| The Hutton Cipher – Part 4 | 1,613 | Sept. 10, 2023, 11:07 p.m. |
| Polyphonic Substitution Cipher — Part 2 | 1,110 | July 26, 2023, 10:50 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 1,109 | July 26, 2023, 10:49 p.m. |
| The Hutton Cipher – Part 3 | 1,725 | July 23, 2023, 11:31 p.m. |
| The Josse Challenge – Part 3 | 1,222 | July 18, 2023, 8:25 a.m. |
| The Josse Challenge – Part 2 | 1,207 | July 18, 2023, 8:25 a.m. |
| The Josse Challenge – Part 1 | 1,201 | July 18, 2023, 8:25 a.m. |
| The Hutton Cipher – Part 2 | 1,367 | June 27, 2023, 6:28 p.m. |
| The Syllabary Cipher – Part 2 | 1,502 | Nov. 5, 2022, 9:02 p.m. |
| The Syllabary Cipher – Part 1 | 200 | Oct. 28, 2022, 3:59 p.m. |
| Merkle-Hellman Knapsack Challenge — Part 2 | 2,000 | Oct. 15, 2022, 2:34 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 200 | Oct. 15, 2022, 11:51 a.m. |
| Alberti Challenge — Part 1 | 200 | March 27, 2022, 1:25 p.m. |
| Wheatstone Cryptograph — Part 1 | 200 | April 21, 2021, 11:36 p.m. |
| Find the right route — Part 2 | 101 | April 2, 2021, 11:45 a.m. |
| Find the right route — Part 3 | 200 | Dec. 27, 2020, 3:51 p.m. |
| Find the right route — Part 1 | 200 | Oct. 27, 2020, 7:01 p.m. |
| The SZ42 Challenge — Part 4 | 1,725 | Sept. 1, 2020, 9:57 p.m. |
| The SZ42 Challenge — Part 3 | 1,725 | Aug. 17, 2020, 9:42 p.m. |
| The SZ42 Challenge — Part 2 | 2,000 | Aug. 5, 2020, 8:46 p.m. |
| The SZ42 Challenge — Part 1 | 2,000 | July 23, 2020, 7:34 p.m. |
| Lightweight Introduction to Lattices — Part 3 | 2,000 | July 17, 2020, 12:56 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 200 | June 24, 2020, 10 a.m. |
| Lightweight Introduction to Lattices — Part 1 | 200 | May 16, 2020, 8:32 p.m. |
| Polyhomophonic Substitution — Part 3 | 2,000 | April 6, 2020, 10:29 p.m. |
| Polyhomophonic Substitution — Part 2 | 2,000 | March 28, 2020, 10:07 p.m. |
| Polyhomophonic Substitution — Part 1 | 200 | March 22, 2020, 8:28 p.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 2,000 | Feb. 20, 2020, 8:27 p.m. |
| Cipher ID — Part 1 | 2,000 | Nov. 20, 2019, 10:40 a.m. |
| A Cloaked Substitution Cipher — Part 2 | 1,523 | Sept. 2, 2019, 6:56 p.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,576 | Aug. 26, 2019, 4:24 p.m. |
| Handycipher made in love — Part 2 | 2,000 | May 21, 2019, 7:53 p.m. |
| Homophonic Encryption — Part 2 | 1,725 | May 10, 2019, 10:04 p.m. |
| Homophonic Encryption — Part 4 | 2,000 | May 9, 2019, 5:58 p.m. |
| Homophonic Encryption — Part 3 | 2,000 | May 9, 2019, 5:34 p.m. |
| Homophonic Encryption — Part 1 | 2,000 | May 4, 2019, 11:35 p.m. |
| Handycipher made in love — Part 1 | 2,000 | Feb. 16, 2019, 2:52 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 2,000 | Feb. 16, 2019, 1:26 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 200 | Jan. 9, 2019, 3:41 p.m. |
| "The Road" — Part 1 | 1,824 | Dec. 10, 2018, 3:47 p.m. |
| RSA Factoring Challenge: RSA-230 | 0 | Nov. 7, 2018, 9:12 p.m. |
| Cryptanalysis Hacking Puzzles — Part 1 | 117 | Nov. 1, 2018, 7:25 p.m. |
| Modular Sequences | 200 | Sept. 26, 2018, 9:53 a.m. |
| Autokey Cipher | 200 | Sept. 26, 2018, 9:50 a.m. |
| Fastest in the West | 1,398 | June 29, 2018, 3:27 p.m. |
| Trendy Messenger | 1,398 | June 29, 2018, 2:25 p.m. |
| Summer Job | 1,406 | June 28, 2018, 8:33 p.m. |
| Number Sequence — Part 10 | 200 | April 18, 2018, 6:25 p.m. |
