| Alberti Challenge — Part 1 | 100 | Oct. 28, 2022, 1:10 a.m. |
| RSA Factoring Challenge: RSA-250 | 0 | March 2, 2022, 3:01 p.m. |
| RSA Factoring Challenge: RSA-240 | 0 | March 2, 2022, 3:01 p.m. |
| RSA Factoring Challenge: RSA-232 | 0 | March 2, 2022, 2:59 p.m. |
| Polyphonic Substitution Cipher — Part 2 | 1,127 | March 2, 2022, 2:44 p.m. |
| Polyhomophonic Substitution — Part 2 | 1,130 | March 1, 2022, 1:08 a.m. |
| Polyhomophonic Substitution — Part 1 | 100 | Feb. 28, 2022, 11:37 p.m. |
| Lightweight Introduction to Lattices — Part 3 | 1,137 | Feb. 28, 2022, 10:46 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 100 | Feb. 28, 2022, 10:40 p.m. |
| Lightweight Introduction to Lattices — Part 1 | 100 | Feb. 28, 2022, 10:09 p.m. |
| Wheatstone Cryptograph — Part 2 | 1,203 | Oct. 21, 2021, 2:17 p.m. |
| Wheatstone Cryptograph — Part 1 | 101 | Oct. 16, 2021, 4:22 a.m. |
| Find the right route — Part 3 | 100 | Sept. 24, 2021, 2:29 a.m. |
| Find the right route — Part 2 | 100 | Sept. 23, 2021, 11:22 p.m. |
| Find the right route — Part 1 | 100 | Sept. 23, 2021, 9:33 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 1,725 | Nov. 23, 2019, 3:02 p.m. |
| AES ECB Wrong Encoding | 1,130 | Nov. 20, 2019, 1:25 p.m. |
| Cipher ID — Part 1 | 2,000 | Nov. 19, 2019, 1:05 p.m. |
| Hilly — Part 1 | 1,119 | Sept. 19, 2019, 7:08 a.m. |
| Double Column Transposition — Part 5 | 1,099 | Sept. 12, 2019, 5:27 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,185 | Sept. 11, 2019, 6:27 p.m. |
| A Cloaked Substitution Cipher — Part 2 | 1,502 | Sept. 3, 2019, 8:22 a.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,725 | Aug. 24, 2019, 12:59 a.m. |
| Handycipher made in love — Part 2 | 1,244 | Aug. 11, 2019, 11:04 p.m. |
| Breaking a Filter Generator | 1,164 | Aug. 6, 2019, 4:56 p.m. |
| Handycipher made in love — Part 1 | 1,199 | July 29, 2019, 5:55 a.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,444 | July 26, 2019, 4:40 p.m. |
| Homophonic Encryption — Part 4 | 1,251 | July 23, 2019, 2:41 a.m. |
| Homophonic Encryption — Part 3 | 1,251 | July 23, 2019, 1:31 a.m. |
| Homophonic Encryption — Part 2 | 1,251 | July 23, 2019, 12:42 a.m. |
| Homophonic Encryption — Part 1 | 1,247 | July 22, 2019, 11:32 p.m. |
| Fastest in the West | 1,153 | July 22, 2019, 9:37 p.m. |
| Trendy Messenger | 1,153 | July 22, 2019, 5:30 p.m. |
| RSA Factoring Challenge: RSA-230 | 0 | July 22, 2019, 12:28 p.m. |
| Modular Sequences | 100 | July 22, 2019, 5:03 a.m. |
| Advent Challenge — Part 4 | 1,138 | July 17, 2019, 5:45 p.m. |
| Advent Challenge — Part 3 | 1,138 | July 17, 2019, 3:37 a.m. |
| Advent-Challenge — Part 2 | 1,138 | July 17, 2019, 2:45 a.m. |
| Summer Job | 1,153 | July 16, 2019, 5:21 a.m. |
| The Einstein Enigma | 1,142 | July 16, 2019, 3:33 a.m. |
| Number Sequence — Part 10 | 100 | July 16, 2019, 1:09 a.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 101 | July 16, 2019, 12:48 a.m. |
| Autokey Cipher | 100 | July 15, 2019, 11:54 p.m. |
| Advent-Challenge — Part 1 | 117 | Dec. 14, 2017, 7:02 p.m. |
