| Autokey Cipher | 100 | Feb. 29, 2020, 2:10 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | Feb. 14, 2020, 11:06 a.m. |
| Advent-Challenge — Part 1 | 102 | Jan. 26, 2018, 12:41 p.m. |
| Number Sequence — Part 8 | 100 | Nov. 29, 2016, 1:22 p.m. |
| News from Castle Mansfeld | 101 | Jan. 19, 2016, 4:05 p.m. |
| A hidden word — Part 2 | 108 | April 28, 2015, 9:28 a.m. |
| Double Column Transposition — Part 4 | 1,170 | Feb. 22, 2015, 2:28 p.m. |
| Enigma Messages | 100 | Feb. 16, 2015, 1:41 p.m. |
| Double Column Transposition — Part 1 | 1,165 | Feb. 4, 2015, 6:13 p.m. |
| Double Column Transposition — Part 3 | 1,170 | Feb. 3, 2015, 5:13 p.m. |
| Double Column Transposition — Part 2 | 1,170 | Feb. 3, 2015, 8:37 a.m. |
| Double Columnar Transposition | 100 | Feb. 2, 2015, 4:32 p.m. |
| Strange Message from Thessaloniki | 100 | Jan. 13, 2015, 12:25 p.m. |
| M-138 — Part 2 | 1,398 | Jan. 10, 2015, 11:21 a.m. |
| M-138 — Part 1 | 106 | Jan. 9, 2015, 10:31 a.m. |
| The Last Note | 101 | Jan. 9, 2015, 9:26 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 101 | June 30, 2014, 11:47 a.m. |
| Enigma Messages with Repeated Letters — Part 4 | 101 | June 30, 2014, 11:39 a.m. |
| Enigma Messages with Repeated Letters — Part 3 | 101 | June 30, 2014, 11:22 a.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Feb. 17, 2014, 8:19 a.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,126 | Feb. 11, 2014, 9:56 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Jan. 31, 2014, 10:46 a.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,127 | Jan. 22, 2014, 3:13 p.m. |
| Kaskade-S/T — Part 3 | 1,117 | Jan. 8, 2014, 3:31 p.m. |
| Kaskade-S/T — Part 2 | 1,117 | Dec. 23, 2013, 2:30 p.m. |
| Cascading Encryption — Part 1/3 | 100 | Dec. 14, 2013, 11:09 a.m. |
| Turing Bombe Enigma I | 100 | Dec. 13, 2013, 4:41 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 102 | Dec. 9, 2013, 5:29 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 101 | Dec. 3, 2013, 10:13 a.m. |
| Trifid Cipher | 103 | Nov. 26, 2013, 2:56 p.m. |
| Nils away on travel | 101 | Nov. 24, 2013, 9:14 p.m. |
| From Russia with Love | 101 | Nov. 21, 2013, 6:53 p.m. |
| Snow White and the seven dwarfs | 125 | April 23, 2013, 4:22 p.m. |
| Number Sequence — Part 3 | 100 | April 12, 2013, 9:01 a.m. |
| Reserve Hand Procedure — Part 1 | 104 | March 29, 2013, 1:26 p.m. |
| BCR code (Book-Caesar-RSA) | 1,188 | March 28, 2013, 9:04 a.m. |
| Letter to the Templars — Part 3 | 1,197 | March 26, 2013, 8:24 a.m. |
| Multilingual Monoalphabetic Substitution | 102 | March 25, 2013, 7:37 p.m. |
| Playfair with hints about the grid | 101 | March 23, 2013, 4:30 p.m. |
| A hidden word | 101 | March 22, 2013, 8:31 a.m. |
| Beaver Code | 125 | Aug. 17, 2012, 10:45 a.m. |
| A really long number sequence | 1,160 | Aug. 17, 2012, 7:35 a.m. |
| Number Sequence — Part 4 | 101 | Aug. 5, 2012, 11:24 a.m. |
| Letter to the Templars — Part 2 | 125 | Aug. 3, 2012, 8:51 a.m. |
| A Secret Message from Castle Mansfeld | 100 | Aug. 2, 2012, 2:25 p.m. |