| The Einstein Enigma | 1,613 | Feb. 12, 2018, 12:55 a.m. |
| Advent Challenge — Part 4 | 1,725 | Dec. 23, 2017, 11:50 p.m. |
| Advent Challenge — Part 3 | 1,824 | Dec. 23, 2017, 9:23 p.m. |
| Advent-Challenge — Part 2 | 1,824 | Dec. 17, 2017, 11:35 p.m. |
| AES ECB Wrong Encoding | 1,824 | Dec. 17, 2017, 11:34 p.m. |
| Advent-Challenge — Part 1 | 150 | Dec. 10, 2017, 4:51 p.m. |
| Number Sequence — Part 9 | 200 | Nov. 17, 2017, 12:08 a.m. |
| Kaskade-S/T — Part 6 (RansomKaskade Part 1) | 1,444 | July 14, 2017, 2 p.m. |
| M-138 — Part 4 | 1,122 | June 6, 2017, 9:20 p.m. |
| Holographic Encryption — Part 2 | 1,444 | April 20, 2017, 5:54 p.m. |
| Holographic Encryption — Part 1 | 1,456 | April 19, 2017, 5:59 p.m. |
| New Year's Greetings — Part 5 | 1,199 | Aug. 30, 2016, 10:10 p.m. |
| ASAC — A Strong(er) ADFGVX Cipher — Part 1 | 2,000 | July 9, 2016, 8:51 p.m. |
| New Year's Greetings — Part 4 | 200 | March 22, 2016, 1:17 a.m. |
| New Year's Greetings — Part 3 | 200 | March 22, 2016, 1:17 a.m. |
| New Year's Greetings — Part 2 | 200 | March 22, 2016, 1:16 a.m. |
| New Year's Greetings — Part 1 | 200 | March 22, 2016, 1:16 a.m. |
| Image Noise | 200 | Nov. 20, 2015, 9:33 p.m. |
| News from Castle Mansfeld | 200 | Nov. 13, 2015, 10:41 p.m. |
| Sigaba Part 1 | 1,100 | Oct. 14, 2015, 1:58 p.m. |
| Weakened Granit — Part 1 | 200 | Sept. 24, 2015, 12:32 p.m. |
| Number Sequence — Part 8 | 133 | Sept. 16, 2015, 9:15 a.m. |
| Flawed Usage of a OTP Cipher by the BND | 1,725 | Aug. 26, 2015, 5:13 p.m. |
| Cascading Encryption — Part 3/3 | 1,125 | June 17, 2015, 12:20 p.m. |
| Weakened Handycipher — Part 1 | 1,485 | May 22, 2015, 7:32 p.m. |
| Weakened Handycipher — Part 2 | 1,523 | May 21, 2015, 1:33 a.m. |
| Weakened Handycipher — Part 3 | 1,576 | May 18, 2015, 2:55 p.m. |
| A hidden word — Part 2 | 200 | April 16, 2015, 6:35 p.m. |
| Number Sequence — Part 7 | 200 | March 23, 2015, 4:33 p.m. |
| Number Sequence — Part 6 | 200 | March 23, 2015, 2 p.m. |
| M-138 — Part 3 | 1,725 | Dec. 26, 2014, 9:24 p.m. |
| M-138 — Part 2 | 1,824 | Dec. 25, 2014, 2 a.m. |
| M-138 — Part 1 | 200 | Dec. 24, 2014, 4:21 p.m. |
| The Last Note | 200 | Sept. 23, 2014, 12:22 a.m. |
| Heartbleed — Part 2 | 120 | Sept. 1, 2014, 8:09 p.m. |
| Heartbleed — Part 1 | 125 | Sept. 1, 2014, 10:40 a.m. |
| Double Column Transposition — Part 4 | 2,000 | May 20, 2014, 1:54 a.m. |
| Double Column Transposition — Part 2 | 1,660 | May 6, 2014, 11:29 a.m. |
| Double Column Transposition — Part 3 | 1,660 | May 6, 2014, 11:23 a.m. |
| ORYX Stream Cipher — Part 4a | 1,433 | April 28, 2014, 8:48 a.m. |
| Double Column Transposition — Part 1 | 2,000 | April 5, 2014, 1:37 a.m. |
| Spanish Strip Cipher — Part 2 | 1,824 | March 29, 2014, 1:03 p.m. |
| Spanish Strip Cipher — Part 1 | 1,824 | March 28, 2014, 3:55 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 200 | March 5, 2014, 6:39 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 200 | March 5, 2014, 5:31 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 200 | March 5, 2014, 5:28 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | Dec. 1, 2013, 6:31 p.m. |
| Trifid Cipher | 200 | Oct. 29, 2013, 12:11 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 200 | Oct. 28, 2013, 11:12 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 200 | Sept. 26, 2013, 3:14 p.m. |
| Hill Cipher with Sudoku Key | 200 | Sept. 4, 2013, 4:45 p.m. |
