| The Hutton Cipher – Part 1 | 1,660 | May 6, 2023, 8:58 a.m. |
| The Josse Challenge – Part 3 | 1,725 | March 29, 2023, 6:08 p.m. |
| Spirale — Part 3 | 1,089 | March 27, 2023, 12:04 a.m. |
| Spirale — Part 1 | 1,089 | March 11, 2023, 12:56 a.m. |
| Spirale — Part 2 | 1,089 | March 10, 2023, 11:02 p.m. |
| The Josse Challenge – Part 2 | 1,824 | Feb. 26, 2023, 7:42 p.m. |
| The Josse Challenge – Part 1 | 1,444 | Feb. 22, 2023, 8:07 p.m. |
| Polyhomophonic Substitution — Part 3 | 1,117 | Jan. 27, 2023, 6:42 p.m. |
| Flawed Usage of a OTP Cipher by the BND | 1,090 | Dec. 14, 2022, 1:11 a.m. |
| ASAC — A Strong(er) ADFGVX Cipher — Part 1 | 1,093 | Dec. 10, 2022, 12:34 a.m. |
| Hill Cipher | 1,235 | Dec. 7, 2022, 9:24 p.m. |
| The Syllabary Cipher – Part 4 | 1,324 | Nov. 30, 2022, 7:56 p.m. |
| The Syllabary Cipher – Part 5 | 1,327 | Nov. 29, 2022, 9:36 p.m. |
| The Syllabary Cipher – Part 3 | 1,327 | Nov. 29, 2022, 3:07 p.m. |
| The Heavy T52 Sturgeon Challenge — Part 5 | 13,697 | Nov. 28, 2022, 12:01 a.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,079 | Nov. 23, 2022, 10:34 p.m. |
| Merkle-Hellman Knapsack Challenge — Part 2 | 1,353 | Nov. 8, 2022, 5:34 p.m. |
| Lattice Part 1 | 1,079 | Nov. 7, 2022, 9:05 p.m. |
| The Syllabary Cipher – Part 2 | 1,523 | Nov. 5, 2022, 3:52 a.m. |
| The Syllabary Cipher – Part 1 | 200 | Oct. 28, 2022, 2:34 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 150 | Oct. 15, 2022, 9:21 p.m. |
| The Heavy T52 Sturgeon Challenge — Part 7 | 13,745 | Sept. 6, 2022, 1:45 a.m. |
| The T52 Sturgeon Challenge — Part 10 | 1,115 | Aug. 31, 2022, 7:26 p.m. |
| The T52 Sturgeon Challenge — Part 12 | 1,115 | Aug. 22, 2022, 6:35 p.m. |
| The T52 Sturgeon Challenge — Part 4 | 1,115 | July 20, 2022, 2:40 a.m. |
| The T52 Sturgeon Challenge — Part 9 | 1,116 | June 28, 2022, 5:41 p.m. |
| Alberti Challenge — Part 2 | 1,385 | June 2, 2022, 7:43 p.m. |
| Spanish Strip Cipher — Part 2 | 1,087 | May 29, 2022, 4:03 p.m. |
| AES ECB Wrong Encoding | 1,104 | May 14, 2022, 11:35 p.m. |
| The T52 Sturgeon Challenge — Part 11 | 1,118 | May 12, 2022, 11:20 p.m. |
| Polyhomophonic Substitution — Part 2 | 1,129 | April 7, 2022, 8 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,080 | April 3, 2022, 6:52 p.m. |
| Alberti Challenge — Part 1 | 200 | March 27, 2022, 12:24 a.m. |
| Factorization Cipher — Part 3 | 1,082 | March 26, 2022, 2:11 a.m. |
| Cascading Encryption — Part 2/3 | 1,085 | March 18, 2022, 5:34 p.m. |
| The SZ42 Challenge — Part 3 | 1,138 | March 16, 2022, 8:14 p.m. |
| The T52 Sturgeon Challenge — Part 8 | 1,120 | March 2, 2022, 11:08 p.m. |
| Modified Vigenère Cipher | 1,349 | Feb. 20, 2022, 1:08 a.m. |
| Wheatstone Cryptograph — Part 2 | 1,182 | Dec. 29, 2021, 1:54 p.m. |
| The SZ42 Challenge — Part 13 | 1,725 | Oct. 8, 2021, 11:29 p.m. |
