| The Hutton Cipher – Part 1 | 1,547 | May 9, 2023, 2:38 p.m. |
| The Josse Challenge – Part 3 | 1,660 | March 30, 2023, 6 p.m. |
| The Josse Challenge – Part 2 | 1,660 | Feb. 28, 2023, 11:12 a.m. |
| The Josse Challenge – Part 1 | 1,547 | Feb. 16, 2023, 3:14 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,080 | Feb. 2, 2023, 6:24 p.m. |
| ASAC — A Strong(er) ADFGVX Cipher — Part 1 | 1,093 | Jan. 30, 2023, 4:09 p.m. |
| Handycipher made in love — Part 2 | 1,109 | Jan. 27, 2023, 11:06 a.m. |
| RSA Factoring Challenge: RSA-232 | 0 | Jan. 21, 2023, 2:59 p.m. |
| RSA Factoring Challenge: RSA-240 | 0 | Jan. 21, 2023, 2:58 p.m. |
| RSA Factoring Challenge: RSA-250 | 0 | Jan. 21, 2023, 2:57 p.m. |
| RSA Factoring Challenge: RSA-230 | 0 | Jan. 21, 2023, 2:53 p.m. |
| RSA Factoring Challenge: RSA-220 | 0 | Jan. 21, 2023, 2:52 p.m. |
| Handycipher made in love — Part 1 | 1,107 | Jan. 20, 2023, 4:10 p.m. |
| Hill Cipher | 1,210 | Jan. 18, 2023, 3:44 p.m. |
| Merkle-Hellman Knapsack Challenge — Part 2 | 1,238 | Jan. 13, 2023, 3:06 p.m. |
| The Syllabary Cipher – Part 2 | 1,281 | Dec. 19, 2022, 7:10 p.m. |
| The Syllabary Cipher – Part 1 | 102 | Dec. 12, 2022, 5:10 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 102 | Dec. 9, 2022, 5:32 p.m. |
| Alberti Challenge — Part 1 | 117 | April 1, 2022, 6:30 p.m. |
| Holographic Encryption — Part 1 | 1,100 | March 22, 2022, 5:35 p.m. |
| The SZ42 Challenge — Part 11 | 1,152 | March 18, 2022, 5:06 p.m. |
| The SZ42 Challenge — Part 13 | 1,202 | March 11, 2022, 4:01 p.m. |
| The SZ42 Challenge — Part 12 | 1,202 | March 10, 2022, 4:49 p.m. |
| The SZ42 Challenge — Part 10 | 1,153 | March 9, 2022, 5:13 p.m. |
| The SZ42 Challenge — Part 9 | 1,150 | Feb. 26, 2022, 4:32 p.m. |
| The SZ42 Challenge — Part 8 | 1,145 | Feb. 25, 2022, 2:24 p.m. |
| The SZ42 Challenge — Part 7 | 1,145 | Feb. 25, 2022, 2:05 p.m. |
| The SZ42 Challenge — Part 6 | 1,143 | Feb. 24, 2022, 2:02 p.m. |
| The SZ42 Challenge — Part 5 | 1,141 | Feb. 22, 2022, 5:02 p.m. |
| The SZ42 Challenge — Part 4 | 1,140 | Feb. 22, 2022, 4:49 p.m. |
| The SZ42 Challenge — Part 3 | 1,140 | Feb. 16, 2022, 7:29 p.m. |
| The SZ42 Challenge — Part 2 | 1,139 | Feb. 14, 2022, 4:32 p.m. |
| The SZ42 Challenge — Part 1 | 1,138 | Feb. 12, 2022, 5:18 p.m. |
| Breaking a Filter Generator | 1,119 | June 4, 2021, 7:29 p.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 1,147 | May 25, 2021, 6:35 p.m. |
| Find the right route — Part 1 | 100 | May 20, 2021, 7:43 p.m. |
| AES ECB Wrong Encoding | 1,111 | May 20, 2021, 5:54 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | May 19, 2021, 7:50 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 100 | May 18, 2021, 6:27 p.m. |
| Cryptanalysis Hacking Puzzles — Part 1 | 100 | May 18, 2021, 10:12 a.m. |
| Lightweight Introduction to Lattices — Part 1 | 100 | May 17, 2021, 7:29 p.m. |
| Homophonic Encryption — Part 4 | 1,129 | May 16, 2021, 5:49 p.m. |
| Homophonic Encryption — Part 3 | 1,129 | May 14, 2021, 6:17 p.m. |
| Homophonic Encryption — Part 2 | 1,129 | May 13, 2021, 8:11 p.m. |
| Homophonic Encryption — Part 1 | 1,129 | May 11, 2021, 5:51 p.m. |