| From Russia with Love | 200 | Sept. 4, 2013, 2:45 p.m. |
| Nils away on travel | 200 | Aug. 8, 2013, 1:22 p.m. |
| Pigpen with a twist — Part 3 | 1,131 | July 31, 2013, 7:07 p.m. |
| Cascading Encryption — Part 2/3 | 1,214 | July 31, 2013, 7:03 p.m. |
| RSA Factoring Challenge: RSA-704 | 0 | July 31, 2013, 6:55 p.m. |
| ORYX Stream Cipher — Part 3 (revised) | 2,000 | June 7, 2013, 8:33 p.m. |
| Snow White and the seven dwarfs | 200 | April 20, 2013, 3:45 p.m. |
| Typex — Part 2 | 1,576 | April 9, 2013, 1:57 p.m. |
| Reserve Hand Procedure — Part 1 | 200 | March 7, 2013, 7:05 p.m. |
| Typex — Part 1 | 2,000 | Feb. 28, 2013, 11:48 p.m. |
| Notes of an Italian Soldier | 3,000 | Feb. 18, 2013, 7:59 p.m. |
| Multilingual Monoalphabetic Substitution | 200 | Jan. 30, 2013, 9:36 p.m. |
| Cascading Encryption — Part 1/3 | 200 | Jan. 26, 2013, 11:18 a.m. |
| Enigma Messages | 200 | Jan. 23, 2013, 10:01 p.m. |
| Playfair with hints about the grid | 200 | Jan. 16, 2013, 7 p.m. |
| A hidden word | 200 | Jan. 6, 2013, 4:15 p.m. |
| Strange Message from Thessaloniki | 200 | Dec. 10, 2012, 9:35 p.m. |
| Recycled One-Time Pad | 113 | Nov. 27, 2012, 11:55 p.m. |
| Letter to the Templars — Part 3 | 2,000 | Oct. 9, 2012, 6:08 p.m. |
| BCR code (Book-Caesar-RSA) | 2,000 | Sept. 12, 2012, 10:42 p.m. |
| Ku Klux Klan | 1,000 | Aug. 28, 2012, 12:35 a.m. |
| Zodiac Cipher | 100 | Aug. 26, 2012, 7:40 p.m. |
| Kaskade-S/T — Part 5 | 1,145 | Aug. 26, 2012, 7:39 p.m. |
| Beaver Code | 200 | Aug. 13, 2012, 9:47 p.m. |
| Letter to the Templars — Part 2 | 200 | July 30, 2012, 9:51 p.m. |
| Letter to the Templars — Part 1 | 200 | July 17, 2012, 8:54 p.m. |
| An 'unhearable' message | 200 | June 5, 2012, 10:45 p.m. |
| How do you become a big cryptographer? | 200 | May 28, 2012, 8:05 p.m. |
| Keyshanc — Part 2 | 2,000 | May 21, 2012, 11:46 p.m. |
| Keyshanc — Part 1 | 2,000 | May 21, 2012, 11:10 p.m. |
| Concealed Messages — Vigenère's Night Sky | 1,807 | May 5, 2012, 6:20 p.m. |
| Number Sequence — Part 4 | 114 | April 24, 2012, 8:13 p.m. |
| Number Sequence — Part 5 | 114 | April 24, 2012, 8:13 p.m. |
| ¿No Hablas Español? No problemo! | 200 | April 19, 2012, 9:04 a.m. |
| Number Sequence — Part 3 | 200 | March 31, 2012, 9:40 a.m. |
| The Book Code: A Challenge for Bookworms | 200 | March 21, 2012, 6:35 p.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 2,000 | March 10, 2012, 9:16 p.m. |
| ECDH-Key Exchange for Beginners | 200 | Feb. 24, 2012, 8:50 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 101 | Feb. 11, 2012, 4:28 p.m. |
| Partial Key Exposure with RSA — Part 1 | 2,000 | Feb. 11, 2012, 4:11 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 2,000 | Jan. 16, 2012, 11:02 p.m. |
| Factorization Cipher — Part 3 | 1,824 | Jan. 7, 2012, 10:35 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 200 | Dec. 21, 2011, 11:01 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,824 | Dec. 8, 2011, 9:48 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 2,000 | Dec. 8, 2011, 2:37 p.m. |
| Factorization Cipher — Part 2 | 2,000 | Dec. 2, 2011, 12:04 p.m. |
| Music Code — Part 1 | 101 | Nov. 19, 2011, 11:29 p.m. |
| Music Code — Part 2 | 1,191 | Nov. 19, 2011, 11:27 p.m. |
| Unconcealed RSA messages | 2,000 | Nov. 2, 2011, 4:49 p.m. |
| An Invisible Message | 150 | Oct. 18, 2011, 7:36 p.m. |
