| The Syllabary Cipher – Part 1 | 101 | March 3, 2023, 6:59 p.m. |
| Advent Challenge — Part 4 | 1,099 | March 3, 2023, 1:43 p.m. |
| Advent Challenge — Part 3 | 1,099 | Feb. 23, 2023, 8:08 p.m. |
| Advent-Challenge — Part 2 | 1,099 | Feb. 23, 2023, 3:06 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | Feb. 23, 2023, 12:11 p.m. |
| Advent-Challenge — Part 1 | 100 | Feb. 22, 2023, 7:24 p.m. |
| M-138 — Part 3 | 1,088 | Feb. 19, 2023, 11:05 p.m. |
| Pigpen with a twist — Part 1 | 100 | Feb. 19, 2023, 9:43 p.m. |
| M-138 — Part 2 | 1,088 | Feb. 19, 2023, 8:10 p.m. |
| M-138 — Part 1 | 100 | Feb. 19, 2023, 1:48 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Feb. 19, 2023, 12:43 p.m. |
| Alberti Challenge — Part 1 | 100 | Feb. 19, 2023, 10:42 a.m. |
| New Year's Greetings — Part 4 | 117 | March 26, 2016, 10:41 p.m. |
| New Year's Greetings — Part 3 | 117 | March 26, 2016, 8:39 p.m. |
| New Year's Greetings — Part 2 | 117 | March 26, 2016, 8:21 p.m. |
| Enigma Part 2 | 1,098 | March 26, 2016, 12:03 p.m. |
| New Year's Greetings — Part 1 | 120 | March 25, 2016, 1:34 p.m. |
| Enigma Part 1 | 1,098 | March 25, 2016, 11:05 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,098 | March 20, 2016, 3:06 p.m. |
| A really long number sequence | 1,103 | March 18, 2016, 10:34 a.m. |
| Hybrid Encryption I | 1,098 | March 15, 2016, 2:41 p.m. |
| RSA: Two different keys — same ciphertext | 1,102 | March 14, 2016, 10:14 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,098 | March 14, 2016, 5:19 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,102 | March 14, 2016, 3:06 p.m. |
| Alice's Birthday Party (Part 2) | 1,098 | March 14, 2016, 2:25 p.m. |
| Alice's Birthday Party (Part 1) | 1,098 | March 14, 2016, 12:26 p.m. |
| Factorization Cipher — Part 3 | 1,105 | March 10, 2016, 11:34 a.m. |
| Monoalphabetic Substitution | 100 | March 9, 2016, 8:59 a.m. |
| The Book Code: A Challenge for Bookworms | 100 | March 8, 2016, 5:41 p.m. |
| Factorization Cipher — Part 2 | 1,104 | March 8, 2016, 10:19 a.m. |
| How do you become a big cryptographer? | 100 | March 1, 2016, 5:01 p.m. |
| Grille Cipher | 100 | March 1, 2016, 3:59 p.m. |
| Factorization Cipher — Part 1 | 100 | Feb. 27, 2016, 7:55 p.m. |
| Snow White and the seven dwarfs | 100 | Feb. 27, 2016, 1:34 a.m. |
| Modified Caesar Cipher | 100 | Feb. 27, 2016, 1:12 a.m. |
| Beaver Code | 100 | Feb. 26, 2016, 6:24 p.m. |
| A hidden word | 100 | Feb. 26, 2016, 5:49 p.m. |
| Number Sequence — Part 8 | 101 | Feb. 26, 2016, 4:06 p.m. |
| Cracking SHA1-Hashed Passwords | 1,101 | Feb. 26, 2016, 9:05 a.m. |
| Letter to the Templars — Part 3 | 1,111 | Feb. 25, 2016, 4:53 p.m. |
| Letter to the Templars — Part 2 | 100 | Feb. 25, 2016, 4:09 p.m. |
| Letter to the Templars — Part 1 | 100 | Feb. 25, 2016, 3:29 p.m. |
| Number Sequence — Part 4 | 100 | Feb. 25, 2016, 1:32 p.m. |
| Number Sequence — Part 3 | 100 | Feb. 25, 2016, 1:12 p.m. |
| Caesar Encryption | 100 | Feb. 25, 2016, 10:35 a.m. |
| Original Caesar Cipher | 100 | Feb. 25, 2016, 9:12 a.m. |
| Number Sequence — Part 2 | 100 | Feb. 24, 2016, 11:51 p.m. |
| Number Sequence | 100 | Feb. 24, 2016, 10:22 p.m. |