| Hill Cipher with Sudoku Key | 100 | March 26, 2014, 9:41 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 105 | March 24, 2014, 7:20 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 105 | March 24, 2014, 7:16 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 105 | March 24, 2014, 7:11 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 101 | March 24, 2014, 7:02 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 101 | March 24, 2014, 6:38 p.m. |
| Nils away on travel | 100 | March 23, 2014, 11:32 p.m. |
| From Russia with Love | 101 | March 22, 2014, 6:27 p.m. |
| Playfair Encryption | 100 | May 13, 2013, 9:32 p.m. |
| Kaskade-S/T — Part 1 | 100 | May 1, 2013, 1:56 p.m. |
| Double Columnar Transposition | 100 | April 24, 2013, 11:38 p.m. |
| Snow White and the seven dwarfs | 120 | April 24, 2013, 11:02 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | April 19, 2013, 11:57 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | April 19, 2013, 5:58 p.m. |
| A really long number sequence | 1,137 | April 17, 2013, 11:10 p.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,121 | April 17, 2013, midnight |
| ECDH-Key Exchange for Beginners | 100 | April 12, 2013, 10:10 a.m. |
| ADFGVX — Part 1 | 100 | April 10, 2013, 9:26 p.m. |
| ADFGVX — Part 2 | 100 | April 10, 2013, 9:12 p.m. |
| Enigma Part 1 | 1,122 | April 5, 2013, midnight |
| Enigma Part 2 | 1,122 | April 4, 2013, 11:39 p.m. |
| Turing Bombe Enigma I | 100 | April 4, 2013, 8:51 p.m. |
| Enigma Combinatorics | 100 | April 3, 2013, 10:31 p.m. |
| How do you become a big cryptographer? | 100 | April 1, 2013, 8:22 p.m. |
| Cascading Encryption — Part 1/3 | 102 | March 28, 2013, 10:30 p.m. |
| Pigpen with a twist — Part 1 | 100 | March 21, 2013, 3:18 p.m. |
| Number Sequence — Part 4 | 100 | March 20, 2013, 10:08 a.m. |
| Number Sequence — Part 3 | 100 | March 20, 2013, 9:52 a.m. |
| The Book Code: A Challenge for Bookworms | 100 | March 20, 2013, 9:33 a.m. |
| Molehunt (Part 3/3) | 1,123 | March 18, 2013, 6:21 p.m. |
| Molehunt (Part 2/3) | 100 | March 18, 2013, 3:26 p.m. |
| Molehunt (Part 1/3) | 100 | March 18, 2013, 2:51 p.m. |
| A hidden word | 101 | March 16, 2013, 1:03 p.m. |
| Reserve Hand Procedure — Part 1 | 110 | March 16, 2013, 12:52 p.m. |
| Letter to the Templars — Part 3 | 1,201 | March 16, 2013, 8:58 a.m. |
| Keyshanc — Part 1 | 1,217 | Sept. 20, 2012, 12:17 a.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,176 | Sept. 18, 2012, 2:20 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,130 | Sept. 18, 2012, 1:30 a.m. |
| Hybrid Encryption I | 1,131 | Sept. 16, 2012, 4:56 p.m. |
| RSA: Two different keys — same ciphertext | 1,153 | Sept. 16, 2012, 3:57 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,130 | Sept. 16, 2012, 2:29 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,151 | Sept. 16, 2012, 1:15 p.m. |
| Alice's Birthday Party (Part 2) | 1,130 | Sept. 16, 2012, 12:40 p.m. |
| Alice's Birthday Party (Part 1) | 1,130 | Sept. 15, 2012, 1:34 p.m. |
| BCR code (Book-Caesar-RSA) | 1,824 | Sept. 13, 2012, 10:38 p.m. |
| Cracking SHA1-Hashed Passwords | 1,142 | Sept. 13, 2012, 12:31 p.m. |
| Beaver Code | 103 | Sept. 12, 2012, 4:41 p.m. |
| Factorization Cipher — Part 3 | 1,176 | Sept. 12, 2012, 2:43 a.m. |
| Factorization Cipher — Part 2 | 1,169 | Sept. 10, 2012, 4:12 p.m. |
| Letter to the Templars — Part 2 | 102 | Sept. 9, 2012, 10:13 p.m. |
| Letter to the Templars — Part 1 | 102 | Sept. 9, 2012, 8:14 p.m. |
| Grille Cipher | 100 | Sept. 9, 2012, 7:44 p.m. |
| Number Sequence — Part 2 | 100 | Sept. 9, 2012, 6:32 p.m. |
| Factorization Cipher — Part 1 | 100 | Sept. 5, 2012, 3:32 p.m. |
| ¿No Hablas Español? No problemo! | 101 | Sept. 5, 2012, 2:15 p.m. |
| One-Time Pad with Flaws | 100 | Sept. 5, 2012, 12:41 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Sept. 4, 2012, 8:41 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Sept. 4, 2012, 6:56 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Sept. 4, 2012, 6:26 p.m. |
| Monoalphabetic Substitution | 100 | Sept. 3, 2012, 9:38 p.m. |
| Modified Caesar Cipher | 100 | Sept. 3, 2012, 2:35 a.m. |
| Caesar Encryption | 100 | Sept. 3, 2012, 12:05 a.m. |
| Original Caesar Cipher | 100 | Sept. 2, 2012, 11:18 p.m. |
| Number Sequence | 100 | Sept. 2, 2012, 10:16 p.m. |
Gold0
Silver0
Bronze0
