| Advent-Challenge — Part 1 | 133 | Dec. 11, 2017, 2:07 p.m. |
| Number Sequence — Part 9 | 107 | Nov. 30, 2017, 6:57 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,094 | Jan. 10, 2017, 4:52 p.m. |
| Ku Klux Klan | 1,000 | Sept. 20, 2016, 8 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,102 | Aug. 17, 2016, 8:39 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,102 | Aug. 17, 2016, 8:30 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,097 | April 27, 2016, 7:15 p.m. |
| New Year's Greetings — Part 5 | 1,330 | April 21, 2016, 7:19 p.m. |
| New Year's Greetings — Part 4 | 104 | April 13, 2016, 6:32 a.m. |
| New Year's Greetings — Part 3 | 105 | April 11, 2016, 10:55 p.m. |
| New Year's Greetings — Part 2 | 105 | April 11, 2016, 9:33 p.m. |
| New Year's Greetings — Part 1 | 105 | April 11, 2016, 8:50 p.m. |
| Factorization Cipher — Part 3 | 1,105 | March 7, 2016, 8:37 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,106 | Feb. 26, 2016, 8:26 p.m. |
| RSA: Two different keys — same ciphertext | 1,103 | Feb. 22, 2016, 11:31 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,102 | Feb. 19, 2016, 12:06 p.m. |
| Alice's Birthday Party (Part 2) | 1,098 | Feb. 17, 2016, 7:11 p.m. |
| Enigma Part 2 | 1,098 | Feb. 8, 2016, 11:28 p.m. |
| Enigma Part 1 | 1,098 | Feb. 8, 2016, 8:31 p.m. |
| Heartbleed — Part 3 | 1,142 | Feb. 1, 2016, 10:06 p.m. |
| Molehunt (Part 3/3) | 1,099 | Jan. 11, 2016, 5:18 p.m. |
| Heartbleed — Part 2 | 100 | Dec. 15, 2015, 9:49 p.m. |
| Heartbleed — Part 1 | 100 | Dec. 15, 2015, 8:22 p.m. |
| An 'unhearable' message | 100 | Dec. 11, 2015, 2:15 p.m. |
| Image Noise | 200 | Nov. 21, 2015, 8:19 p.m. |
| News from Castle Mansfeld | 150 | Nov. 14, 2015, 9:45 p.m. |
| Weakened Granit — Part 1 | 150 | Sept. 25, 2015, 4:47 p.m. |
| Number Sequence — Part 8 | 150 | Sept. 15, 2015, 1:12 p.m. |
| Cracking SHA1-Hashed Passwords | 1,104 | July 14, 2015, 6:43 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | July 12, 2015, 8:53 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | July 9, 2015, 9:48 p.m. |
| Playfair Encryption | 100 | June 26, 2015, 9:47 a.m. |
| Enigma Messages | 100 | May 29, 2015, 4:10 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | May 28, 2015, 7:26 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | May 28, 2015, 7:21 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | May 28, 2015, 7:13 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | May 27, 2015, 11:09 p.m. |
| Turing Bombe Enigma I | 100 | May 16, 2015, 12:34 a.m. |
| Number Sequence — Part 7 | 102 | May 9, 2015, 8:31 a.m. |
| A hidden word — Part 2 | 200 | April 17, 2015, 1:34 p.m. |
| Number Sequence — Part 6 | 104 | April 14, 2015, 6:36 p.m. |
| An Invisible Message | 100 | April 8, 2015, 7:41 p.m. |
| ¿No Hablas Español? No problemo! | 100 | April 4, 2015, 7:53 p.m. |
| Number Sequence — Part 5 | 100 | April 3, 2015, 5:52 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | April 2, 2015, 6:42 p.m. |
| Strange Message from Thessaloniki | 100 | March 26, 2015, 9:56 p.m. |
| Recycled One-Time Pad | 100 | March 26, 2015, 7:21 p.m. |
| Hill Cipher with Sudoku Key | 100 | March 21, 2015, 8:10 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | March 20, 2015, 5:55 p.m. |
