| Autokey Cipher | 104 | Oct. 20, 2018, 10:17 a.m. |
| Number Sequence — Part 9 | 111 | Nov. 25, 2017, 8:40 a.m. |
| Number Sequence — Part 8 | 125 | Sept. 18, 2015, 4:51 a.m. |
| Number Sequence — Part 6 | 117 | March 29, 2015, 10:24 a.m. |
| Heartbleed — Part 1 | 150 | Aug. 29, 2014, 6:21 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 133 | Sept. 29, 2013, 12:31 p.m. |
| Nils away on travel | 133 | Aug. 11, 2013, 11:08 a.m. |
| Snow White and the seven dwarfs | 133 | April 22, 2013, 11:27 a.m. |
| Enigma Messages | 133 | Jan. 25, 2013, 9:54 p.m. |
| A hidden word | 200 | Jan. 7, 2013, 6:49 a.m. |
| Enigma Part 1 | 1,128 | Oct. 28, 2012, 3:11 p.m. |
| Beaver Code | 101 | Oct. 27, 2012, 10:15 p.m. |
| Factorization Cipher — Part 1 | 100 | Oct. 27, 2012, 9:08 a.m. |
| Letter to the Templars — Part 3 | 2,000 | Oct. 9, 2012, 6:18 p.m. |
| Letter to the Templars — Part 2 | 200 | July 31, 2012, 6:18 p.m. |
| Letter to the Templars — Part 1 | 200 | July 17, 2012, 8:28 p.m. |
| Number Sequence — Part 4 | 114 | April 25, 2012, 6:15 a.m. |
| Number Sequence — Part 3 | 200 | March 31, 2012, 8:06 a.m. |
| ECDH-Key Exchange for Beginners | 133 | Feb. 26, 2012, 4:55 p.m. |
| A really long number sequence | 1,237 | Dec. 6, 2011, 3 p.m. |
| Grille Cipher | 200 | Oct. 15, 2011, 1:48 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,269 | Sept. 21, 2011, 1:21 p.m. |
| Alice's Birthday Party (Part 2) | 1,160 | Sept. 20, 2011, 2:51 p.m. |
| Alice's Birthday Party (Part 1) | 1,161 | Sept. 19, 2011, 12:04 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 200 | Sept. 9, 2011, 11:43 a.m. |
| Pigpen with a twist — Part 3 | 1,547 | Sept. 8, 2011, 7:55 p.m. |
| Pigpen with a twist — Part 1 | 200 | Sept. 5, 2011, 10:17 p.m. |
| Modified Caesar Cipher | 125 | Sept. 5, 2011, 7:08 p.m. |
| Number Sequence — Part 2 | 150 | July 12, 2011, 3:50 p.m. |
| Kaskade-S/T — Part 1 | 102 | May 6, 2011, 12:04 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,187 | May 4, 2011, 6:08 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,187 | May 4, 2011, 10:29 a.m. |
| Cracking SHA1-Hashed Passwords | 1,485 | April 14, 2011, 2:25 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 114 | April 13, 2011, 12:30 p.m. |
| Original Caesar Cipher | 117 | Dec. 20, 2010, 2:48 p.m. |
| Molehunt (Part 2/3) | 105 | Nov. 10, 2010, 2:55 p.m. |
| Molehunt (Part 1/3) | 105 | Nov. 10, 2010, 2:18 p.m. |
| Caesar Encryption | 107 | Nov. 5, 2010, 1:17 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 107 | Nov. 5, 2010, 12:59 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 107 | Nov. 5, 2010, 12:41 p.m. |
| Number Sequence | 120 | Oct. 18, 2010, 4:27 p.m. |
Gold0
Silver2
Bronze1