| Lightweight Introduction to Lattices — Part 3 | 1,167 | May 10, 2021, 10:22 a.m. |
| Polyphonic Substitution Cipher — Part 2 | 1,146 | May 6, 2021, 1:33 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 1,141 | May 3, 2021, 6:39 p.m. |
| Polyhomophonic Substitution — Part 3 | 1,154 | May 1, 2021, 6:20 p.m. |
| Polyhomophonic Substitution — Part 2 | 1,153 | May 1, 2021, 5:29 p.m. |
| Polyhomophonic Substitution — Part 1 | 100 | April 29, 2021, 4:20 p.m. |
| Wheatstone Cryptograph — Part 1 | 120 | April 26, 2021, 5:03 p.m. |
| The T52 Sturgeon Challenge — Part 4 | 1,203 | Dec. 22, 2019, 1:48 p.m. |
| The T52 Sturgeon Challenge — Part 3 | 1,204 | Dec. 19, 2019, 1:52 p.m. |
| The T52 Sturgeon Challenge — Part 2 | 1,208 | Dec. 11, 2019, 6:04 p.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,204 | Dec. 10, 2019, 2:42 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,660 | Feb. 19, 2019, 1:04 p.m. |
| M-138 — Part 4 | 1,106 | Dec. 24, 2018, 9:17 a.m. |
| M-138 — Part 3 | 1,106 | Dec. 21, 2018, 6:37 p.m. |
| Weakened Granit — Part 1 | 100 | Dec. 21, 2018, 12:54 p.m. |
| Image Noise | 100 | Dec. 20, 2018, 9:56 a.m. |
| The Einstein Enigma | 1,164 | Dec. 19, 2018, 4:17 p.m. |
| Advent Challenge — Part 4 | 1,158 | Dec. 18, 2018, 2:22 p.m. |
| Advent Challenge — Part 3 | 1,158 | Dec. 18, 2018, 9:34 a.m. |
| Advent-Challenge — Part 2 | 1,157 | Dec. 17, 2018, 6:06 p.m. |
| Number Sequence — Part 9 | 100 | Dec. 17, 2018, 1:01 p.m. |
| Summer Job | 1,191 | Dec. 17, 2018, 12:59 p.m. |
| Advent-Challenge — Part 1 | 100 | Dec. 16, 2018, 11:05 a.m. |
| Fastest in the West | 1,191 | Dec. 16, 2018, 10:43 a.m. |
| Trendy Messenger | 1,191 | Dec. 15, 2018, 7:54 p.m. |
| Number Sequence — Part 10 | 101 | Oct. 16, 2018, 1:29 p.m. |
| Modular Sequences | 106 | Oct. 11, 2018, 2:59 p.m. |
| Autokey Cipher | 107 | Oct. 9, 2018, 9:55 a.m. |
| Double Column Transposition — Part 4 | 1,139 | Nov. 29, 2015, 12:56 p.m. |
| Double Column Transposition — Part 3 | 1,139 | Nov. 16, 2015, 2:20 p.m. |
| Number Sequence — Part 8 | 107 | Sept. 28, 2015, 9:54 a.m. |
| Number Sequence — Part 6 | 101 | June 6, 2015, 6:36 p.m. |
| Number Sequence — Part 7 | 101 | June 1, 2015, 4:12 p.m. |
| M-138 — Part 2 | 1,576 | Dec. 29, 2014, 1:53 p.m. |
| M-138 — Part 1 | 120 | Dec. 28, 2014, 10:39 a.m. |
| RSA Factoring Challenge: RSA-210 | 0 | Sept. 23, 2014, 10:27 p.m. |
| Heartbleed — Part 3 | 1,523 | Sept. 4, 2014, 10:21 p.m. |
| Heartbleed — Part 2 | 114 | Sept. 3, 2014, 11:18 p.m. |
| Heartbleed — Part 1 | 114 | Sept. 3, 2014, 4:40 p.m. |
| Double Column Transposition — Part 2 | 1,259 | July 9, 2014, 6:33 p.m. |
| Double Column Transposition — Part 1 | 1,234 | July 8, 2014, 6:49 p.m. |
| Spanish Strip Cipher — Part 2 | 1,469 | April 7, 2014, 1:47 p.m. |
| Spanish Strip Cipher — Part 1 | 1,469 | April 7, 2014, 10:06 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 110 | March 14, 2014, 6:07 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 110 | March 14, 2014, 6:06 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 111 | March 13, 2014, 5:03 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 111 | Nov. 6, 2013, 2:01 p.m. |
