| The SIGABA Challenge — Part 4 | 14,472 | Nov. 17, 2020, 9:28 a.m. |
| The SZ42 Challenge — Part 6 | 2,000 | Oct. 3, 2020, 4:38 p.m. |
| The Heavy T52 Sturgeon Challenge — Part 7 | 14,822 | Sept. 15, 2020, 2:25 p.m. |
| The Heavy T52 Sturgeon Challenge — Part 5 | 14,827 | Sept. 12, 2020, 2:33 p.m. |
| Polyhomophonic Substitution — Part 2 | 1,199 | Sept. 9, 2020, 5:32 a.m. |
| Polyhomophonic Substitution — Part 1 | 101 | Sept. 6, 2020, 10:24 a.m. |
| The SZ42 Challenge — Part 5 | 2,000 | Sept. 4, 2020, 10:44 a.m. |
| The SZ42 Challenge — Part 4 | 1,613 | Sept. 3, 2020, 5:10 a.m. |
| Handycipher made in love — Part 2 | 1,147 | Aug. 26, 2020, 7:12 a.m. |
| Handycipher made in love — Part 1 | 1,139 | Aug. 25, 2020, 6:38 p.m. |
| The SIGABA Challenge — Part 3 | 14,732 | Aug. 24, 2020, 4:19 a.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,140 | Aug. 23, 2020, 12:05 p.m. |
| Homophonic Encryption — Part 1 | 1,146 | Aug. 23, 2020, 5:43 a.m. |
| The Heavy T52 Sturgeon Challenge — Part 4 | 14,928 | Aug. 19, 2020, 6:43 a.m. |
| The SZ42 Challenge — Part 3 | 2,000 | Aug. 16, 2020, 7:01 a.m. |
| The SIGABA Challenge — Part 2 | 1,199 | Aug. 16, 2020, 5:07 a.m. |
| The SZ42 Challenge — Part 2 | 1,485 | Aug. 15, 2020, 3:15 p.m. |
| The SIGABA Challenge — Part 1 | 1,198 | Aug. 13, 2020, 1:47 p.m. |
| The T52 Sturgeon Challenge — Part 5 | 1,158 | Aug. 5, 2020, 2:47 p.m. |
| The T52 Sturgeon Challenge — Part 7 | 1,158 | Aug. 2, 2020, 4:21 a.m. |
| The T52 Sturgeon Challenge — Part 6 | 1,158 | Aug. 1, 2020, 4:24 p.m. |
| The T52 Sturgeon Challenge — Part 11 | 1,159 | July 29, 2020, 3:02 a.m. |
| The T52 Sturgeon Challenge — Part 12 | 1,159 | July 28, 2020, 4:06 p.m. |
| The SZ42 Challenge — Part 1 | 1,576 | July 28, 2020, 11:57 a.m. |
| The T52 Sturgeon Challenge — Part 10 | 1,159 | July 24, 2020, 11:17 a.m. |
| The T52 Sturgeon Challenge — Part 9 | 1,160 | July 23, 2020, 10:42 a.m. |
| The T52 Sturgeon Challenge — Part 8 | 1,160 | July 22, 2020, 12:05 p.m. |
| The T52 Sturgeon Challenge — Part 4 | 1,157 | July 21, 2020, 11:44 a.m. |
| The T52 Sturgeon Challenge — Part 3 | 1,158 | July 19, 2020, 4:58 a.m. |
| The T52 Sturgeon Challenge — Part 2 | 1,158 | July 15, 2020, 2:49 p.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,157 | July 15, 2020, 1:20 p.m. |
| Breaking a Filter Generator | 1,469 | Oct. 6, 2018, 7:29 a.m. |
| Autokey Cipher | 133 | Sept. 27, 2018, 6:41 p.m. |
| Summer Job | 1,327 | July 15, 2018, 5:49 a.m. |
| Trendy Messenger | 1,330 | July 13, 2018, 4:23 p.m. |
| Fastest in the West | 1,391 | July 1, 2018, 4:20 a.m. |
| Number Sequence — Part 10 | 102 | June 10, 2018, 5:55 a.m. |
| Flawed Usage of a OTP Cipher by the BND | 1,120 | April 1, 2018, 11:44 a.m. |
| New Year's Greetings — Part 4 | 100 | March 24, 2018, 4:28 p.m. |
| New Year's Greetings — Part 3 | 100 | March 24, 2018, 4:25 p.m. |