| The SZ42 Challenge — Part 12 | 1,725 | Oct. 8, 2021, 8:26 p.m. |
| The SZ42 Challenge — Part 2 | 1,151 | Sept. 30, 2021, 12:09 a.m. |
| The SZ42 Challenge — Part 1 | 1,152 | Sept. 5, 2021, 5:54 p.m. |
| The SZ42 Challenge — Part 9 | 1,178 | Aug. 16, 2021, 2:18 a.m. |
| The SZ42 Challenge — Part 6 | 1,167 | July 28, 2021, 9:08 p.m. |
| The SZ42 Challenge — Part 7 | 1,173 | July 18, 2021, 3:54 p.m. |
| The SZ42 Challenge — Part 5 | 1,164 | July 17, 2021, 12:04 a.m. |
| The SZ42 Challenge — Part 4 | 1,163 | July 16, 2021, 10:52 a.m. |
| The SZ42 Challenge — Part 8 | 1,174 | July 15, 2021, 5:11 a.m. |
| The T52 Sturgeon Challenge — Part 3 | 1,130 | June 30, 2021, 11:28 a.m. |
| The T52 Sturgeon Challenge — Part 2 | 1,131 | June 20, 2021, 2:04 p.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,130 | June 15, 2021, 11:06 p.m. |
| Wheatstone Cryptograph — Part 1 | 150 | April 23, 2021, 12:31 a.m. |
| M-138 — Part 4 | 1,094 | March 21, 2021, 11:21 p.m. |
| Find the right route — Part 3 | 107 | Jan. 8, 2021, 7:40 p.m. |
| Find the right route — Part 2 | 106 | Jan. 3, 2021, 8:42 p.m. |
| Find the right route — Part 1 | 104 | Nov. 21, 2020, 10:35 p.m. |
| Modular Sequences | 100 | Oct. 20, 2020, 4:35 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 101 | Aug. 29, 2020, 9:12 p.m. |
| Lightweight Introduction to Lattices — Part 3 | 1,824 | July 17, 2020, 7:54 p.m. |
| Lightweight Introduction to Lattices — Part 1 | 117 | May 21, 2020, 10:11 p.m. |
| Polyhomophonic Substitution — Part 1 | 107 | April 5, 2020, 4:16 p.m. |
| RSA Factoring Challenge: RSA-232 | 0 | March 12, 2020, 9:24 p.m. |
| RSA Factoring Challenge: RSA-250 | 0 | March 12, 2020, 9:20 p.m. |
| Polyphonic Substitution Cipher — Part 2 | 1,284 | March 4, 2020, 9:43 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 1,229 | March 1, 2020, 8:01 p.m. |
| Cipher ID — Part 1 | 1,252 | Feb. 2, 2020, 8:21 a.m. |
| RSA Factoring Challenge: RSA-240 | 0 | Dec. 15, 2019, 10:40 p.m. |
| Homophonic Encryption — Part 4 | 1,196 | Oct. 27, 2019, 8 p.m. |
| A Cloaked Substitution Cipher — Part 2 | 1,576 | Aug. 31, 2019, 12:32 a.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,660 | Aug. 24, 2019, 7:27 p.m. |
| Homophonic Encryption — Part 3 | 1,310 | June 15, 2019, 11:35 p.m. |
| Spanish Strip Cipher — Part 1 | 1,099 | June 11, 2019, 9:41 p.m. |
| Handycipher made in love — Part 2 | 1,725 | May 23, 2019, 11 p.m. |
| Homophonic Encryption — Part 2 | 1,469 | May 19, 2019, 4:12 p.m. |
| Homophonic Encryption — Part 1 | 1,824 | May 5, 2019, 7:47 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 133 | Jan. 11, 2019, 6:10 p.m. |
| Number Sequence — Part 9 | 100 | Jan. 9, 2019, 7:20 p.m. |
| Image Noise | 100 | Jan. 7, 2019, 6:24 p.m. |