| ASAC — A Strong(er) ADFGVX Cipher — Part 1 | 1,143 | Nov. 29, 2017, 12:40 a.m. |
| Number Sequence — Part 9 | 114 | Nov. 23, 2017, 1:22 p.m. |
| Holographic Encryption — Part 1 | 1,198 | Sept. 20, 2017, 3:18 a.m. |
| M-138 — Part 4 | 1,127 | Jan. 31, 2017, 2:56 p.m. |
| RSA Factoring Challenge: RSA-220 | 0 | Jan. 25, 2017, 7:34 p.m. |
| New Year's Greetings — Part 4 | 101 | June 28, 2016, 12:29 a.m. |
| New Year's Greetings — Part 3 | 101 | June 28, 2016, 12:25 a.m. |
| New Year's Greetings — Part 2 | 101 | June 28, 2016, 12:18 a.m. |
| New Year's Greetings — Part 1 | 101 | June 28, 2016, 12:02 a.m. |
| News from Castle Mansfeld | 111 | Nov. 21, 2015, 7:34 p.m. |
| Image Noise | 200 | Nov. 21, 2015, 2:53 p.m. |
| Weakened Granit — Part 1 | 200 | Sept. 24, 2015, 11:19 p.m. |
| Number Sequence — Part 8 | 200 | Sept. 14, 2015, 4:31 p.m. |
| Flawed Usage of a OTP Cipher by the BND | 1,398 | Sept. 10, 2015, 2:30 p.m. |
| Number Sequence — Part 7 | 101 | Sept. 10, 2015, 7 a.m. |
| A hidden word — Part 2 | 150 | April 17, 2015, 10:31 p.m. |
| Number Sequence — Part 6 | 120 | March 28, 2015, 1:58 a.m. |
| M-138 — Part 3 | 2,000 | Dec. 24, 2014, 9:59 a.m. |
| M-138 — Part 2 | 2,000 | Dec. 24, 2014, 3:37 a.m. |
| M-138 — Part 1 | 200 | Dec. 24, 2014, 1:44 a.m. |
| The Last Note | 200 | Sept. 23, 2014, 2:55 p.m. |
| Heartbleed — Part 3 | 1,547 | Sept. 4, 2014, 12:54 a.m. |
| Heartbleed — Part 2 | 117 | Sept. 2, 2014, 4:24 p.m. |
| Heartbleed — Part 1 | 125 | Sept. 1, 2014, 10:39 a.m. |
| CMEA 2 | 13,551 | June 4, 2014, 12:37 p.m. |
| Cascading Encryption — Part 3/3 | 1,150 | June 2, 2014, 2:03 a.m. |
| Cascading Encryption — Part 2/3 | 1,150 | June 1, 2014, 11:10 a.m. |
| Double Column Transposition — Part 3 | 1,367 | May 25, 2014, 1:26 a.m. |
| Double Column Transposition — Part 1 | 1,284 | May 25, 2014, 1:07 a.m. |
| Double Column Transposition — Part 4 | 2,000 | May 20, 2014, 5:13 a.m. |
| Purple 1 | 1,110 | May 20, 2014, 1:08 a.m. |
| Double Column Transposition — Part 2 | 1,469 | May 12, 2014, 10:43 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | April 23, 2014, 4:20 p.m. |
| RSA Factoring Challenge: RSA-704 | 0 | April 23, 2014, 4:10 p.m. |
| ORYX Stream Cipher — Part 3 (revised) | 1,163 | April 22, 2014, 11:36 p.m. |
| Spanish Strip Cipher — Part 2 | 1,660 | March 31, 2014, 11:26 a.m. |
| Spanish Strip Cipher — Part 1 | 1,660 | March 31, 2014, 5:04 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 133 | March 8, 2014, 1:05 a.m. |
| Enigma Messages with Repeated Letters — Part 4 | 133 | March 8, 2014, 12:38 a.m. |
| Enigma Messages with Repeated Letters — Part 3 | 133 | March 8, 2014, 12:26 a.m. |
| Akelarre Part 1 | 1,115 | Dec. 14, 2013, 2:10 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 107 | Nov. 11, 2013, 10:48 p.m. |
| Trifid Cipher | 150 | Oct. 30, 2013, 7:22 p.m. |
| Kaskade-S/T — Part 5 | 1,122 | Oct. 7, 2013, 5:34 a.m. |
| Typex — Part 2 | 1,193 | Oct. 2, 2013, 12:16 a.m. |
| Typex — Part 1 | 1,184 | Oct. 1, 2013, 1:01 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 133 | Sept. 29, 2013, 2:39 a.m. |
