| Molehunt (Part 1/3) | 100 | July 10, 2015, 12:14 p.m. |
| Playfair with hints about the grid | 100 | July 9, 2015, 2:46 p.m. |
| Playfair Encryption | 100 | July 9, 2015, 2:32 p.m. |
| Number Sequence — Part 6 | 113 | March 30, 2015, 2:30 p.m. |
| M-138 — Part 2 | 1,444 | Jan. 5, 2015, 3:43 p.m. |
| M-138 — Part 1 | 108 | Jan. 4, 2015, 11:46 a.m. |
| Double Columnar Transposition | 100 | Sept. 11, 2014, 8:20 a.m. |
| Heartbleed — Part 3 | 1,725 | Aug. 31, 2014, 1:03 p.m. |
| Heartbleed — Part 2 | 133 | Aug. 31, 2014, 10:17 a.m. |
| Heartbleed — Part 1 | 150 | Aug. 29, 2014, 5:23 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 101 | March 9, 2014, 12:26 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 101 | March 8, 2014, 6:12 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 133 | March 8, 2014, 1:58 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 133 | March 8, 2014, 1:34 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 133 | March 8, 2014, 1:14 p.m. |
| From Russia with Love | 133 | Sept. 6, 2013, 8:44 p.m. |
| Nils away on travel | 125 | Aug. 11, 2013, 5:30 p.m. |
| ADFGVX — Part 2 | 100 | June 16, 2013, 3:46 p.m. |
| Snow White and the seven dwarfs | 133 | April 23, 2013, 4:31 a.m. |
| Cascading Encryption — Part 1/3 | 101 | April 1, 2013, 4:01 p.m. |
| Reserve Hand Procedure — Part 1 | 109 | March 17, 2013, 12:29 p.m. |
| A hidden word | 200 | Jan. 7, 2013, 6:23 a.m. |
| Letter to the Templars — Part 3 | 1,725 | Oct. 12, 2012, 9 a.m. |
| BCR code (Book-Caesar-RSA) | 1,576 | Sept. 18, 2012, 7:51 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Sept. 12, 2012, 8 a.m. |
| Unconcealed RSA messages | 1,165 | Sept. 3, 2012, 7:50 p.m. |
| Unusual encryption using a diophantine equation | 1,158 | Aug. 27, 2012, 9:49 a.m. |
| Enigma Part 1 | 1,132 | Aug. 25, 2012, 6:07 p.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,132 | Aug. 22, 2012, 6:48 p.m. |
| Beaver Code | 150 | Aug. 15, 2012, 2:01 p.m. |
| Classical Ciphers^3 | 100 | Aug. 2, 2012, 5:54 p.m. |
| Letter to the Templars — Part 2 | 200 | July 31, 2012, 8:33 a.m. |
| Keyshanc — Part 2 | 1,270 | July 20, 2012, 7:59 p.m. |
| Letter to the Templars — Part 1 | 200 | July 17, 2012, 3:11 p.m. |
| Keyshanc — Part 1 | 1,278 | July 14, 2012, 9:34 p.m. |
| Grille Cipher | 100 | May 10, 2012, 1:49 p.m. |
| Turing Bombe Enigma I | 100 | May 8, 2012, 5:48 p.m. |
| A really long number sequence | 1,177 | May 7, 2012, 9:31 a.m. |
| Modified Caesar Cipher | 100 | May 6, 2012, 1:24 p.m. |
| Number Sequence — Part 4 | 114 | April 25, 2012, 2:21 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,256 | April 21, 2012, 6:04 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | April 21, 2012, 1:57 p.m. |
| One-Time Pad with Flaws | 100 | April 20, 2012, 12:52 p.m. |
| ¿No Hablas Español? No problemo! | 200 | April 18, 2012, 9:53 p.m. |
| Smartcard RSA | 1,140 | April 18, 2012, 5:14 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,238 | April 16, 2012, 9:09 a.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,147 | April 14, 2012, 3:41 p.m. |
| Enigma Part 2 | 1,140 | April 7, 2012, 7:06 p.m. |
| Number Sequence — Part 3 | 200 | March 31, 2012, 11:15 a.m. |
| Factorization Cipher — Part 3 | 1,254 | March 18, 2012, 4:59 p.m. |
| Factorization Cipher — Part 2 | 1,228 | March 14, 2012, 8:51 p.m. |
| Factorization Cipher — Part 1 | 101 | March 11, 2012, 5:10 p.m. |
| ECDH-Key Exchange for Beginners | 108 | March 7, 2012, 3:10 p.m. |
| Hybrid Encryption I | 1,158 | Oct. 30, 2011, 11:38 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,248 | Oct. 9, 2011, 2:48 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,158 | Oct. 9, 2011, 1 p.m. |
| Alice's Birthday Party (Part 2) | 1,158 | Oct. 8, 2011, 12:02 p.m. |
| Alice's Birthday Party (Part 1) | 1,158 | Oct. 7, 2011, 10:01 a.m. |
| RSA: Two different keys — same ciphertext | 1,286 | Oct. 3, 2011, 5:37 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 150 | Sept. 10, 2011, 12:53 p.m. |
| Number Sequence — Part 2 | 125 | July 15, 2011, 2:21 p.m. |
| Cracking SHA1-Hashed Passwords | 1,234 | July 9, 2011, 2:26 p.m. |
| Original Caesar Cipher | 106 | Dec. 31, 2010, 9:58 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,502 | Oct. 23, 2010, 11:47 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 150 | Oct. 22, 2010, 9:56 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 150 | Oct. 22, 2010, 9:12 p.m. |
| Caesar Encryption | 200 | Oct. 22, 2010, 4:30 p.m. |
| Number Sequence | 114 | Oct. 21, 2010, 6:28 a.m. |
| Monoalphabetic Substitution | 133 | Oct. 16, 2010, 6:06 p.m. |
Gold0
Silver0
Bronze0