| Turing Bombe Enigma I | 150 | Oct. 18, 2011, 7:36 p.m. |
| Factorization Cipher — Part 1 | 150 | Oct. 18, 2011, 7:35 p.m. |
| Grille Cipher | 200 | Oct. 14, 2011, 9:10 p.m. |
| Double Columnar Transposition | 200 | Oct. 12, 2011, 9:40 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 200 | Sept. 9, 2011, 1:13 p.m. |
| Pigpen with a twist — Part 2 | 1,576 | Sept. 7, 2011, 7:46 p.m. |
| A really long number sequence | 2,000 | Sept. 6, 2011, 2:07 p.m. |
| Pigpen with a twist — Part 1 | 200 | Sept. 5, 2011, 10:17 p.m. |
| Modified Caesar Cipher | 200 | Sept. 3, 2011, 9:48 a.m. |
| Unusual encryption using a diophantine equation | 2,000 | Sept. 2, 2011, 11:05 p.m. |
| ADFGVX — Part 2 | 200 | Aug. 16, 2011, 2:24 p.m. |
| ADFGVX — Part 1 | 200 | Aug. 16, 2011, 2:23 p.m. |
| RSA: Two different keys — same ciphertext | 2,000 | Aug. 15, 2011, 7:49 p.m. |
| RSA with Special d | 14,348 | Aug. 8, 2011, 8:17 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,725 | July 25, 2011, 7:41 p.m. |
| Number Sequence — Part 2 | 200 | July 11, 2011, 6:06 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 200 | April 7, 2011, 6:43 p.m. |
| Cracking SHA1-Hashed Passwords | 2,000 | April 4, 2011, 11:40 p.m. |
| Lattice Part 1 | 1,576 | March 16, 2011, 2:20 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,206 | March 8, 2011, 10:23 p.m. |
| Kaskade-S/T — Part 2 | 1,613 | March 8, 2011, 6:26 p.m. |
| Kaskade-S/T — Part 1 | 120 | March 8, 2011, 1:04 p.m. |
| Kaskade-S/T — Part 3 | 1,613 | March 8, 2011, 11:25 a.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,216 | Feb. 14, 2011, 4:01 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 2,000 | Jan. 14, 2011, 6:58 p.m. |
| Playfair Encryption | 113 | Dec. 29, 2010, 7:12 p.m. |
| Original Caesar Cipher | 200 | Dec. 15, 2010, 8:38 a.m. |
| CMEA 2 | 17,412 | Dec. 14, 2010, 5 p.m. |
| CMEA 1 | 1,613 | Dec. 10, 2010, 3:02 p.m. |
| Akelarre Part 1 | 1,523 | Dec. 2, 2010, 2:39 p.m. |
| Enigma Part 2 | 1,307 | Nov. 22, 2010, 9:09 p.m. |
| Smartcard RSA | 1,344 | Nov. 21, 2010, 6:56 p.m. |
| Enigma Combinatorics | 200 | Nov. 13, 2010, 12:16 a.m. |
| One-Time Pad with Flaws | 200 | Nov. 12, 2010, 11:20 p.m. |
| Hybrid Encryption I | 1,502 | Nov. 10, 2010, 8:39 a.m. |
| ORYX Stream Cipher Part II | 1,353 | Nov. 8, 2010, 2:54 p.m. |
| ORYX Stream Cipher Part I | 1,367 | Nov. 5, 2010, 11:22 p.m. |
| Molehunt (Part 3/3) | 1,444 | Nov. 5, 2010, 11:43 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,378 | Nov. 3, 2010, 6:07 p.m. |
| A Secret Message from Castle Mansfeld | 107 | Oct. 29, 2010, 11:32 a.m. |
| Enigma Part 1 | 1,423 | Oct. 28, 2010, 9:54 p.m. |
| Classical Ciphers^3 | 107 | Oct. 28, 2010, 11:04 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 114 | Oct. 28, 2010, 10:52 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 114 | Oct. 28, 2010, 10:50 a.m. |
| Caesar Encryption | 114 | Oct. 28, 2010, 9:54 a.m. |
| Monoalphabetic Substitution | 107 | Oct. 27, 2010, 11:44 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 107 | Oct. 27, 2010, 11:26 p.m. |
| Alice's Birthday Party (Part 2) | 1,433 | Oct. 27, 2010, 10:59 p.m. |
| Alice's Birthday Party (Part 1) | 1,433 | Oct. 27, 2010, 10:56 p.m. |
| Molehunt (Part 2/3) | 120 | Oct. 27, 2010, 10:45 p.m. |
| Molehunt (Part 1/3) | 120 | Oct. 27, 2010, 9:41 p.m. |
| Number Sequence | 107 | Oct. 27, 2010, 9:40 p.m. |
Gold39
Silver39
Bronze24