| New Year's Greetings — Part 2 | 100 | March 24, 2018, 4:22 p.m. |
| Handycipher — Part 6 | 13,925 | March 6, 2018, 2:54 p.m. |
| Handycipher — Part 5 | 13,926 | March 5, 2018, 11:40 a.m. |
| Handycipher — Part 4 | 13,928 | March 3, 2018, 3:12 a.m. |
| Weakened Handycipher — Part 6 | 1,136 | Feb. 18, 2018, 11:22 a.m. |
| Weakened Handycipher — Part 5 | 1,136 | Feb. 18, 2018, 11:18 a.m. |
| Weakened Handycipher — Part 4 | 1,137 | Feb. 12, 2018, 2:08 p.m. |
| The Einstein Enigma | 1,613 | Feb. 12, 2018, 3:48 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Feb. 4, 2018, 1:58 p.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,090 | Feb. 4, 2018, 8:07 a.m. |
| Handycipher — Part 3 | 13,640 | Jan. 31, 2018, 2:46 p.m. |
| Handycipher — Part 1 | 1,116 | Jan. 30, 2018, 5:42 a.m. |
| Handycipher — Part 2 | 1,116 | Jan. 30, 2018, 2:15 a.m. |
| Weakened Handycipher — Part 3 | 1,119 | Jan. 23, 2018, 2:27 a.m. |
| Weakened Handycipher — Part 2 | 1,119 | Jan. 22, 2018, 11:41 a.m. |
| Weakened Handycipher — Part 1 | 1,119 | Jan. 19, 2018, 2:26 a.m. |
| Weakened ElsieFour — Part 3 | 1,226 | Jan. 18, 2018, 1:49 a.m. |
| Advent-Challenge — Part 1 | 103 | Jan. 13, 2018, 11:16 a.m. |
| New Year's Greetings — Part 1 | 100 | Jan. 13, 2018, 9:49 a.m. |
| Advent Challenge — Part 4 | 1,433 | Jan. 4, 2018, 7:57 a.m. |
| Advent Challenge — Part 3 | 1,444 | Jan. 4, 2018, 7:56 a.m. |
| Advent-Challenge — Part 2 | 1,414 | Jan. 1, 2018, 12:24 p.m. |
| How do you become a big cryptographer? | 100 | Aug. 12, 2017, 3:27 a.m. |
| Kaskade-S/T — Part 3 | 1,095 | Feb. 17, 2017, 2:57 a.m. |
| M-138 — Part 3 | 1,127 | Feb. 7, 2017, 2:37 a.m. |
| Multilingual Monoalphabetic Substitution | 100 | Jan. 24, 2017, 5:27 p.m. |
| Weakened Granit — Part 1 | 100 | Jan. 18, 2017, 2:02 p.m. |
| ORYX Stream Cipher — Part 4a | 1,118 | Jan. 4, 2017, 9:11 a.m. |
| Smartcard RSA | 1,094 | Dec. 22, 2016, 9:04 p.m. |
| Sigaba Part 1 | 1,094 | Dec. 18, 2016, 1:40 a.m. |
| Image Noise | 100 | Dec. 8, 2016, 1:06 p.m. |
| Modified Caesar Cipher | 100 | Dec. 7, 2016, 3:23 p.m. |
| An 'unhearable' message | 100 | Dec. 3, 2016, 10:08 a.m. |
| An Invisible Message | 100 | Dec. 3, 2016, 9:43 a.m. |
| Double Column Transposition — Part 4 | 1,121 | Dec. 3, 2016, 6:47 a.m. |
| Purple 1 | 1,095 | Dec. 2, 2016, 6:42 a.m. |
| CMEA 2 | 13,305 | Nov. 27, 2016, 6:02 p.m. |
| CMEA 1 | 1,095 | Nov. 26, 2016, 5:53 p.m. |
| Keyshanc — Part 2 | 1,103 | Nov. 23, 2016, 10:34 a.m. |
| Music Code — Part 1 | 100 | Nov. 23, 2016, 3:29 a.m. |
| Music Code — Part 2 | 1,097 | Nov. 23, 2016, 3:03 a.m. |
| Pigpen with a twist — Part 2 | 1,099 | Nov. 22, 2016, 11:22 a.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,102 | Nov. 21, 2016, 2:27 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Nov. 21, 2016, 12:53 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,100 | Nov. 21, 2016, 4:58 a.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,100 | Nov. 20, 2016, 5:12 p.m. |
