| The Syllabary Cipher – Part 3 | 2,000 | Oct. 28, 2022, 5:57 p.m. |
| The Syllabary Cipher – Part 2 | 2,000 | Oct. 28, 2022, 5:35 p.m. |
| The Syllabary Cipher – Part 1 | 200 | Oct. 28, 2022, 5:31 p.m. |
| Hill Cipher | 1,281 | Oct. 26, 2022, 8:50 p.m. |
| Merkle-Hellman Knapsack Challenge — Part 2 | 2,000 | Oct. 15, 2022, 12:39 a.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 200 | Oct. 14, 2022, 8:49 p.m. |
| Alberti Challenge — Part 1 | 200 | March 26, 2022, 10:01 p.m. |
| Wheatstone Cryptograph — Part 1 | 200 | April 22, 2021, 2:20 a.m. |
| M-138 — Part 3 | 1,097 | Aug. 29, 2020, 1:15 p.m. |
| Lightweight Introduction to Lattices — Part 3 | 2,000 | July 16, 2020, 10 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 120 | June 28, 2020, 11:13 a.m. |
| Lightweight Introduction to Lattices — Part 1 | 200 | May 17, 2020, 2:15 p.m. |
| Polyhomophonic Substitution — Part 3 | 2,000 | April 7, 2020, 3:49 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 1,213 | March 30, 2020, 12:37 a.m. |
| Polyphonic Substitution Cipher — Part 2 | 1,251 | March 29, 2020, 6:09 p.m. |
| Polyhomophonic Substitution — Part 2 | 2,000 | March 29, 2020, 12:49 p.m. |
| Polyhomophonic Substitution — Part 1 | 200 | March 22, 2020, 8:47 a.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 2,000 | Feb. 19, 2020, 10:35 p.m. |
| Cipher ID — Part 1 | 2,000 | Nov. 19, 2019, 2:41 p.m. |
| A Cloaked Substitution Cipher — Part 2 | 2,000 | Aug. 26, 2019, 1:43 a.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,660 | Aug. 24, 2019, 5:35 p.m. |
| Handycipher made in love — Part 2 | 2,000 | May 21, 2019, 11:37 p.m. |
| Homophonic Encryption — Part 2 | 1,725 | May 11, 2019, 12:58 a.m. |
| Homophonic Encryption — Part 4 | 2,000 | May 9, 2019, 12:56 a.m. |
| Homophonic Encryption — Part 3 | 2,000 | May 9, 2019, 12:41 a.m. |
| Homophonic Encryption — Part 1 | 1,725 | May 6, 2019, 7 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 102 | March 10, 2019, 11:36 a.m. |
| Weakened Handycipher — Part 3 | 1,108 | Feb. 22, 2019, 11:32 p.m. |
| Weakened Handycipher — Part 1 | 1,108 | Feb. 22, 2019, 7:24 p.m. |
| Weakened Handycipher — Part 2 | 1,108 | Feb. 22, 2019, 6:57 p.m. |
| Handycipher made in love — Part 1 | 2,000 | Feb. 16, 2019, 11:50 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 2,000 | Feb. 16, 2019, 11:02 p.m. |
| "The Road" — Part 1 | 1,613 | Dec. 13, 2018, 3:15 p.m. |
| Catherine of Aragon's Letter to King Ferdinand, her Father (1509) | 2,000 | Dec. 11, 2018, 3:52 p.m. |
| RSA Factoring Challenge: RSA-230 | 0 | Nov. 7, 2018, 10:42 p.m. |
| Cryptanalysis Hacking Puzzles — Part 1 | 200 | Oct. 26, 2018, 10:47 p.m. |
| Breaking a Filter Generator | 1,725 | Sept. 27, 2018, 10:20 p.m. |
| Autokey Cipher | 200 | Sept. 25, 2018, 10:11 p.m. |
| Modular Sequences | 200 | Sept. 25, 2018, 9:39 p.m. |
| Trendy Messenger | 1,725 | June 14, 2018, 7:05 p.m. |