| Multilingual Monoalphabetic Substitution | 100 | Sept. 14, 2013, 4:06 p.m. |
| Hill Cipher with Sudoku Key | 111 | Sept. 12, 2013, 11:07 p.m. |
| From Russia with Love | 117 | Sept. 9, 2013, 6:38 p.m. |
| Nils away on travel | 200 | Aug. 9, 2013, 11:09 a.m. |
| Snow White and the seven dwarfs | 150 | April 21, 2013, 11:05 p.m. |
| Reserve Hand Procedure — Part 1 | 200 | March 7, 2013, 12:59 a.m. |
| CMEA 1 | 1,126 | Feb. 1, 2013, 1:07 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 2 | 1,133 | Jan. 27, 2013, 11:02 p.m. |
| Cascading Encryption — Part 1/3 | 200 | Jan. 25, 2013, 8:50 p.m. |
| Enigma Messages | 150 | Jan. 24, 2013, 4:40 p.m. |
| Playfair with hints about the grid | 200 | Jan. 17, 2013, 11 a.m. |
| A hidden word | 200 | Jan. 6, 2013, 3:42 p.m. |
| Concealed Messages — Vigenère's Night Sky | 1,179 | Dec. 21, 2012, 1:17 a.m. |
| Strange Message from Thessaloniki | 200 | Dec. 11, 2012, 12:52 a.m. |
| Recycled One-Time Pad | 114 | Nov. 27, 2012, 3:02 a.m. |
| Kaskade-S/T — Part 3 | 1,135 | Nov. 23, 2012, 3:57 a.m. |
| Zodiac Cipher | 100 | Nov. 21, 2012, 12:10 p.m. |
| Letter to the Templars — Part 3 | 2,000 | Oct. 9, 2012, 4:24 p.m. |
| BCR code (Book-Caesar-RSA) | 1,824 | Sept. 14, 2012, 10:58 a.m. |
| Beaver Code | 200 | Aug. 14, 2012, 12:23 a.m. |
| Letter to the Templars — Part 2 | 120 | Aug. 3, 2012, 9:39 p.m. |
| RSA with Special d | 13,897 | July 23, 2012, 9:45 a.m. |
| Unconcealed RSA messages | 1,174 | July 18, 2012, 9:16 p.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,134 | July 17, 2012, 1:35 p.m. |
| Letter to the Templars — Part 1 | 200 | July 17, 2012, 2:19 a.m. |
| Enigma Part 2 | 1,134 | July 12, 2012, 3:20 a.m. |
| Lattice Part 1 | 1,145 | July 11, 2012, 8:12 p.m. |
| An 'unhearable' message | 150 | June 6, 2012, 11:58 p.m. |
| How do you become a big cryptographer? | 200 | May 29, 2012, 1:45 a.m. |
| Keyshanc — Part 2 | 1,725 | May 24, 2012, 11:54 a.m. |
| Keyshanc — Part 1 | 1,725 | May 24, 2012, 11:12 a.m. |
| Number Sequence — Part 5 | 114 | April 24, 2012, 10:52 p.m. |
| Number Sequence — Part 4 | 114 | April 24, 2012, 10:50 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,234 | April 20, 2012, 8:30 p.m. |
| Pigpen with a twist — Part 3 | 1,180 | April 19, 2012, 12:19 p.m. |
| Pigpen with a twist — Part 2 | 1,180 | April 19, 2012, 12:01 p.m. |
| Number Sequence — Part 3 | 150 | April 1, 2012, 1:37 a.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,378 | March 30, 2012, 11:45 a.m. |
| The Book Code: A Challenge for Bookworms | 150 | March 22, 2012, 11:24 a.m. |
| Smartcard RSA | 1,145 | Feb. 26, 2012, 1:17 a.m. |
| ORYX Stream Cipher Part II | 1,144 | Feb. 25, 2012, 5:40 a.m. |
| ECDH-Key Exchange for Beginners | 200 | Feb. 24, 2012, 5:01 a.m. |
| ORYX Stream Cipher Part I | 1,144 | Feb. 24, 2012, 2:11 a.m. |
| Music Code — Part 2 | 1,171 | Feb. 14, 2012, 12:10 a.m. |
| Music Code — Part 1 | 100 | Feb. 14, 2012, 12:08 a.m. |
| Partial Key Exposure with RSA — Part 1 | 2,000 | Feb. 11, 2012, 1:23 p.m. |
| Ku Klux Klan | 1,000 | Feb. 10, 2012, 6:45 p.m. |
| A really long number sequence | 1,203 | Feb. 5, 2012, 2:32 p.m. |
