| Letter to the Templars — Part 3 | 1,094 | Feb. 20, 2019, 10:05 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,613 | Feb. 20, 2019, 9:29 p.m. |
| Modular Sequences | 101 | Feb. 18, 2019, 11:51 p.m. |
| Classical Ciphers^3 | 100 | Feb. 18, 2019, 9:57 p.m. |
| Monoalphabetic Substitution | 100 | Feb. 18, 2019, 7:45 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Feb. 18, 2019, 7:10 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Feb. 18, 2019, 4:50 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Feb. 18, 2019, 4:46 p.m. |
| Number Sequence — Part 2 | 100 | Feb. 18, 2019, 3:31 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Feb. 18, 2019, 3:26 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | Feb. 18, 2019, 2:44 p.m. |
| How do you become a big cryptographer? | 100 | Feb. 18, 2019, 12:31 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | Feb. 17, 2019, 10:45 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Feb. 17, 2019, 9:53 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Feb. 17, 2019, 8:21 p.m. |
| Image Noise | 100 | Feb. 16, 2019, 6:03 p.m. |
| Number Sequence — Part 10 | 100 | Feb. 16, 2019, 5:47 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 103 | Feb. 16, 2019, 4:59 p.m. |
| Autokey Cipher | 101 | Jan. 2, 2019, 11:49 p.m. |
| Nils away on travel | 100 | Nov. 24, 2018, 11:22 p.m. |
| From Russia with Love | 100 | Nov. 24, 2018, 11:11 p.m. |
| Number Sequence — Part 8 | 100 | Nov. 24, 2018, 9:22 p.m. |
| Advent-Challenge — Part 1 | 100 | Nov. 24, 2018, 8:41 p.m. |
| Grille Cipher | 100 | Nov. 15, 2012, 12:01 a.m. |
| Factorization Cipher — Part 1 | 100 | Nov. 14, 2012, 11:15 p.m. |
| Number Sequence — Part 3 | 100 | Nov. 14, 2012, 10:44 p.m. |
| Number Sequence — Part 4 | 100 | Nov. 14, 2012, 10:41 p.m. |
| An 'unhearable' message | 101 | Nov. 14, 2012, 10:16 p.m. |
| Beaver Code | 101 | Nov. 14, 2012, 8:20 p.m. |
| Letter to the Templars — Part 2 | 101 | Nov. 14, 2012, 7:58 p.m. |
| Letter to the Templars — Part 1 | 101 | Nov. 14, 2012, 7:51 p.m. |
| Number Sequence | 100 | July 5, 2011, 4:23 a.m. |
| Caesar Encryption | 100 | July 5, 2011, 4:21 a.m. |
| Original Caesar Cipher | 100 | July 5, 2011, 4:09 a.m. |