| Trifid Cipher | 111 | Nov. 6, 2013, 10:19 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 150 | Sept. 28, 2013, 11:40 a.m. |
| Hill Cipher with Sudoku Key | 125 | Sept. 8, 2013, 4:04 p.m. |
| From Russia with Love | 125 | Sept. 8, 2013, 10:18 a.m. |
| Sigaba Part 1 | 1,117 | Aug. 26, 2013, 12:14 p.m. |
| Nils away on travel | 150 | Aug. 9, 2013, 2:17 p.m. |
| RSA Factoring Challenge: RSA-704 | 0 | Aug. 1, 2013, 9:37 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | July 21, 2013, 4:18 p.m. |
| Purple 1 | 1,118 | July 20, 2013, 5:56 p.m. |
| Strange Message from Thessaloniki | 100 | July 8, 2013, 9:27 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | July 3, 2013, 9:30 a.m. |
| A Secret Message from Castle Mansfeld | 100 | June 30, 2013, 5:38 p.m. |
| Enigma Combinatorics | 100 | June 29, 2013, 3:31 p.m. |
| Classical Ciphers^3 | 100 | June 29, 2013, 9:43 a.m. |
| ORYX Stream Cipher — Part 3 (revised) | 1,523 | June 13, 2013, 10:19 p.m. |
| ORYX Stream Cipher Part II | 1,120 | May 31, 2013, 12:51 p.m. |
| Music Code — Part 1 | 100 | April 25, 2013, 2:38 p.m. |
| Music Code — Part 2 | 1,130 | April 25, 2013, 10:20 a.m. |
| Snow White and the seven dwarfs | 133 | April 22, 2013, 11:39 a.m. |
| Cascading Encryption — Part 3/3 | 1,485 | April 8, 2013, 11:32 a.m. |
| Typex — Part 2 | 1,725 | April 5, 2013, 9:50 p.m. |
| Monoalphabetic Substitution | 100 | April 1, 2013, 3:08 p.m. |
| Cascading Encryption — Part 2/3 | 1,547 | March 31, 2013, 8:34 p.m. |
| Double Columnar Transposition | 100 | March 25, 2013, 9:16 a.m. |
| Molehunt (Part 3/3) | 1,123 | March 21, 2013, 1:56 p.m. |
| Molehunt (Part 2/3) | 100 | March 21, 2013, 10:41 a.m. |
| Molehunt (Part 1/3) | 100 | March 20, 2013, 1:58 p.m. |
| ADFGVX — Part 1 | 100 | March 20, 2013, 1:12 p.m. |
| Cascading Encryption — Part 1/3 | 102 | March 19, 2013, 9:09 a.m. |
| Playfair with hints about the grid | 102 | March 17, 2013, 2:44 p.m. |
| Zodiac Cipher | 100 | March 12, 2013, 1:10 p.m. |
| Typex — Part 1 | 1,456 | March 12, 2013, 9:42 a.m. |
| Reserve Hand Procedure — Part 1 | 200 | March 7, 2013, 9:46 a.m. |
| Multilingual Monoalphabetic Substitution | 103 | Feb. 28, 2013, 10:46 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 2 | 1,132 | Feb. 23, 2013, 3:23 p.m. |
| Enigma Messages | 117 | Jan. 29, 2013, 1:38 p.m. |
| A hidden word | 200 | Jan. 7, 2013, 1:37 p.m. |
| Recycled One-Time Pad | 109 | Dec. 1, 2012, 9:43 a.m. |
| Letter to the Templars — Part 3 | 2,000 | Oct. 10, 2012, 10:34 a.m. |
| CMEA 2 | 13,882 | Oct. 2, 2012, 4:30 p.m. |
| BCR code (Book-Caesar-RSA) | 1,824 | Sept. 13, 2012, 6:37 p.m. |
| Beaver Code | 200 | Aug. 14, 2012, 10:01 a.m. |
| CMEA 1 | 1,136 | Aug. 11, 2012, 5:17 p.m. |
| RSA with Special d | 13,887 | Aug. 4, 2012, 4:30 p.m. |
| Letter to the Templars — Part 2 | 200 | July 31, 2012, 5:30 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,140 | July 21, 2012, 4:36 p.m. |
| Number Sequence — Part 5 | 101 | July 17, 2012, 1:45 p.m. |
| Letter to the Templars — Part 1 | 200 | July 17, 2012, 11:23 a.m. |
| Kaskade-S/T — Part 2 | 1,144 | July 6, 2012, 6:08 p.m. |