| Unusual encryption using a diophantine equation | 1,202 | Feb. 5, 2012, 2:46 a.m. |
| Playfair Encryption | 100 | Jan. 31, 2012, 12:55 a.m. |
| Factorization Cipher — Part 3 | 1,824 | Jan. 8, 2012, 9:32 a.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,160 | Dec. 26, 2011, 6:49 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 200 | Dec. 22, 2011, 1:18 p.m. |
| Kaskade-S/T — Part 2 | 1,169 | Dec. 14, 2011, 4:38 p.m. |
| Enigma Part 1 | 1,151 | Dec. 12, 2011, 9:11 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,824 | Dec. 8, 2011, 9:15 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,824 | Dec. 8, 2011, 5:06 p.m. |
| Pigpen with a twist — Part 1 | 101 | Dec. 8, 2011, 1:19 a.m. |
| RSA: Two different keys — same ciphertext | 1,222 | Dec. 7, 2011, 3:44 p.m. |
| Molehunt (Part 3/3) | 1,152 | Dec. 5, 2011, 10:14 p.m. |
| Factorization Cipher — Part 2 | 1,660 | Dec. 5, 2011, 11:14 a.m. |
| Double Columnar Transposition | 102 | Nov. 30, 2011, 1:04 a.m. |
| Cracking SHA1-Hashed Passwords | 1,178 | Nov. 28, 2011, 1:12 p.m. |
| Hybrid Encryption I | 1,154 | Nov. 28, 2011, 12:38 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,152 | Nov. 27, 2011, 9:31 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,219 | Nov. 18, 2011, 3:55 a.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,153 | Nov. 18, 2011, 2:34 a.m. |
| Alice's Birthday Party (Part 2) | 1,153 | Nov. 16, 2011, 2:55 a.m. |
| Alice's Birthday Party (Part 1) | 1,154 | Nov. 14, 2011, 11:50 p.m. |
| An Invisible Message | 103 | Nov. 14, 2011, 8:37 p.m. |
| Turing Bombe Enigma I | 104 | Nov. 9, 2011, 1:51 a.m. |
| ADFGVX — Part 2 | 101 | Nov. 9, 2011, 12:49 a.m. |
| ADFGVX — Part 1 | 101 | Nov. 8, 2011, 6:36 a.m. |
| Classical Ciphers^3 | 100 | Nov. 8, 2011, 5:44 a.m. |
| Molehunt (Part 2/3) | 100 | Nov. 8, 2011, 1:25 a.m. |
| A Secret Message from Castle Mansfeld | 100 | Nov. 5, 2011, 5:52 p.m. |
| Factorization Cipher — Part 1 | 105 | Nov. 4, 2011, 11:17 p.m. |
| Modified Caesar Cipher | 102 | Nov. 4, 2011, 4:13 p.m. |
| Enigma Combinatorics | 100 | Nov. 4, 2011, 1:51 a.m. |
| Grille Cipher | 105 | Nov. 4, 2011, 12:27 a.m. |
| Molehunt (Part 1/3) | 100 | Nov. 3, 2011, 9:02 p.m. |
| Kaskade-S/T — Part 1 | 100 | Nov. 3, 2011, 5:36 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 102 | Nov. 2, 2011, 6:01 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Nov. 2, 2011, 3:19 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Nov. 2, 2011, 1:56 a.m. |
| One-Time Pad with Flaws | 100 | Nov. 1, 2011, 10:51 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Nov. 1, 2011, 9:23 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 117 | Nov. 1, 2011, 7:39 p.m. |
| Number Sequence — Part 2 | 101 | Nov. 1, 2011, 2:27 p.m. |
| Original Caesar Cipher | 100 | Nov. 1, 2011, 2:25 p.m. |
| Caesar Encryption | 100 | Nov. 1, 2011, 2:23 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Nov. 1, 2011, 2:10 p.m. |
| Monoalphabetic Substitution | 100 | Nov. 1, 2011, 2:06 p.m. |
| Number Sequence | 100 | Nov. 1, 2011, 12:48 p.m. |
Gold7
Silver7
Bronze4