| Nils away on travel | 100 | March 13, 2015, 9:49 p.m. |
| How do you become a big cryptographer? | 100 | March 13, 2015, 6:01 p.m. |
| Modified Caesar Cipher | 100 | March 4, 2015, 4:23 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Feb. 27, 2015, 1:05 p.m. |
| ADFGVX — Part 1 | 100 | Feb. 25, 2015, 7:06 p.m. |
| ADFGVX — Part 2 | 100 | Feb. 25, 2015, 4:50 p.m. |
| Cascading Encryption — Part 1/3 | 100 | Feb. 18, 2015, 7:49 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Feb. 3, 2015, 3:23 p.m. |
| Alice's Birthday Party (Part 1) | 1,104 | Jan. 29, 2015, 8:42 p.m. |
| Factorization Cipher — Part 2 | 1,114 | Jan. 28, 2015, 11:13 p.m. |
| Music Code — Part 2 | 1,109 | Jan. 22, 2015, 10:49 p.m. |
| Factorization Cipher — Part 1 | 100 | Jan. 20, 2015, 1:34 p.m. |
| Music Code — Part 1 | 100 | Jan. 13, 2015, 12:03 p.m. |
| ECDH-Key Exchange for Beginners | 100 | Jan. 6, 2015, 3:49 p.m. |
| M-138 — Part 2 | 1,547 | Dec. 31, 2014, 12:11 a.m. |
| M-138 — Part 1 | 150 | Dec. 25, 2014, 4:30 p.m. |
| Kaskade-S/T — Part 1 | 100 | Nov. 12, 2014, 11:54 a.m. |
| Double Columnar Transposition | 100 | Nov. 11, 2014, 10:11 a.m. |
| Letter to the Templars — Part 2 | 100 | Nov. 10, 2014, 5:19 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Nov. 7, 2014, 3:35 p.m. |
| A hidden word | 100 | Nov. 6, 2014, 2:06 p.m. |
| Grille Cipher | 100 | Nov. 6, 2014, 11:18 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Nov. 4, 2014, 4:31 p.m. |
| Playfair with hints about the grid | 100 | Oct. 31, 2014, 11:12 p.m. |
| Pigpen with a twist — Part 1 | 100 | Oct. 30, 2014, 6:36 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Oct. 25, 2014, 12:23 a.m. |
| Number Sequence — Part 4 | 100 | Oct. 8, 2014, 11:03 a.m. |
| Number Sequence — Part 3 | 100 | Oct. 8, 2014, 10:11 a.m. |
| Number Sequence — Part 2 | 100 | Oct. 8, 2014, 8:18 a.m. |
| Enigma Combinatorics | 100 | Oct. 7, 2014, 11:59 a.m. |
| A Secret Message from Castle Mansfeld | 100 | Sept. 28, 2014, 5:24 p.m. |
| The Last Note | 200 | Sept. 23, 2014, 7:32 p.m. |
| Letter to the Templars — Part 3 | 1,130 | Sept. 20, 2014, 2:50 a.m. |
| Double Column Transposition — Part 4 | 1,217 | Sept. 18, 2014, 2:59 p.m. |
| Original Caesar Cipher | 100 | Sept. 15, 2014, 4:57 p.m. |
| Molehunt (Part 2/3) | 100 | Sept. 15, 2014, 2:19 p.m. |
| Molehunt (Part 1/3) | 100 | Sept. 15, 2014, 11:01 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Sept. 12, 2014, 11:06 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Sept. 12, 2014, 10:09 a.m. |
| One-Time Pad with Flaws | 100 | Sept. 11, 2014, 4:27 p.m. |
| Zodiac Cipher | 100 | Sept. 5, 2014, 1:37 p.m. |
| Caesar Encryption | 100 | Sept. 5, 2014, 9:50 a.m. |
| From Russia with Love | 100 | Sept. 4, 2014, 3:57 p.m. |
| Letter to the Templars — Part 1 | 100 | Sept. 4, 2014, 11:25 a.m. |
| Beaver Code | 100 | Sept. 3, 2014, 11:34 a.m. |
| Trifid Cipher | 100 | Sept. 2, 2014, 9:12 p.m. |
| Snow White and the seven dwarfs | 100 | Sept. 1, 2014, 7:42 p.m. |
| Classical Ciphers^3 | 100 | Aug. 31, 2014, 2:05 p.m. |
| Monoalphabetic Substitution | 100 | Aug. 22, 2014, 9:22 a.m. |
| Number Sequence | 100 | Aug. 21, 2014, 9:32 a.m. |
Gold0
Silver0
Bronze0
