| ASAC — A Strong(er) ADFGVX Cipher — Part 1 | 2,000 | July 9, 2016, 11:39 p.m. |
| Sigaba Part 1 | 1,096 | July 2, 2016, 7:47 p.m. |
| RSA with Special d | 13,331 | May 31, 2016, 6:56 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | May 30, 2016, 9:23 p.m. |
| Ku Klux Klan | 1,000 | May 26, 2016, 11:53 p.m. |
| Pigpen with a twist — Part 1 | 100 | May 23, 2016, 12:37 p.m. |
| How do you become a big cryptographer? | 100 | May 23, 2016, 11:19 a.m. |
| Akelarre Part 1 | 1,098 | May 3, 2016, 7:59 a.m. |
| New Year's Greetings — Part 5 | 1,330 | April 21, 2016, 9:37 p.m. |
| New Year's Greetings — Part 4 | 103 | April 21, 2016, 7:52 p.m. |
| New Year's Greetings — Part 3 | 103 | April 21, 2016, 7:12 p.m. |
| New Year's Greetings — Part 2 | 103 | April 21, 2016, 6:53 p.m. |
| New Year's Greetings — Part 1 | 103 | April 21, 2016, 6:41 p.m. |
| News from Castle Mansfeld | 101 | Jan. 28, 2016, 9:33 a.m. |
| Image Noise | 101 | Jan. 27, 2016, 10:25 p.m. |
| Purple 1 | 1,100 | Oct. 7, 2015, 4:31 a.m. |
| Lattice Part 1 | 1,103 | Sept. 26, 2015, 3:38 a.m. |
| Weakened Granit — Part 1 | 150 | Sept. 25, 2015, 9:47 p.m. |
| M-138 — Part 3 | 1,172 | Sept. 18, 2015, 4:25 a.m. |
| Weakened Handycipher — Part 3 | 1,216 | Sept. 14, 2015, 6:27 p.m. |
| Weakened Handycipher — Part 2 | 1,216 | Sept. 14, 2015, 6:26 p.m. |
| Number Sequence — Part 8 | 200 | Sept. 14, 2015, 6:23 p.m. |
| Spanish Strip Cipher — Part 2 | 1,141 | Sept. 12, 2015, 2:01 p.m. |
| Nils away on travel | 100 | Sept. 2, 2015, 5:27 p.m. |
| A hidden word — Part 2 | 101 | Sept. 2, 2015, 4:51 p.m. |
| Double Column Transposition — Part 3 | 1,145 | Sept. 2, 2015, 3:58 p.m. |
| Double Column Transposition — Part 4 | 1,146 | Sept. 2, 2015, 12:44 p.m. |
| Double Column Transposition — Part 2 | 1,145 | Sept. 2, 2015, 7:09 a.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,108 | Sept. 1, 2015, 1:31 p.m. |
| Weakened Handycipher — Part 1 | 1,229 | Aug. 22, 2015, 12:40 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | June 5, 2015, 1:11 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | June 4, 2015, 8:29 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | June 4, 2015, 7:46 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | June 4, 2015, 7:22 p.m. |
| The Last Note | 100 | June 3, 2015, 4:27 p.m. |
| Number Sequence — Part 6 | 101 | June 3, 2015, 1:54 p.m. |
| Heartbleed — Part 2 | 100 | May 29, 2015, 7:48 a.m. |
| Heartbleed — Part 1 | 100 | May 28, 2015, 1:28 p.m. |
| M-138 — Part 2 | 1,202 | May 28, 2015, 1:19 p.m. |
| M-138 — Part 1 | 101 | May 27, 2015, 9:09 p.m. |
| Spanish Strip Cipher — Part 1 | 1,254 | June 7, 2014, 4:21 p.m. |
| Trifid Cipher | 200 | Oct. 29, 2013, 2:26 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 200 | Sept. 26, 2013, 11:15 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Sept. 16, 2013, 3:19 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Sept. 15, 2013, 7:32 p.m. |
