| Advent-Challenge — Part 1 | 150 | Dec. 10, 2017, 7:27 a.m. |
| Zodiac Cipher | 100 | Sept. 23, 2017, 11:46 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | July 8, 2017, 12:03 p.m. |
| A hidden word — Part 2 | 100 | June 30, 2017, 7:51 a.m. |
| Enigma Combinatorics | 100 | June 29, 2017, 8:20 a.m. |
| ADFGVX — Part 2 | 100 | June 29, 2017, 5:32 a.m. |
| ADFGVX — Part 1 | 100 | June 24, 2017, 5:16 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | June 21, 2017, 1:06 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | May 29, 2017, 8:50 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | May 29, 2017, 8:02 a.m. |
| Number Sequence — Part 8 | 100 | May 27, 2017, 10:55 a.m. |
| Image Noise | 100 | July 14, 2016, 4:13 a.m. |
| Trifid Cipher | 100 | March 11, 2015, 3:20 a.m. |
| One-Time Pad with Flaws | 100 | Feb. 13, 2015, 10:15 a.m. |
| Multilingual Monoalphabetic Substitution | 100 | Dec. 31, 2014, 11:22 a.m. |
| M-138 — Part 1 | 120 | Dec. 28, 2014, 2:49 p.m. |
| Playfair with hints about the grid | 100 | Dec. 28, 2014, 3:12 a.m. |
| Pigpen with a twist — Part 1 | 100 | Dec. 22, 2014, 8:56 a.m. |
| Letter to the Templars — Part 2 | 100 | Dec. 21, 2014, 6:31 a.m. |
| Factorization Cipher — Part 1 | 100 | Dec. 19, 2014, 4:01 a.m. |
| Number Sequence — Part 3 | 100 | Dec. 18, 2014, 10:51 p.m. |
| Modified Caesar Cipher | 100 | Dec. 18, 2014, 9:33 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Dec. 15, 2014, 2:42 a.m. |
| Grille Cipher | 100 | Dec. 13, 2014, 4:03 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Dec. 12, 2014, 10:48 p.m. |
| Monoalphabetic Substitution | 100 | Dec. 12, 2014, 10:03 p.m. |
| Number Sequence — Part 2 | 100 | Dec. 6, 2014, 1:35 p.m. |
| Classical Ciphers^3 | 100 | Dec. 6, 2014, 11:06 a.m. |
| How do you become a big cryptographer? | 100 | Nov. 29, 2014, 12:30 p.m. |
| Letter to the Templars — Part 1 | 100 | Nov. 29, 2014, 11:39 a.m. |
| Beaver Code | 100 | Nov. 27, 2014, 8:15 a.m. |
| Playfair Encryption | 100 | Nov. 16, 2014, 12:32 p.m. |
| Molehunt (Part 2/3) | 100 | Nov. 16, 2014, 10:27 a.m. |
| Caesar Encryption | 100 | Nov. 16, 2014, 10:07 a.m. |
| Molehunt (Part 1/3) | 100 | Nov. 16, 2014, 9:15 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Nov. 13, 2014, 5:47 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Nov. 13, 2014, 7:23 a.m. |
| A hidden word | 100 | Nov. 8, 2014, 7:01 a.m. |
| Original Caesar Cipher | 100 | Nov. 8, 2014, 6:10 a.m. |
| Heartbleed — Part 1 | 101 | Nov. 4, 2014, 2:20 p.m. |
| Snow White and the seven dwarfs | 100 | Nov. 4, 2014, 10:49 a.m. |
| Cascading Encryption — Part 1/3 | 100 | Nov. 3, 2014, 4:27 p.m. |
| Hill Cipher with Sudoku Key | 100 | Oct. 31, 2014, 12:56 a.m. |
| The Last Note | 105 | Oct. 11, 2014, 11:46 a.m. |
| The Book Code: A Challenge for Bookworms | 100 | Oct. 11, 2014, 10:08 a.m. |
| Nils away on travel | 100 | Sept. 22, 2014, 5:33 p.m. |
| From Russia with Love | 100 | Sept. 21, 2014, 5:58 p.m. |
| Number Sequence | 100 | Sept. 5, 2014, 7:09 a.m. |