| News from Castle Mansfeld | 100 | Dec. 24, 2018, 1:35 p.m. |
| Strange Message from Thessaloniki | 100 | Dec. 20, 2018, 7:45 p.m. |
| RSA Factoring Challenge: RSA-230 | 0 | Nov. 7, 2018, 6:49 p.m. |
| Weakened ElsieFour — Part 1 | 1,200 | Oct. 6, 2018, 8:53 p.m. |
| Autokey Cipher | 120 | Sept. 29, 2018, 5:44 p.m. |
| Advent Challenge — Part 3 | 1,190 | July 2, 2018, 10:33 p.m. |
| Trendy Messenger | 1,523 | June 19, 2018, 7:26 p.m. |
| Summer Job | 1,613 | June 17, 2018, 11:54 a.m. |
| Fastest in the West | 1,660 | June 15, 2018, 8:11 p.m. |
| Number Sequence — Part 10 | 103 | May 27, 2018, 5:04 p.m. |
| Number Sequence — Part 6 | 100 | April 6, 2018, 10:51 a.m. |
| The Einstein Enigma | 1,613 | Feb. 12, 2018, 8:34 p.m. |
| Advent Challenge — Part 4 | 1,302 | Jan. 31, 2018, 6:24 p.m. |
| Advent-Challenge — Part 2 | 1,469 | Dec. 26, 2017, 8:17 p.m. |
| Advent-Challenge — Part 1 | 107 | Dec. 22, 2017, 6:26 p.m. |
| RSA Factoring Challenge: RSA-220 | 0 | July 22, 2017, 1:24 p.m. |
| New Year's Greetings — Part 4 | 100 | Oct. 10, 2016, 8:39 p.m. |
| New Year's Greetings — Part 3 | 100 | Oct. 9, 2016, 6:21 p.m. |
| New Year's Greetings — Part 2 | 100 | Oct. 9, 2016, 4:36 p.m. |
| New Year's Greetings — Part 1 | 101 | Sept. 29, 2016, 4:46 p.m. |
| Weakened Granit — Part 1 | 104 | Oct. 19, 2015, 8:53 a.m. |
| Number Sequence — Part 7 | 102 | May 7, 2015, 4:55 p.m. |
| M-138 — Part 3 | 1,613 | Dec. 28, 2014, 10:36 p.m. |
| Purple 1 | 1,105 | Dec. 27, 2014, 9:52 a.m. |
| M-138 — Part 2 | 1,824 | Dec. 25, 2014, 2:43 a.m. |
| M-138 — Part 1 | 200 | Dec. 24, 2014, 8:37 p.m. |
| An 'unhearable' message | 100 | Dec. 17, 2014, 9:25 p.m. |
| An Invisible Message | 100 | Nov. 18, 2014, 4:59 p.m. |
| Double Column Transposition — Part 5 | 1,211 | Nov. 5, 2014, 1:45 p.m. |
| Double Column Transposition — Part 1 | 1,185 | Nov. 1, 2014, 10:52 a.m. |
| Heartbleed — Part 2 | 103 | Oct. 5, 2014, 9:32 a.m. |
| Heartbleed — Part 1 | 103 | Oct. 4, 2014, 8:38 p.m. |
| The Last Note | 111 | Sept. 30, 2014, 11:05 p.m. |
| Double Column Transposition — Part 4 | 1,305 | June 29, 2014, 11:55 a.m. |
| Double Column Transposition — Part 3 | 1,283 | June 22, 2014, 7:35 p.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,125 | June 9, 2014, 4:23 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,121 | June 7, 2014, 9:16 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,121 | June 6, 2014, 10:15 p.m. |
| Double Column Transposition — Part 2 | 1,660 | May 5, 2014, 8:22 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 125 | March 9, 2014, 8:56 a.m. |
| Enigma Messages with Repeated Letters — Part 3 | 133 | March 8, 2014, 10:06 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 200 | March 5, 2014, 9:01 p.m. |
| RSA with Special d | 13,568 | Feb. 27, 2014, 5:15 p.m. |