| Pigpen with a twist — Part 1 | 100 | June 20, 2012, 3:28 p.m. |
| ADFGVX — Part 2 | 100 | June 19, 2012, 11:12 a.m. |
| Playfair Encryption | 100 | June 16, 2012, 5:48 p.m. |
| A really long number sequence | 1,170 | June 13, 2012, 11:44 a.m. |
| Turing Bombe Enigma I | 100 | June 10, 2012, 4:57 p.m. |
| Enigma Part 1 | 1,136 | June 8, 2012, 11:28 a.m. |
| Keyshanc — Part 2 | 1,414 | June 6, 2012, 8:46 p.m. |
| How do you become a big cryptographer? | 110 | June 6, 2012, 8:36 p.m. |
| Keyshanc — Part 1 | 1,485 | May 31, 2012, 1:36 p.m. |
| Enigma Part 2 | 1,137 | May 23, 2012, 10:52 p.m. |
| Smartcard RSA | 1,138 | May 19, 2012, 10:30 a.m. |
| Unconcealed RSA messages | 1,188 | May 17, 2012, 10:29 p.m. |
| Modified Caesar Cipher | 100 | May 3, 2012, 6:36 p.m. |
| Lattice Part 1 | 1,151 | May 1, 2012, 11:42 a.m. |
| Factorization Cipher — Part 3 | 1,224 | April 26, 2012, 9:43 a.m. |
| Number Sequence — Part 4 | 114 | April 25, 2012, 10:46 a.m. |
| ¿No Hablas Español? No problemo! | 120 | April 23, 2012, 9:28 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | April 3, 2012, 10:28 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | April 3, 2012, 9:37 a.m. |
| The Book Code: A Challenge for Bookworms | 108 | April 3, 2012, 8:49 a.m. |
| Number Sequence — Part 3 | 200 | March 31, 2012, 9:22 a.m. |
| Cracking SHA1-Hashed Passwords | 1,158 | March 27, 2012, 10:57 a.m. |
| ORYX Stream Cipher Part I | 1,142 | March 24, 2012, 10:38 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,142 | March 15, 2012, 1:39 p.m. |
| Hybrid Encryption I | 1,144 | March 15, 2012, 9:44 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,179 | March 13, 2012, 9:42 a.m. |
| RSA: Two different keys — same ciphertext | 1,185 | March 12, 2012, 9:59 a.m. |
| One-Time Pad with Flaws | 100 | March 10, 2012, 11 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | March 8, 2012, 10:26 a.m. |
| Partial Key Exposure with RSA — Part 1 | 1,362 | March 5, 2012, 4:10 p.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,143 | March 4, 2012, 8:45 p.m. |
| ECDH-Key Exchange for Beginners | 120 | Feb. 28, 2012, 9:14 a.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,144 | Feb. 25, 2012, 10:49 a.m. |
| Caesar Encryption | 100 | Feb. 24, 2012, 5:25 p.m. |
| Alice's Birthday Party (Part 2) | 1,144 | Feb. 20, 2012, 10:55 a.m. |
| Alice's Birthday Party (Part 1) | 1,145 | Feb. 11, 2012, 6:27 p.m. |
| Unusual encryption using a diophantine equation | 1,200 | Feb. 9, 2012, 1:35 p.m. |
| Kaskade-S/T — Part 1 | 100 | Jan. 30, 2012, 1:05 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,523 | Jan. 24, 2012, 10:52 a.m. |
| Grille Cipher | 101 | Jan. 17, 2012, 12:51 p.m. |
| Factorization Cipher — Part 2 | 1,294 | Jan. 16, 2012, 1:56 p.m. |
| Factorization Cipher — Part 1 | 101 | Jan. 1, 2012, 2:38 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 101 | Jan. 1, 2012, 1:58 p.m. |
| Number Sequence — Part 2 | 101 | Dec. 31, 2011, 6:20 p.m. |
| Number Sequence | 100 | Dec. 31, 2011, 6:01 p.m. |
| Original Caesar Cipher | 101 | March 19, 2011, 1:38 p.m. |
Gold2
Silver0
Bronze1