| Fastest in the West | 1,725 | June 14, 2018, 4:21 p.m. |
| Summer Job | 2,000 | June 12, 2018, 11:34 p.m. |
| Number Sequence — Part 10 | 200 | April 18, 2018, 8:31 p.m. |
| The Einstein Enigma | 1,523 | Feb. 15, 2018, 6:12 p.m. |
| Advent Challenge — Part 3 | 2,000 | Dec. 22, 2017, 7:30 p.m. |
| Advent Challenge — Part 4 | 2,000 | Dec. 21, 2017, 6:47 p.m. |
| AES ECB Wrong Encoding | 2,000 | Dec. 17, 2017, 6:10 p.m. |
| Advent-Challenge — Part 2 | 2,000 | Dec. 17, 2017, 12:30 p.m. |
| Advent-Challenge — Part 1 | 200 | Dec. 8, 2017, 10:36 p.m. |
| Number Sequence — Part 9 | 200 | Nov. 17, 2017, 2:41 p.m. |
| Holographic Encryption — Part 2 | 1,613 | April 12, 2017, 6:46 p.m. |
| Holographic Encryption — Part 1 | 1,660 | April 11, 2017, 9:41 a.m. |
| Hilly — Part 1 | 1,385 | Feb. 13, 2017, 7:33 p.m. |
| RSA Factoring Challenge: RSA-220 | 0 | Nov. 23, 2016, 11:38 a.m. |
| New Year's Greetings — Part 5 | 1,576 | March 26, 2016, 1:20 p.m. |
| New Year's Greetings — Part 4 | 133 | March 23, 2016, 10:33 p.m. |
| New Year's Greetings — Part 3 | 133 | March 23, 2016, 9:47 p.m. |
| New Year's Greetings — Part 2 | 133 | March 23, 2016, 9:28 p.m. |
| New Year's Greetings — Part 1 | 133 | March 23, 2016, 9:21 p.m. |
| Image Noise | 200 | Nov. 20, 2015, 10:18 p.m. |
| News from Castle Mansfeld | 200 | Nov. 13, 2015, 10:52 p.m. |
| Weakened Granit — Part 1 | 117 | Sept. 29, 2015, 10:17 p.m. |
| Number Sequence — Part 8 | 133 | Sept. 16, 2015, 10:07 a.m. |
| Number Sequence — Part 7 | 102 | May 6, 2015, 11:40 p.m. |
| A hidden word — Part 2 | 200 | April 16, 2015, 10:24 p.m. |
| Number Sequence — Part 6 | 200 | March 23, 2015, 3:46 p.m. |
| M-138 — Part 2 | 2,000 | Dec. 24, 2014, 1:51 p.m. |
| M-138 — Part 1 | 200 | Dec. 24, 2014, 12:52 p.m. |
| The Last Note | 200 | Sept. 23, 2014, 12:25 a.m. |
| Heartbleed — Part 3 | 1,547 | Sept. 3, 2014, 9:15 p.m. |
| Heartbleed — Part 2 | 117 | Sept. 2, 2014, 3:18 p.m. |
| Heartbleed — Part 1 | 120 | Sept. 1, 2014, 8:57 p.m. |
| Typex — Part 2 | 1,148 | July 2, 2014, 10:12 p.m. |
| Cascading Encryption — Part 3/3 | 1,148 | June 22, 2014, 10:08 p.m. |
| Cascading Encryption — Part 2/3 | 1,149 | June 9, 2014, 1:03 a.m. |
| Double Column Transposition — Part 4 | 1,824 | May 21, 2014, 10:03 a.m. |
| Double Column Transposition — Part 1 | 1,341 | May 2, 2014, 11:14 p.m. |
| Double Column Transposition — Part 3 | 2,000 | May 2, 2014, 11:01 p.m. |
| Double Column Transposition — Part 2 | 2,000 | May 2, 2014, 10:03 p.m. |
| Spanish Strip Cipher — Part 2 | 1,725 | March 30, 2014, 12:47 a.m. |
| Spanish Strip Cipher — Part 1 | 2,000 | March 28, 2014, 12:56 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 200 | March 5, 2014, 10:25 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 200 | March 5, 2014, 10:21 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 200 | March 5, 2014, 10:02 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | Nov. 27, 2013, 6:28 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 200 | Oct. 29, 2013, 1:39 a.m. |
