| A really long number sequence | 1,130 | Aug. 18, 2013, 11:28 a.m. |
| Turing Bombe Enigma I | 100 | Aug. 17, 2013, 10:09 p.m. |
| Pigpen with a twist — Part 1 | 100 | Aug. 16, 2013, 6:21 p.m. |
| Playfair with hints about the grid | 100 | Aug. 16, 2013, 2:47 p.m. |
| Enigma Combinatorics | 100 | Aug. 15, 2013, 11:12 p.m. |
| How do you become a big cryptographer? | 100 | Aug. 15, 2013, 1:33 p.m. |
| Nils away on travel | 114 | Aug. 15, 2013, 11:25 a.m. |
| RSA Factoring Challenge: RSA-704 | 0 | Aug. 15, 2013, 11:16 a.m. |
| ADFGVX — Part 2 | 100 | Aug. 15, 2013, 11:04 a.m. |
| ADFGVX — Part 1 | 100 | Aug. 15, 2013, 10:20 a.m. |
| Factorization Cipher — Part 3 | 1,137 | Aug. 13, 2013, 5:45 p.m. |
| Classical Ciphers^3 | 100 | July 29, 2013, 12:54 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | July 28, 2013, 8:08 p.m. |
| Molehunt (Part 3/3) | 1,118 | July 26, 2013, 9:25 p.m. |
| Molehunt (Part 2/3) | 100 | July 26, 2013, 8:29 p.m. |
| Molehunt (Part 1/3) | 100 | July 26, 2013, 8:08 p.m. |
| Reserve Hand Procedure — Part 1 | 101 | July 25, 2013, 9:23 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | July 25, 2013, 2:48 p.m. |
| Factorization Cipher — Part 2 | 1,136 | July 24, 2013, 2:39 p.m. |
| RSA: Two different keys — same ciphertext | 1,130 | July 24, 2013, 12:50 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,118 | July 24, 2013, 10:38 a.m. |
| Hybrid Encryption I | 1,118 | July 23, 2013, 7:25 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,118 | July 23, 2013, 5:19 p.m. |
| Modified Caesar Cipher | 100 | July 23, 2013, 2:03 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,129 | July 22, 2013, 6:46 p.m. |
| Snow White and the seven dwarfs | 101 | July 22, 2013, 11:53 a.m. |
| Alice's Birthday Party (Part 2) | 1,118 | July 22, 2013, 11:22 a.m. |
| Alice's Birthday Party (Part 1) | 1,118 | July 22, 2013, 12:10 a.m. |
| A hidden word | 101 | July 21, 2013, 8:06 p.m. |
| Factorization Cipher — Part 1 | 100 | July 20, 2013, 1:48 p.m. |
| Grille Cipher | 100 | July 19, 2013, 1:34 p.m. |
| Cracking SHA1-Hashed Passwords | 1,124 | July 18, 2013, 10:56 p.m. |
| One-Time Pad with Flaws | 100 | July 18, 2013, 10:41 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | July 18, 2013, 7:21 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | July 18, 2013, 2:51 p.m. |
| Letter to the Templars — Part 3 | 1,170 | July 18, 2013, 2:22 p.m. |
| Letter to the Templars — Part 2 | 100 | July 18, 2013, 1:17 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | July 18, 2013, 11:09 a.m. |
| Letter to the Templars — Part 1 | 100 | July 18, 2013, 10:37 a.m. |
| Beaver Code | 100 | July 18, 2013, 9:40 a.m. |
| Monoalphabetic Substitution | 100 | July 18, 2013, 9:15 a.m. |
| Caesar Encryption | 100 | July 17, 2013, 6:59 p.m. |
| Number Sequence — Part 4 | 100 | July 17, 2013, 6:25 p.m. |
| Number Sequence — Part 3 | 100 | July 17, 2013, 6:16 p.m. |
| Number Sequence — Part 2 | 100 | July 17, 2013, 6:10 p.m. |
| Original Caesar Cipher | 100 | July 17, 2013, 6:06 p.m. |
| Number Sequence | 100 | July 17, 2013, 6:05 p.m. |
Gold0
Silver0
Bronze0