| Pigpen with a twist — Part 3 | 1,128 | Sept. 15, 2013, 4:15 p.m. |
| Pigpen with a twist — Part 2 | 1,128 | Sept. 15, 2013, 4:14 p.m. |
| Unusual encryption using a diophantine equation | 1,128 | Sept. 14, 2013, 10:26 a.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,116 | Sept. 13, 2013, 11:04 p.m. |
| An 'unhearable' message | 100 | Sept. 11, 2013, 2:59 a.m. |
| An Invisible Message | 100 | Sept. 10, 2013, 11:55 p.m. |
| Number Sequence — Part 3 | 100 | Sept. 10, 2013, 1:33 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Sept. 10, 2013, 11:55 a.m. |
| Zodiac Cipher | 100 | Sept. 9, 2013, 9:22 a.m. |
| Enigma Messages | 100 | Sept. 8, 2013, 7:13 p.m. |
| Music Code — Part 2 | 1,124 | Sept. 7, 2013, 9:52 p.m. |
| Music Code — Part 1 | 100 | Sept. 7, 2013, 9:51 p.m. |
| From Russia with Love | 133 | Sept. 7, 2013, 1:16 p.m. |
| Hill Cipher with Sudoku Key | 133 | Sept. 7, 2013, 12:07 p.m. |
| Recycled One-Time Pad | 100 | Sept. 2, 2013, 10:47 p.m. |
| Classical Ciphers^3 | 100 | Sept. 1, 2013, 4:40 p.m. |
| Cascading Encryption — Part 1/3 | 100 | Aug. 31, 2013, 12:33 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,134 | Aug. 30, 2013, 5:36 p.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,141 | Aug. 30, 2013, 5:08 p.m. |
| Molehunt (Part 3/3) | 1,117 | Aug. 30, 2013, 2:19 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Aug. 29, 2013, 11:40 p.m. |
| ADFGVX — Part 1 | 100 | Aug. 29, 2013, 7:30 p.m. |
| Molehunt (Part 2/3) | 100 | Aug. 29, 2013, 4:17 p.m. |
| Molehunt (Part 1/3) | 100 | Aug. 29, 2013, 3:38 p.m. |
| Double Columnar Transposition | 100 | Aug. 29, 2013, 12:49 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Aug. 28, 2013, 1:33 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Aug. 27, 2013, 9:54 p.m. |
| Enigma Part 1 | 1,117 | Aug. 27, 2013, 5:27 p.m. |
| Playfair with hints about the grid | 100 | Aug. 27, 2013, 4:30 p.m. |
| Playfair Encryption | 100 | Aug. 27, 2013, 4 p.m. |
| Enigma Part 2 | 1,117 | Aug. 25, 2013, 4:15 p.m. |
| Turing Bombe Enigma I | 100 | Aug. 24, 2013, 7:07 p.m. |
| Smartcard RSA | 1,117 | Aug. 15, 2013, 6:40 p.m. |
| Unconcealed RSA messages | 1,133 | Aug. 14, 2013, 7:02 p.m. |
| Keyshanc — Part 2 | 1,148 | Aug. 13, 2013, 6:46 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,120 | Aug. 11, 2013, 9:11 a.m. |
| Kaskade-S/T — Part 1 | 100 | Aug. 8, 2013, 8:58 p.m. |
| ECDH-Key Exchange for Beginners | 100 | Aug. 8, 2013, 8:31 p.m. |
| Monoalphabetic Substitution | 100 | Aug. 5, 2013, 9:29 p.m. |
| Typex — Part 2 | 1,217 | Aug. 2, 2013, 2:56 p.m. |
| Typex — Part 1 | 1,202 | Aug. 2, 2013, 2:55 p.m. |
