| The Syllabary Cipher – Part 1 | 100 | July 21, 2023, 8:23 p.m. |
| RSA Factoring Challenge: RSA-232 | 0 | May 3, 2022, 6:14 p.m. |
| RSA Factoring Challenge: RSA-250 | 0 | May 3, 2022, 6:13 p.m. |
| RSA Factoring Challenge: RSA-240 | 0 | May 3, 2022, 6:12 p.m. |
| Modular Sequences | 100 | May 3, 2022, 6:08 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,080 | May 3, 2022, 5:05 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | April 27, 2022, 12:32 a.m. |
| Classical Ciphers^3 | 100 | April 27, 2022, 12:30 a.m. |
| A hidden word — Part 2 | 100 | April 25, 2022, 12:48 a.m. |
| Autokey Cipher | 100 | April 24, 2022, 8:13 p.m. |
| Wheatstone Cryptograph — Part 1 | 100 | April 24, 2022, 6:56 p.m. |
| Alberti Challenge — Part 1 | 103 | April 24, 2022, 5:47 p.m. |
| Number Sequence — Part 7 | 100 | May 18, 2019, 11:35 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | March 24, 2019, 7:41 p.m. |
| M-138 — Part 4 | 1,105 | March 24, 2019, 7 p.m. |
| M-138 — Part 2 | 1,105 | March 23, 2019, 9:08 p.m. |
| RSA Factoring Challenge: RSA-220 | 0 | June 12, 2018, 9:39 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | June 12, 2018, 9:37 p.m. |
| RSA Factoring Challenge: RSA-704 | 0 | June 12, 2018, 9:36 p.m. |
| M-138 — Part 1 | 100 | June 9, 2018, 8:02 p.m. |
| Snow White and the seven dwarfs | 100 | June 7, 2018, 9:13 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | June 6, 2018, 10:42 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | June 2, 2018, 9:49 p.m. |
| Modified Caesar Cipher | 100 | June 2, 2018, 6:21 p.m. |
| The Last Note | 100 | June 1, 2018, 1:27 a.m. |
| One-Time Pad with Flaws | 100 | May 31, 2018, 3:30 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | May 28, 2018, 6:14 p.m. |
| Monoalphabetic Substitution | 100 | May 28, 2018, 5:37 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | May 26, 2018, 11:27 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | May 26, 2018, 11:16 p.m. |
| Cracking SHA1-Hashed Passwords | 1,091 | May 26, 2018, 10:53 p.m. |
| Number Sequence — Part 9 | 101 | April 14, 2018, 10:15 p.m. |
| Pigpen with a twist — Part 3 | 1,093 | April 14, 2018, 9:51 p.m. |
| Trifid Cipher | 100 | April 13, 2018, 11:40 p.m. |
| Image Noise | 100 | April 12, 2018, 1:15 a.m. |
| ¿No Hablas Español? No problemo! | 100 | April 12, 2018, 1:03 a.m. |
| A really long number sequence | 1,093 | April 11, 2018, 11:17 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | April 11, 2018, 1:57 a.m. |
| Pigpen with a twist — Part 1 | 100 | April 11, 2018, 1 a.m. |
| From Russia with Love | 100 | April 10, 2018, 11:41 p.m. |
| Advent-Challenge — Part 1 | 101 | April 7, 2018, 11:12 p.m. |
| Factorization Cipher — Part 1 | 100 | April 7, 2018, 9:50 p.m. |
| A hidden word | 100 | April 7, 2018, 9:36 p.m. |
| Letter to the Templars — Part 3 | 1,097 | April 7, 2018, 9:08 p.m. |
| Letter to the Templars — Part 2 | 100 | April 7, 2018, 8:11 p.m. |
| Letter to the Templars — Part 1 | 100 | April 7, 2018, 8:08 p.m. |
| Caesar Encryption | 100 | April 7, 2018, 7:23 p.m. |
| Number Sequence — Part 6 | 100 | April 2, 2018, 2:25 a.m. |
| Number Sequence — Part 4 | 100 | April 1, 2018, 11:29 p.m. |
| Number Sequence — Part 3 | 100 | April 1, 2018, 11:26 p.m. |
| Number Sequence | 100 | April 1, 2018, 11:24 p.m. |
| Number Sequence — Part 2 | 100 | April 1, 2018, 11:22 p.m. |
| Number Sequence — Part 8 | 100 | April 1, 2018, 11:21 p.m. |
| Grille Cipher | 100 | April 1, 2018, 8:08 p.m. |
| How do you become a big cryptographer? | 100 | April 1, 2018, 7:51 p.m. |
| Beaver Code | 100 | March 31, 2018, 9:50 p.m. |
| Original Caesar Cipher | 100 | March 31, 2018, 8:53 p.m. |