| Typex — Part 2 | 1,109 | Nov. 20, 2016, 10:59 a.m. |
| Typex — Part 1 | 1,108 | Nov. 19, 2016, 7:17 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,096 | Nov. 19, 2016, 4:46 a.m. |
| Unusual encryption using a diophantine equation | 1,099 | Nov. 18, 2016, 7:38 a.m. |
| Double Column Transposition — Part 1 | 1,120 | Nov. 12, 2016, 5:01 p.m. |
| Double Column Transposition — Part 3 | 1,121 | Nov. 12, 2016, 1:56 p.m. |
| Double Column Transposition — Part 2 | 1,121 | Nov. 12, 2016, 1:52 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,101 | Nov. 9, 2016, 4:33 p.m. |
| Unconcealed RSA messages | 1,100 | Nov. 8, 2016, 4:12 a.m. |
| A really long number sequence | 1,099 | Nov. 6, 2016, 8:30 a.m. |
| ORYX Stream Cipher — Part 3 (revised) | 1,111 | Nov. 4, 2016, 6:01 p.m. |
| Keyshanc — Part 1 | 1,103 | Nov. 4, 2016, 2:09 p.m. |
| ORYX Stream Cipher Part II | 1,095 | Nov. 1, 2016, 1:24 p.m. |
| Number Sequence — Part 4 | 100 | Oct. 30, 2016, 9:02 a.m. |
| Nils away on travel | 100 | Oct. 30, 2016, 8:59 a.m. |
| Number Sequence — Part 3 | 100 | Oct. 30, 2016, 8:18 a.m. |
| Recycled One-Time Pad | 100 | Oct. 29, 2016, 4:13 p.m. |
| Molehunt (Part 3/3) | 1,095 | Oct. 27, 2016, 4:26 p.m. |
| Kaskade-S/T — Part 2 | 1,097 | Oct. 27, 2016, 2:45 p.m. |
| Cascading Encryption — Part 1/3 | 100 | Oct. 24, 2016, 4:43 p.m. |
| Hill Cipher with Sudoku Key | 100 | Oct. 24, 2016, 11:59 a.m. |
| Turing Bombe Enigma I | 100 | Oct. 23, 2016, 10:15 a.m. |
| Enigma Messages | 100 | Oct. 22, 2016, 6:14 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Oct. 20, 2016, 11:10 a.m. |
| Partial Key Exposure with RSA — Part 1 | 1,102 | Oct. 18, 2016, 6:14 p.m. |
| BCR code (Book-Caesar-RSA) | 1,106 | Oct. 18, 2016, 2:46 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Oct. 17, 2016, 4:50 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | Oct. 17, 2016, 4:46 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Oct. 16, 2016, 3:08 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | Oct. 16, 2016, 2:58 p.m. |
| Enigma Part 1 | 1,095 | Oct. 16, 2016, 12:52 p.m. |
| Enigma Part 2 | 1,095 | Oct. 16, 2016, 11:47 a.m. |
| ADFGVX — Part 2 | 100 | Oct. 15, 2016, 1:34 p.m. |
| ADFGVX — Part 1 | 100 | Oct. 15, 2016, 12:52 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Oct. 15, 2016, 7:45 a.m. |
| ECDH-Key Exchange for Beginners | 100 | Oct. 15, 2016, 6:56 a.m. |
| Factorization Cipher — Part 3 | 1,101 | Oct. 14, 2016, 2:03 p.m. |
| Heartbleed — Part 3 | 1,127 | Oct. 13, 2016, 2:04 p.m. |
| Heartbleed — Part 2 | 100 | Oct. 13, 2016, 1:50 p.m. |
| M-138 — Part 2 | 1,133 | Oct. 13, 2016, 2:36 a.m. |