| Trifid Cipher | 200 | Oct. 29, 2013, 1:09 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 200 | Sept. 26, 2013, 9:57 p.m. |
| Hill Cipher with Sudoku Key | 120 | Sept. 8, 2013, 9:59 p.m. |
| From Russia with Love | 120 | Sept. 8, 2013, 7:33 p.m. |
| Nils away on travel | 200 | Aug. 8, 2013, 1:43 p.m. |
| RSA Factoring Challenge: RSA-704 | 0 | July 31, 2013, 7:30 p.m. |
| ORYX Stream Cipher — Part 3 (revised) | 2,000 | June 6, 2013, 10:17 p.m. |
| Notes of an Italian Soldier | 800 | May 4, 2013, 10:57 p.m. |
| Snow White and the seven dwarfs | 200 | April 20, 2013, 2:49 p.m. |
| Typex — Part 1 | 1,378 | March 20, 2013, 6:57 p.m. |
| Reserve Hand Procedure — Part 1 | 200 | March 6, 2013, 10:41 p.m. |
| Multilingual Monoalphabetic Substitution | 200 | Jan. 31, 2013, 1:07 a.m. |
| Cascading Encryption — Part 1/3 | 200 | Jan. 25, 2013, 3:50 p.m. |
| Enigma Messages | 200 | Jan. 23, 2013, 6:33 p.m. |
| Akelarre Part 1 | 1,126 | Jan. 18, 2013, 7:16 p.m. |
| Playfair with hints about the grid | 200 | Jan. 16, 2013, 6:13 p.m. |
| A hidden word | 200 | Jan. 6, 2013, 3:49 p.m. |
| Strange Message from Thessaloniki | 200 | Dec. 10, 2012, 9:35 p.m. |
| Recycled One-Time Pad | 114 | Nov. 26, 2012, 11:22 p.m. |
| Letter to the Templars — Part 3 | 2,000 | Oct. 9, 2012, 5:40 p.m. |
| BCR code (Book-Caesar-RSA) | 2,000 | Sept. 13, 2012, 3:09 a.m. |
| Beaver Code | 200 | Aug. 13, 2012, 9:17 p.m. |
| Letter to the Templars — Part 2 | 200 | July 30, 2012, 8:56 p.m. |
| Letter to the Templars — Part 1 | 200 | July 16, 2012, 10:14 p.m. |
| Keyshanc — Part 2 | 2,000 | May 21, 2012, 11:15 p.m. |
| Keyshanc — Part 1 | 2,000 | May 21, 2012, 10:46 p.m. |
| Concealed Messages — Vigenère's Night Sky | 2,000 | May 4, 2012, 3:23 a.m. |
| Number Sequence — Part 5 | 114 | April 24, 2012, 7:50 p.m. |
| Number Sequence — Part 4 | 114 | April 24, 2012, 7:50 p.m. |
| ¿No Hablas Español? No problemo! | 200 | April 18, 2012, 8:40 p.m. |
| Number Sequence — Part 3 | 200 | March 30, 2012, 11:56 p.m. |
| The Book Code: A Challenge for Bookworms | 200 | March 21, 2012, 2:09 p.m. |
| CMEA 2 | 14,086 | March 11, 2012, 1:41 p.m. |
| CMEA 1 | 1,147 | March 6, 2012, 2 p.m. |
| RSA with Special d | 14,042 | Feb. 24, 2012, 9:52 p.m. |
| ECDH-Key Exchange for Beginners | 200 | Feb. 24, 2012, 1:30 a.m. |
| Partial Key Exposure with RSA — Part 1 | 2,000 | Feb. 11, 2012, 1:32 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 2,000 | Jan. 17, 2012, 3:26 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 2 | 1,179 | Dec. 4, 2011, 2:39 a.m. |
| Ku Klux Klan | 1,000 | Nov. 8, 2011, 1:52 p.m. |
| Zodiac Cipher | 100 | Oct. 19, 2011, 6:23 p.m. |
| Turing Bombe Enigma I | 200 | Oct. 18, 2011, 2:18 a.m. |
| Grille Cipher | 200 | Oct. 14, 2011, 7:55 p.m. |
| Double Columnar Transposition | 200 | Oct. 13, 2011, 1:28 p.m. |
