| Advent-Challenge — Part 1 | 101 | June 7, 2018, 10:31 p.m. |
| Number Sequence — Part 10 | 102 | June 7, 2018, 10:01 p.m. |
| Playfair with hints about the grid | 100 | Aug. 27, 2017, 3:29 p.m. |
| Playfair Encryption | 100 | Aug. 27, 2017, 3:20 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | Aug. 25, 2017, 11:08 p.m. |
| Enigma Messages | 100 | Aug. 24, 2017, 1:54 p.m. |
| Enigma Part 1 | 1,092 | Aug. 23, 2017, 6:21 p.m. |
| Alice's Birthday Party (Part 2) | 1,092 | Aug. 23, 2017, 3:28 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,095 | Aug. 23, 2017, 1:27 p.m. |
| Image Noise | 100 | Aug. 21, 2017, 9:06 a.m. |
| Number Sequence — Part 3 | 100 | Aug. 20, 2017, 12:37 a.m. |
| The Last Note | 100 | Jan. 11, 2016, 1:35 p.m. |
| Number Sequence — Part 8 | 102 | Nov. 5, 2015, 8:03 a.m. |
| Heartbleed — Part 2 | 100 | May 9, 2015, 12:51 p.m. |
| A hidden word — Part 2 | 104 | May 8, 2015, 9:52 p.m. |
| Number Sequence — Part 7 | 102 | May 8, 2015, 8:40 p.m. |
| M-138 — Part 2 | 1,444 | Jan. 5, 2015, 9:45 p.m. |
| M-138 — Part 1 | 108 | Jan. 5, 2015, 1:40 p.m. |
| An Invisible Message | 100 | March 17, 2014, 12:22 p.m. |
| Hill Cipher with Sudoku Key | 101 | March 12, 2014, 11:37 a.m. |
| Hybrid Encryption I | 1,112 | March 12, 2014, 8:35 a.m. |
| Keyshanc — Part 2 | 1,133 | March 11, 2014, 10:11 a.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,127 | March 5, 2014, 1:59 p.m. |
| How do you become a big cryptographer? | 100 | March 5, 2014, 11:17 a.m. |
| RSA: Two different keys — same ciphertext | 1,121 | March 4, 2014, 2:41 p.m. |
| Factorization Cipher — Part 2 | 1,125 | March 3, 2014, 2:59 p.m. |
| Alice's Birthday Party (Part 1) | 1,111 | March 3, 2014, 1:09 p.m. |
| BCR code (Book-Caesar-RSA) | 1,141 | Feb. 24, 2014, 3:15 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,112 | Feb. 21, 2014, 2:13 p.m. |
| Double Columnar Transposition | 100 | Feb. 12, 2014, 4:39 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Feb. 11, 2014, 9:06 a.m. |
| Kaskade-S/T — Part 2 | 1,116 | Feb. 8, 2014, 8:08 a.m. |
| Kaskade-S/T — Part 1 | 100 | Feb. 6, 2014, 10:54 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Feb. 3, 2014, 12:56 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Jan. 31, 2014, 1:42 p.m. |
| Molehunt (Part 3/3) | 1,112 | Jan. 31, 2014, 10:57 a.m. |
| Molehunt (Part 2/3) | 100 | Jan. 31, 2014, 8:58 a.m. |
| Keyshanc — Part 1 | 1,135 | Jan. 30, 2014, 9:45 p.m. |
| Molehunt (Part 1/3) | 100 | Jan. 30, 2014, 9:37 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,112 | Jan. 30, 2014, 8:34 a.m. |
| Trifid Cipher | 101 | Jan. 22, 2014, 1:23 p.m. |
| An 'unhearable' message | 100 | Jan. 21, 2014, 4:28 p.m. |
| Pigpen with a twist — Part 1 | 100 | Jan. 21, 2014, 10:55 a.m. |
| Classical Ciphers^3 | 100 | Jan. 20, 2014, 5:23 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Jan. 15, 2014, 2:03 p.m. |
| One-Time Pad with Flaws | 100 | Jan. 14, 2014, 9:59 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | Jan. 5, 2014, 9:02 p.m. |
| Number Sequence — Part 4 | 100 | Jan. 5, 2014, 7:49 p.m. |
| Number Sequence — Part 2 | 100 | Jan. 5, 2014, 10:17 a.m. |
| Number Sequence | 100 | Jan. 5, 2014, 9:42 a.m. |
| From Russia with Love | 101 | Jan. 5, 2014, 8:39 a.m. |
| Cracking SHA1-Hashed Passwords | 1,118 | Jan. 5, 2014, 5:32 a.m. |
| Snow White and the seven dwarfs | 100 | Jan. 2, 2014, 9:39 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Jan. 2, 2014, 3:13 p.m. |
| Modified Caesar Cipher | 100 | Jan. 2, 2014, 11:39 a.m. |
| Factorization Cipher — Part 1 | 100 | Jan. 1, 2014, 10:10 p.m. |
| A hidden word | 100 | Dec. 31, 2013, 9:48 a.m. |
| Grille Cipher | 100 | Dec. 31, 2013, 9:30 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Dec. 30, 2013, 9:18 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Dec. 30, 2013, 1:52 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Dec. 30, 2013, 7:29 a.m. |
| Letter to the Templars — Part 3 | 1,148 | Dec. 29, 2013, 11 p.m. |
| Letter to the Templars — Part 2 | 100 | Dec. 29, 2013, 10:36 p.m. |
| Letter to the Templars — Part 1 | 100 | Dec. 29, 2013, 9:08 a.m. |
| Beaver Code | 100 | Dec. 26, 2013, 8:52 a.m. |
| Monoalphabetic Substitution | 100 | Dec. 26, 2013, 8:20 a.m. |
| Caesar Encryption | 100 | Dec. 23, 2013, 9:40 a.m. |
| Original Caesar Cipher | 100 | Dec. 23, 2013, 9:07 a.m. |
Gold0
Silver0
Bronze0