| Unusual encryption using a diophantine equation | 1,122 | Feb. 5, 2014, 8:13 p.m. |
| Ku Klux Klan | 1,050 | Jan. 21, 2014, 3:05 a.m. |
| Keyshanc — Part 2 | 1,136 | Jan. 19, 2014, 2:12 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Dec. 29, 2013, 7:41 p.m. |
| CMEA 2 | 13,616 | Dec. 27, 2013, 9:39 p.m. |
| A really long number sequence | 1,124 | Dec. 21, 2013, 11:58 a.m. |
| Smartcard RSA | 1,114 | Dec. 7, 2013, 1:03 p.m. |
| CMEA 1 | 1,115 | Dec. 6, 2013, 11:51 a.m. |
| RSA Factoring Challenge: RSA-210 | 0 | Dec. 2, 2013, 6:54 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Nov. 29, 2013, 12:02 a.m. |
| RSA Factoring Challenge: RSA-704 | 0 | Nov. 24, 2013, 9 a.m. |
| Pigpen with a twist — Part 3 | 1,126 | Nov. 10, 2013, 12:45 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 108 | Nov. 9, 2013, 11:09 p.m. |
| Zodiac Cipher | 100 | Nov. 2, 2013, 10:39 a.m. |
| Trifid Cipher | 120 | Nov. 1, 2013, 11:38 p.m. |
| Pigpen with a twist — Part 2 | 1,126 | Oct. 28, 2013, 11:38 a.m. |
| Music Code — Part 2 | 1,122 | Oct. 20, 2013, 9:36 p.m. |
| Playfair Encryption | 100 | Oct. 6, 2013, 9:02 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 200 | Sept. 26, 2013, 8:04 p.m. |
| Music Code — Part 1 | 100 | Sept. 9, 2013, 8:29 p.m. |
| From Russia with Love | 200 | Sept. 4, 2013, 7:36 p.m. |
| Hill Cipher with Sudoku Key | 200 | Sept. 4, 2013, 6:43 p.m. |
| Nils away on travel | 200 | Aug. 8, 2013, 9:19 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,117 | Aug. 7, 2013, 7:30 p.m. |
| Unconcealed RSA messages | 1,137 | June 17, 2013, 10:16 p.m. |
| ORYX Stream Cipher — Part 3 (revised) | 2,000 | June 7, 2013, 5:16 a.m. |
| Typex — Part 1 | 1,256 | May 10, 2013, 6:12 a.m. |
| Typex — Part 2 | 1,362 | April 27, 2013, 11:56 a.m. |
| Snow White and the seven dwarfs | 120 | April 24, 2013, 10:39 p.m. |
| Cascading Encryption — Part 1/3 | 101 | April 10, 2013, 3:05 p.m. |
| Enigma Part 2 | 1,122 | April 4, 2013, 8:40 p.m. |
| Enigma Part 1 | 1,122 | March 15, 2013, 2:30 p.m. |
| ORYX Stream Cipher Part II | 1,123 | March 12, 2013, 12:17 a.m. |
| Reserve Hand Procedure — Part 1 | 200 | March 7, 2013, 12:02 p.m. |
| How do you become a big cryptographer? | 100 | Feb. 25, 2013, 8:35 p.m. |
| ORYX Stream Cipher Part I | 1,125 | Jan. 20, 2013, 1:55 p.m. |
| Number Sequence — Part 5 | 100 | Jan. 10, 2013, 8:01 a.m. |
| Molehunt (Part 3/3) | 1,127 | Dec. 2, 2012, 8:32 p.m. |
| Recycled One-Time Pad | 109 | Nov. 30, 2012, 8:34 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Nov. 27, 2012, 5:29 p.m. |
| Monoalphabetic Substitution | 100 | Nov. 19, 2012, 1:38 p.m. |
| Cracking SHA1-Hashed Passwords | 1,138 | Nov. 6, 2012, 8:37 a.m. |
| Kaskade-S/T — Part 3 | 1,136 | Nov. 3, 2012, 10:55 p.m. |
| Factorization Cipher — Part 2 | 1,161 | Oct. 30, 2012, 3:43 a.m. |