| Enigma Combinatorics | 100 | Oct. 3, 2011, 3 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Sept. 22, 2011, 1:35 a.m. |
| Kaskade-S/T — Part 3 | 1,188 | Sept. 18, 2011, 5:04 p.m. |
| Kaskade-S/T — Part 2 | 1,188 | Sept. 17, 2011, 11:18 p.m. |
| Kaskade-S/T — Part 1 | 101 | Sept. 17, 2011, 4:33 p.m. |
| Pigpen with a twist — Part 2 | 1,423 | Sept. 17, 2011, 12:59 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Sept. 13, 2011, 6:22 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Sept. 13, 2011, 6 p.m. |
| Classical Ciphers^3 | 100 | Sept. 13, 2011, 3:08 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Sept. 11, 2011, 10:46 p.m. |
| Pigpen with a twist — Part 3 | 1,485 | Sept. 11, 2011, 2:50 p.m. |
| Molehunt (Part 3/3) | 1,163 | Sept. 9, 2011, 7:37 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,162 | Sept. 9, 2011, 6:07 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 200 | Sept. 9, 2011, 1:49 p.m. |
| Pigpen with a twist — Part 1 | 200 | Sept. 5, 2011, 10:17 p.m. |
| Molehunt (Part 2/3) | 100 | Sept. 5, 2011, 4:44 p.m. |
| Molehunt (Part 1/3) | 100 | Sept. 2, 2011, 9:48 p.m. |
| Enigma Part 1 | 1,163 | Sept. 1, 2011, 11:28 p.m. |
| Enigma Part 2 | 1,163 | Sept. 1, 2011, 1:22 p.m. |
| ORYX Stream Cipher Part II | 1,163 | Aug. 30, 2011, 2:58 a.m. |
| Cracking SHA1-Hashed Passwords | 1,207 | Aug. 25, 2011, 2:37 p.m. |
| ORYX Stream Cipher Part I | 1,165 | Aug. 21, 2011, 12:03 a.m. |
| Smartcard RSA | 1,167 | Aug. 18, 2011, 5:32 p.m. |
| ADFGVX — Part 2 | 200 | Aug. 16, 2011, 3:13 a.m. |
| ADFGVX — Part 1 | 200 | Aug. 16, 2011, 2:35 a.m. |
| RSA: Two different keys — same ciphertext | 2,000 | Aug. 15, 2011, 8:15 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,166 | Aug. 13, 2011, 9:18 p.m. |
| Playfair Encryption | 100 | Aug. 13, 2011, 1:21 a.m. |
| Monoalphabetic Substitution | 100 | Aug. 12, 2011, 8:57 p.m. |
| Music Code — Part 2 | 1,240 | Aug. 12, 2011, 5:21 p.m. |
| Music Code — Part 1 | 101 | Aug. 10, 2011, 7:46 a.m. |
| Lattice Part 1 | 1,203 | Aug. 9, 2011, 8:54 p.m. |
| Hybrid Encryption I | 1,170 | Aug. 9, 2011, 1:10 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,186 | Aug. 8, 2011, 8:07 p.m. |
| One-Time Pad with Flaws | 100 | Aug. 8, 2011, 3:10 a.m. |
| Alice's Birthday Party (Part 2) | 1,168 | July 31, 2011, 12:03 a.m. |
| Alice's Birthday Party (Part 1) | 1,168 | July 30, 2011, 11:35 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,523 | July 30, 2011, 2:18 a.m. |
| Caesar Encryption | 100 | July 30, 2011, 12:33 a.m. |
| Original Caesar Cipher | 100 | July 29, 2011, 9:37 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 101 | July 29, 2011, 2:44 p.m. |
| Number Sequence — Part 2 | 106 | July 28, 2011, 9:14 p.m. |
| Number Sequence | 100 | July 28, 2011, 9:08 p.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,169 | July 27, 2011, 5:16 p.m. |
Gold28
Silver23
Bronze19
