013, 9:24 p.m. |
| One-Time Pad with Flaws | 100 | Oct. 10, 2013, 3:48 p.m. |
| Molehunt (Part 2/3) | 100 | Oct. 1, 2013, 8:24 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 150 | Sept. 27, 2013, 4:25 p.m. |
| Molehunt (Part 1/3) | 100 | Sept. 27, 2013, 4:04 p.m. |
| Pigpen with a twist — Part 1 | 100 | Sept. 19, 2013, 6:48 p.m. |
| From Russia with Love | 108 | Sept. 16, 2013, 6:12 p.m. |
| Nils away on travel | 200 | Aug. 9, 2013, 12:16 a.m. |
| Classical Ciphers^3 | 100 | July 15, 2013, 3:25 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | July 5, 2013, 2:03 p.m. |
| ADFGVX — Part 1 | 100 | July 2, 2013, 4:33 p.m. |
| Reserve Hand Procedure — Part 1 | 101 | June 28, 2013, 2:55 p.m. |
| ADFGVX — Part 2 | 100 | June 26, 2013, 3:57 p.m. |
| Cracking SHA1-Hashed Passwords | 1,126 | June 19, 2013, 3:58 p.m. |
| Modified Caesar Cipher | 100 | June 19, 2013, 9:06 a.m. |
| Letter to the Templars — Part 3 | 1,176 | June 14, 2013, 4:20 p.m. |
| Number Sequence — Part 5 | 100 | May 7, 2013, 10:29 a.m. |
| How do you become a big cryptographer? | 100 | April 30, 2013, 9:49 a.m. |
| The Book Code: A Challenge for Bookworms | 100 | April 26, 2013, 7:15 p.m. |
| A Secret Message from Castle Mansfeld | 100 | April 24, 2013, 4:25 p.m. |
| Number Sequence — Part 4 | 100 | April 24, 2013, 12:42 p.m. |
| Monoalphabetic Substitution | 100 | April 24, 2013, 11:21 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | April 23, 2013, 9:56 p.m. |
| Grille Cipher | 100 | April 23, 2013, 1:11 p.m. |
| Number Sequence — Part 2 | 100 | April 22, 2013, 10:48 a.m. |
| Snow White and the seven dwarfs | 150 | April 22, 2013, 9:36 a.m. |
| Strange Message from Thessaloniki | 101 | April 21, 2013, 1:54 a.m. |
| Number Sequence | 100 | April 17, 2013, 4:41 p.m. |
| Number Sequence — Part 3 | 100 | April 17, 2013, 4:09 p.m. |
| Letter to the Templars — Part 1 | 100 | April 17, 2013, 4:02 p.m. |
| Letter to the Templars — Part 2 | 100 | April 10, 2013, 5:38 p.m. |
| Beaver Code | 100 | April 9, 2013, 11:31 p.m. |
| A hidden word | 101 | April 9, 2013, 12:52 p.m. |
| Caesar Encryption | 100 | April 9, 2013, 12:44 p.m. |
| Original Caesar Cipher | 100 | April 8, 2013, 7:16 p.m. |