| Double Columnar Transposition | 100 | Oct. 12, 2016, 2:46 p.m. |
| Molehunt (Part 2/3) | 100 | Oct. 12, 2016, 1:55 p.m. |
| Heartbleed — Part 1 | 100 | Oct. 11, 2016, 2:31 p.m. |
| Molehunt (Part 1/3) | 100 | Oct. 11, 2016, 12:35 p.m. |
| ORYX Stream Cipher Part I | 1,095 | Oct. 10, 2016, 5:16 p.m. |
| Kaskade-S/T — Part 1 | 100 | Oct. 9, 2016, 6:02 a.m. |
| Pigpen with a twist — Part 1 | 100 | Oct. 8, 2016, 9:19 a.m. |
| Playfair with hints about the grid | 100 | Oct. 8, 2016, 7:14 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,095 | Oct. 8, 2016, 6:18 a.m. |
| ¿No Hablas Español? No problemo! | 100 | Oct. 7, 2016, 5:02 p.m. |
| Playfair Encryption | 100 | Oct. 7, 2016, 4:44 p.m. |
| Trifid Cipher | 100 | Oct. 7, 2016, 12:37 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Oct. 7, 2016, 11:57 a.m. |
| RSA: Two different keys — same ciphertext | 1,099 | Oct. 5, 2016, 5:35 p.m. |
| Factorization Cipher — Part 2 | 1,101 | Oct. 5, 2016, 5:25 p.m. |
| M-138 — Part 1 | 100 | Oct. 4, 2016, 1:27 p.m. |
| Hybrid Encryption I | 1,096 | Oct. 2, 2016, 9:25 a.m. |
| The Book Code: A Challenge for Bookworms | 100 | Oct. 1, 2016, 4:21 p.m. |
| Number Sequence — Part 8 | 100 | Oct. 1, 2016, 4:14 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,095 | Oct. 1, 2016, 7:14 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,099 | Sept. 29, 2016, 5:40 p.m. |
| Alice's Birthday Party (Part 2) | 1,095 | Sept. 29, 2016, 5:17 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Sept. 29, 2016, 1:39 p.m. |
| Alice's Birthday Party (Part 1) | 1,095 | Sept. 29, 2016, 1:26 p.m. |
| One-Time Pad with Flaws | 100 | Sept. 29, 2016, 12:57 p.m. |
| Monoalphabetic Substitution | 100 | Sept. 29, 2016, 12:53 p.m. |
| Number Sequence — Part 2 | 100 | Sept. 29, 2016, 11:51 a.m. |
| Number Sequence | 100 | Sept. 29, 2016, 11:50 a.m. |
| From Russia with Love | 100 | Sept. 29, 2016, 2:41 a.m. |
| Snow White and the seven dwarfs | 100 | Sept. 29, 2016, 2:39 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Sept. 29, 2016, 2:35 a.m. |
| Cracking SHA1-Hashed Passwords | 1,098 | Sept. 28, 2016, 7:02 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Sept. 28, 2016, 7 p.m. |
| Grille Cipher | 100 | Sept. 28, 2016, 6:57 p.m. |
| Factorization Cipher — Part 1 | 100 | Sept. 28, 2016, 6:56 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Sept. 28, 2016, 6:54 p.m. |
| Letter to the Templars — Part 3 | 1,107 | Sept. 28, 2016, 6:49 p.m. |
| Letter to the Templars — Part 2 | 100 | Sept. 28, 2016, 5:52 p.m. |
| A hidden word | 100 | Sept. 28, 2016, 5:46 p.m. |
| Letter to the Templars — Part 1 | 100 | Sept. 28, 2016, 5:43 p.m. |
| Beaver Code | 100 | Sept. 28, 2016, 5:33 p.m. |
| Caesar Encryption | 100 | Sept. 28, 2016, 5:31 p.m. |
| Original Caesar Cipher | 100 | Sept. 28, 2016, 5:21 p.m. |
Gold1
Silver3
Bronze2
