| Weakened Granit — Part 1 | 100 | Jan. 30, 2024, 9:35 p.m. |
| Number Sequence — Part 10 | 100 | Jan. 18, 2023, 9:01 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 101 | Jan. 14, 2023, 5:04 p.m. |
| Cascading Encryption — Part 1/3 | 100 | Jan. 3, 2023, 6:29 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Nov. 23, 2022, 8:37 p.m. |
| Molehunt (Part 2/3) | 100 | Nov. 6, 2022, 5:59 p.m. |
| The Syllabary Cipher – Part 1 | 117 | Nov. 2, 2022, 8:03 p.m. |
| Enigma Combinatorics | 100 | Oct. 25, 2022, 8:31 p.m. |
| Alice's Birthday Party (Part 1) | 1,079 | June 7, 2022, 8:23 p.m. |
| RSA Factoring Challenge: RSA-220 | 0 | May 17, 2022, 8:24 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,080 | May 9, 2022, 8:57 p.m. |
| Polyhomophonic Substitution — Part 1 | 100 | April 26, 2022, 10:05 p.m. |
| Wheatstone Cryptograph — Part 1 | 100 | April 26, 2022, 9:28 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | April 12, 2022, 10:48 p.m. |
| Alberti Challenge — Part 1 | 106 | April 12, 2022, 8:51 p.m. |
| Pigpen with a twist — Part 1 | 100 | April 10, 2022, 11:22 a.m. |
| RSA Factoring Challenge: RSA-704 | 0 | Sept. 12, 2021, 9:49 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | Sept. 12, 2021, 9:32 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | Sept. 6, 2021, 9:10 p.m. |
| Number Sequence — Part 9 | 100 | Sept. 5, 2021, 12:03 a.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,081 | Sept. 4, 2021, 10:51 p.m. |
| Double Columnar Transposition | 100 | Sept. 1, 2021, 10:22 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Aug. 30, 2021, 8:53 p.m. |
| Enigma Messages | 100 | Aug. 29, 2021, 4:50 p.m. |
| Hill Cipher with Sudoku Key | 100 | June 6, 2021, 7:29 p.m. |
| Trifid Cipher | 100 | June 2, 2021, 10:20 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | May 31, 2021, 11:34 p.m. |
| Playfair with hints about the grid | 100 | May 24, 2021, 7:48 p.m. |
| Playfair Encryption | 100 | May 24, 2021, 7:26 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | May 24, 2021, 4:59 p.m. |
| Strange Message from Thessaloniki | 100 | May 23, 2021, 5:51 p.m. |
| One-Time Pad with Flaws | 100 | May 21, 2021, 9:02 p.m. |
| Classical Ciphers^3 | 100 | May 21, 2021, 7:47 p.m. |
| ADFGVX — Part 2 | 100 | May 16, 2021, 7:40 p.m. |
| ADFGVX — Part 1 | 100 | May 16, 2021, 5:23 p.m. |
| Image Noise | 100 | May 15, 2021, 1:45 p.m. |
| News from Castle Mansfeld | 100 | May 7, 2021, 11:23 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | May 6, 2021, 10:39 p.m. |
| M-138 — Part 2 | 1,094 | May 4, 2021, 10:29 p.m. |
| Autokey Cipher | 100 | May 4, 2021, 8:58 p.m. |
| The Last Note | 100 | May 4, 2021, 1:53 p.m. |
| M-138 — Part 1 | 100 | May 3, 2021, 9:37 p.m. |
| ¿No Hablas Español? No problemo! | 100 | May 2, 2021, 4:05 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | May 1, 2021, 11:22 p.m. |
| Molehunt (Part 1/3) | 100 | April 8, 2021, 3:21 p.m. |
| Find the right route — Part 2 | 101 | April 7, 2021, 9:51 p.m. |
| Modified Caesar Cipher | 100 | April 6, 2021, 9:01 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | April 6, 2021, 7:47 p.m. |
| Nils away on travel | 100 | April 5, 2021, 10:25 p.m. |
| A Secret Message from Castle Mansfeld | 100 | April 4, 2021, 10:16 p.m. |
| From Russia with Love | 100 | April 2, 2021, 12:40 a.m. |
| Grille Cipher | 100 | March 29, 2021, 5:40 p.m. |
| Zodiac Cipher | 100 | March 29, 2021, 2:32 p.m. |
| Factorization Cipher — Part 1 | 100 | March 29, 2021, 1:36 p.m. |
| Cracking SHA1-Hashed Passwords | 1,083 | March 29, 2021, 9:36 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | March 27, 2021, 8:22 p.m. |
| Find the right route — Part 1 | 101 | March 25, 2021, 5:48 p.m. |
| Advent-Challenge — Part 1 | 100 | March 23, 2021, 10:15 p.m. |
| Number Sequence — Part 6 | 100 | March 22, 2021, 10:10 p.m. |
| How do you become a big cryptographer? | 100 | March 22, 2021, 10 p.m. |
| A hidden word — Part 2 | 100 | March 22, 2021, 8:28 p.m. |
| Number Sequence — Part 8 | 100 | March 21, 2021, 7:33 p.m. |
| Snow White and the seven dwarfs | 100 | March 20, 2021, 10:31 p.m. |
| Number Sequence — Part 4 | 100 | March 20, 2021, 8:32 p.m. |
| Monoalphabetic Substitution | 100 | March 20, 2021, 7:14 p.m. |
| Number Sequence — Part 3 | 100 | March 20, 2021, 3:28 p.m. |
| A hidden word | 100 | March 19, 2021, 11:10 p.m. |
| Letter to the Templars — Part 3 | 1,087 | March 19, 2021, 11 p.m. |
| Letter to the Templars — Part 2 | 100 | March 19, 2021, 10:20 p.m. |
| Letter to the Templars — Part 1 | 100 | March 19, 2021, 9:44 p.m. |
| Beaver Code | 100 | March 18, 2021, 8:21 p.m. |
| Caesar Encryption | 100 | March 17, 2021, 9:13 p.m. |
| Number Sequence — Part 2 | 100 | March 17, 2021, 8:44 p.m. |
| Original Caesar Cipher | 100 | March 17, 2021, 8:28 p.m. |
| Number Sequence | 100 | March 17, 2021, 8:17 p.m. |