| Letter to the Templars — Part 3 | 2,000 | Oct. 10, 2012, 2:15 p.m. |
| Enigma Combinatorics | 100 | Sept. 11, 2012, 7:54 a.m. |
| ¿No Hablas Español? No problemo! | 101 | Sept. 10, 2012, 4:22 p.m. |
| The Book Code: A Challenge for Bookworms | 101 | Aug. 30, 2012, 5:35 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,187 | Aug. 30, 2012, 8:15 a.m. |
| Kaskade-S/T — Part 2 | 1,141 | Aug. 24, 2012, 7:51 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,184 | Aug. 16, 2012, 6:40 p.m. |
| Beaver Code | 200 | Aug. 13, 2012, 11:38 p.m. |
| Letter to the Templars — Part 2 | 200 | July 30, 2012, 9:47 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,133 | July 29, 2012, 6:07 p.m. |
| Keyshanc — Part 1 | 1,259 | July 29, 2012, 4:49 p.m. |
| Letter to the Templars — Part 1 | 150 | July 18, 2012, 12:55 a.m. |
| Kaskade-S/T — Part 1 | 100 | July 4, 2012, 4:58 p.m. |
| Hybrid Encryption I | 1,136 | June 29, 2012, 7:10 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,163 | June 10, 2012, 11:32 p.m. |
| Alice's Birthday Party (Part 1) | 1,137 | May 31, 2012, 8:41 a.m. |
| Alice's Birthday Party (Part 2) | 1,137 | May 31, 2012, 12:24 a.m. |
| Modified Caesar Cipher | 100 | May 25, 2012, 7:40 p.m. |
| Classical Ciphers^3 | 100 | May 22, 2012, 11:42 a.m. |
| RSA: Two different keys — same ciphertext | 1,173 | May 5, 2012, 7:18 p.m. |
| Number Sequence — Part 4 | 113 | April 26, 2012, 1:31 p.m. |
| Turing Bombe Enigma I | 101 | April 23, 2012, 6:16 p.m. |
| Factorization Cipher — Part 1 | 101 | April 22, 2012, 6:36 p.m. |
| ECDH-Key Exchange for Beginners | 102 | April 16, 2012, 11:44 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | April 16, 2012, 11 p.m. |
| Molehunt (Part 1/3) | 100 | April 11, 2012, 12:50 p.m. |
| Molehunt (Part 2/3) | 100 | April 11, 2012, 11:05 a.m. |
| Number Sequence — Part 3 | 125 | April 3, 2012, 2:12 p.m. |
| Double Columnar Transposition | 101 | March 21, 2012, 7:51 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | March 15, 2012, 2:41 p.m. |
| One-Time Pad with Flaws | 100 | March 13, 2012, 7:50 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | March 10, 2012, 9:15 a.m. |
| ADFGVX — Part 1 | 100 | March 7, 2012, 1:20 p.m. |
| Pigpen with a twist — Part 1 | 101 | March 6, 2012, 12:33 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Feb. 25, 2012, 4:57 p.m. |
| ADFGVX — Part 2 | 101 | Feb. 20, 2012, 11:04 a.m. |
| Grille Cipher | 101 | Feb. 1, 2012, 9:56 p.m. |
| Caesar Encryption | 100 | Jan. 19, 2012, 4:30 p.m. |
| Number Sequence — Part 2 | 101 | Jan. 14, 2012, 2:03 p.m. |
| Number Sequence | 100 | Jan. 14, 2012, 12:49 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 101 | Jan. 12, 2012, 7:27 p.m. |
| Original Caesar Cipher | 100 | Dec. 22, 2011, 3:34 p.m. |
Gold3
Silver2
Bronze5