| RSA: Two different keys — same ciphertext | 1,131 | July 15, 2013, 9:12 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,140 | July 15, 2013, 8:41 p.m. |
| CMEA 2 | 13,696 | July 15, 2013, 7:57 a.m. |
| CMEA 1 | 1,120 | July 15, 2013, 7:56 a.m. |
| ADFGVX — Part 2 | 100 | July 8, 2013, 7:58 a.m. |
| Keyshanc — Part 1 | 1,152 | July 8, 2013, 7:56 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,118 | July 6, 2013, 5:07 p.m. |
| ORYX Stream Cipher Part II | 1,118 | July 6, 2013, 4:58 p.m. |
| ORYX Stream Cipher Part I | 1,118 | July 6, 2013, 4:57 p.m. |
| Kaskade-S/T — Part 2 | 1,123 | July 6, 2013, 4:54 p.m. |
| Kaskade-S/T — Part 3 | 1,123 | July 6, 2013, 4:51 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,143 | July 6, 2013, 4:45 p.m. |
| Reserve Hand Procedure — Part 1 | 101 | July 6, 2013, 4:43 p.m. |
| Snow White and the seven dwarfs | 101 | July 6, 2013, 4:42 p.m. |
| ORYX Stream Cipher — Part 3 (revised) | 1,337 | July 6, 2013, 6:44 a.m. |
| Hybrid Encryption I | 1,125 | Feb. 7, 2013, 12:16 a.m. |
| A really long number sequence | 1,142 | Feb. 5, 2013, 8:11 p.m. |
| BCR code (Book-Caesar-RSA) | 1,206 | Feb. 5, 2013, 8:01 p.m. |
| Alice's Birthday Party (Part 2) | 1,124 | Feb. 3, 2013, 10:47 p.m. |
| Alice's Birthday Party (Part 1) | 1,124 | Feb. 3, 2013, 10:26 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,124 | Feb. 2, 2013, 9:49 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,139 | Feb. 2, 2013, 5:31 p.m. |
| Cracking SHA1-Hashed Passwords | 1,132 | Feb. 2, 2013, 12:20 p.m. |
| Factorization Cipher — Part 3 | 1,154 | Jan. 31, 2013, 6:27 p.m. |
| Factorization Cipher — Part 2 | 1,150 | Jan. 30, 2013, 4:51 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Jan. 28, 2013, 8:13 p.m. |
| Factorization Cipher — Part 1 | 100 | Jan. 27, 2013, 9:30 p.m. |
| Grille Cipher | 100 | Jan. 27, 2013, 11:19 a.m. |
| The Book Code: A Challenge for Bookworms | 100 | Jan. 26, 2013, 8:05 p.m. |
| One-Time Pad with Flaws | 100 | Jan. 26, 2013, 4:16 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Jan. 26, 2013, 12:48 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Jan. 25, 2013, 11:25 p.m. |
| Modified Caesar Cipher | 100 | Jan. 25, 2013, 9:55 p.m. |
| A hidden word | 125 | Jan. 9, 2013, 11:22 p.m. |
| Caesar Encryption | 100 | Jan. 9, 2013, 10:55 p.m. |
| Letter to the Templars — Part 3 | 1,236 | Jan. 9, 2013, 9:56 p.m. |
| Letter to the Templars — Part 2 | 101 | Jan. 9, 2013, 9:31 p.m. |
| Letter to the Templars — Part 1 | 101 | Jan. 9, 2013, 9:12 p.m. |
| Beaver Code | 101 | Jan. 9, 2013, 7:36 p.m. |
| Original Caesar Cipher | 100 | Jan. 9, 2013, 7:01 p.m. |
| Number Sequence — Part 4 | 100 | Dec. 31, 2012, 7:22 p.m. |
| Number Sequence — Part 2 | 100 | Dec. 31, 2012, 6:24 p.m. |
| Number Sequence | 100 | Dec. 31, 2012, 6:19 p.m. |
Gold0
Silver1
Bronze0