| Pigpen with a twist — Part 2 | 1,161 | Aug. 1, 2012, 12:29 p.m. |
| Pigpen with a twist — Part 3 | 1,162 | July 29, 2012, 3:06 p.m. |
| Letter to the Templars — Part 1 | 108 | July 28, 2012, 8:56 a.m. |
| Playfair Encryption | 100 | July 12, 2012, 2:26 p.m. |
| Ku Klux Klan | 1,000 | June 22, 2012, 5:38 p.m. |
| Keyshanc — Part 2 | 1,373 | June 12, 2012, 2:30 p.m. |
| Keyshanc — Part 1 | 1,378 | June 11, 2012, 3:25 p.m. |
| An 'unhearable' message | 117 | June 11, 2012, 10:18 a.m. |
| An Invisible Message | 100 | June 9, 2012, 3:28 p.m. |
| Factorization Cipher — Part 2 | 1,190 | June 9, 2012, 7:05 a.m. |
| How do you become a big cryptographer? | 113 | June 4, 2012, 5:51 p.m. |
| Enigma Part 1 | 1,137 | June 4, 2012, 11:19 a.m. |
| Enigma Part 2 | 1,137 | June 1, 2012, 10:07 a.m. |
| Hybrid Encryption I | 1,138 | May 31, 2012, 2:43 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,137 | May 28, 2012, 3:11 p.m. |
| RSA: Two different keys — same ciphertext | 1,169 | May 28, 2012, 10:40 a.m. |
| ECDH-Key Exchange for Beginners | 101 | May 27, 2012, 12:14 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,166 | May 23, 2012, 1:37 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,137 | May 23, 2012, 8:47 a.m. |
| ADFGVX — Part 2 | 100 | May 22, 2012, 6:36 p.m. |
| ADFGVX — Part 1 | 100 | May 22, 2012, 3:37 p.m. |
| Cracking SHA1-Hashed Passwords | 1,152 | May 21, 2012, 10:45 a.m. |
| Alice's Birthday Party (Part 1) | 1,138 | May 19, 2012, 11:59 a.m. |
| Alice's Birthday Party (Part 2) | 1,138 | May 19, 2012, 7 a.m. |
| Classical Ciphers^3 | 100 | April 26, 2012, 11:29 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | April 25, 2012, 3:31 p.m. |
| ¿No Hablas Español? No problemo! | 114 | April 25, 2012, 2:55 p.m. |
| Pigpen with a twist — Part 1 | 100 | April 25, 2012, 1:55 p.m. |
| Kaskade-S/T — Part 1 | 100 | April 24, 2012, 1:41 p.m. |
| Molehunt (Part 3/3) | 1,140 | April 17, 2012, 12:02 p.m. |
| Molehunt (Part 1/3) | 100 | April 16, 2012, 3:27 p.m. |
| Molehunt (Part 2/3) | 100 | April 16, 2012, 2:47 p.m. |
| Modified Caesar Cipher | 100 | April 8, 2012, 2:49 p.m. |
| Grille Cipher | 101 | April 6, 2012, 11:57 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | April 6, 2012, 10:04 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | April 5, 2012, 11:19 a.m. |
| One-Time Pad with Flaws | 100 | April 5, 2012, 10:36 a.m. |
| Number Sequence | 100 | April 4, 2012, 11:19 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | April 4, 2012, 10:24 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | April 3, 2012, 3:23 p.m. |
| Caesar Encryption | 100 | April 3, 2012, 2:58 p.m. |
| Zodiac Cipher | 100 | April 3, 2012, 9:02 a.m. |
| Monoalphabetic Substitution | 100 | April 2, 2012, 1:44 p.m. |
| Original Caesar Cipher | 100 | April 1, 2012, 2:33 p.m. |
| Number Sequence — Part 2 | 100 | April 1, 2012, 2:20 p.m. |
| Factorization Cipher — Part 1 | 101 | April 1, 2012, 1:12 p.m. |
| The Book Code: A Challenge for Bookworms | 110 | March 30, 2012, 4:32 p.m. |