| Monoalphabetic substitution with camouflage — Part 2 | 1,089 | June 24, 2019, 11:10 p.m. |
| Handycipher made in love — Part 2 | 1,324 | June 23, 2019, 5:55 p.m. |
| Handycipher made in love — Part 1 | 1,216 | June 19, 2019, 5:29 p.m. |
| Homophonic Encryption — Part 4 | 1,613 | May 13, 2019, 7:52 p.m. |
| Homophonic Encryption — Part 3 | 1,613 | May 13, 2019, 7:39 p.m. |
| Homophonic Encryption — Part 2 | 1,613 | May 13, 2019, 7:28 p.m. |
| Homophonic Encryption — Part 1 | 1,824 | May 6, 2019, 2:05 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,261 | April 23, 2019, 5:55 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 107 | Jan. 22, 2019, 9:08 p.m. |
| Modular Sequences | 102 | Nov. 19, 2018, 9:26 p.m. |
| Cryptanalysis Hacking Puzzles — Part 1 | 150 | Oct. 28, 2018, 6:58 p.m. |
| Breaking a Filter Generator | 1,385 | Oct. 15, 2018, 1:04 p.m. |
| Autokey Cipher | 125 | Sept. 28, 2018, 4:50 p.m. |
| Trendy Messenger | 1,456 | June 23, 2018, 2:51 p.m. |
| Fastest in the West | 1,576 | June 17, 2018, 10:53 p.m. |
| Summer Job | 2,000 | June 12, 2018, 9:48 p.m. |
| Number Sequence — Part 10 | 117 | April 23, 2018, 5:22 p.m. |
| Unconcealed RSA messages | 1,094 | March 12, 2018, 12:50 p.m. |
| Unusual encryption using a diophantine equation | 1,093 | Feb. 18, 2018, 9:08 p.m. |
| The Einstein Enigma | 1,660 | Feb. 11, 2018, 5:34 p.m. |
| Advent Challenge — Part 4 | 1,423 | Jan. 4, 2018, 6:37 p.m. |
| Advent Challenge — Part 3 | 1,456 | Jan. 3, 2018, 5:42 p.m. |
| Advent-Challenge — Part 2 | 1,406 | Jan. 2, 2018, 6:16 p.m. |
| Advent-Challenge — Part 1 | 114 | Dec. 15, 2017, 4:27 p.m. |
| Number Sequence — Part 9 | 120 | Nov. 21, 2017, 12:55 p.m. |
| New Year's Greetings — Part 5 | 1,212 | Aug. 1, 2016, 6:43 a.m. |
| New Year's Greetings — Part 4 | 101 | July 21, 2016, 6:12 p.m. |
| New Year's Greetings — Part 3 | 101 | July 21, 2016, 5:38 p.m. |
| New Year's Greetings — Part 2 | 101 | July 21, 2016, 1:13 p.m. |
| New Year's Greetings — Part 1 | 101 | July 21, 2016, 12:57 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,105 | March 12, 2016, 9:56 p.m. |
| Enigma Combinatorics | 100 | March 6, 2016, 2:07 p.m. |
| Double Column Transposition — Part 4 | 1,137 | Jan. 5, 2016, 9:36 p.m. |
| Image Noise | 150 | Nov. 22, 2015, 9:56 a.m. |
| Weakened Granit — Part 1 | 110 | Oct. 3, 2015, 8:13 p.m. |
| Number Sequence — Part 8 | 200 | Sept. 14, 2015, 7 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Sept. 11, 2015, 4:29 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | July 19, 2015, 5:04 a.m. |
| ORYX Stream Cipher — Part 3 (revised) | 1,127 | July 14, 2015, 12:08 p.m. |
| ORYX Stream Cipher Part II | 1,102 | June 23, 2015, 9:07 p.m. |
| ORYX Stream Cipher Part I | 1,102 | June 23, 2015, 7:14 p.m. |
| Number Sequence — Part 7 | 102 | May 8, 2015, 3:35 p.m. |
| A hidden word — Part 2 | 200 | April 16, 2015, 9:27 p.m. |
| M-138 — Part 4 | 1,228 | April 6, 2015, 9:11 a.m. |
| Number Sequence — Part 6 | 200 | March 23, 2015, 8:05 p.m. |
| M-138 — Part 3 | 1,406 | Jan. 9, 2015, 4:57 p.m. |
| M-138 — Part 2 | 1,725 | Dec. 26, 2014, 9:27 p.m. |
| M-138 — Part 1 | 133 | Dec. 26, 2014, 6:05 p.m. |
| The Last Note | 150 | Sept. 24, 2014, 1:02 p.m. |
| Heartbleed — Part 2 | 113 | Sept. 4, 2014, 8:06 p.m. |
| Heartbleed — Part 1 | 117 | Sept. 2, 2014, 6:42 p.m. |
| Double Column Transposition — Part 2 | 1,290 | June 18, 2014, 11:03 p.m. |
| Spanish Strip Cipher — Part 2 | 1,725 | March 29, 2014, 8:08 p.m. |
| Ku Klux Klan | 1,000 | March 10, 2014, 8:57 a.m. |
| Enigma Messages with Repeated Letters — Part 4 | 150 | March 6, 2014, 10:29 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 200 | March 5, 2014, 10:07 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 200 | March 5, 2014, 9:21 p.m. |
| Typex — Part 2 | 1,175 | Dec. 12, 2013, 7:08 p.m. |
| Typex — Part 1 | 1,170 | Dec. 3, 2013, 6:37 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 114 | Nov. 4, 2013, 6:07 p.m. |
| Trifid Cipher | 200 | Oct. 29, 2013, 5:44 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 200 | Sept. 26, 2013, 10:25 p.m. |
| Hill Cipher with Sudoku Key | 200 | Sept. 5, 2013, 12:53 p.m. |
| From Russia with Love | 200 | Sept. 4, 2013, 6:39 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Sept. 3, 2013, 6:15 p.m. |
| Keyshanc — Part 2 | 1,149 | Aug. 9, 2013, 11:42 p.m. |
| Nils away on travel | 200 | Aug. 9, 2013, 12:15 p.m. |
| Keyshanc — Part 1 | 1,149 | Aug. 7, 2013, 11:46 p.m. |
| Pigpen with a twist — Part 3 | 1,131 | July 30, 2013, 10:29 p.m. |
| Pigpen with a twist — Part 2 | 1,131 | July 30, 2013, 9:02 p.m. |
| Kaskade-S/T — Part 3 | 1,124 | July 5, 2013, 8:58 p.m. |
| Kaskade-S/T — Part 2 | 1,124 | July 3, 2013, 1:14 p.m. |
| Turing Bombe Enigma I | 100 | June 25, 2013, 10:42 p.m. |
| Double Columnar Transposition | 100 | June 15, 2013, 6:54 a.m. |
| Monoalphabetic Substitution | 100 | June 13, 2013, 11:26 a.m. |
| Kaskade-S/T — Part 1 | 100 | May 24, 2013, 8:59 p.m. |
| Enigma Part 2 | 1,120 | May 23, 2013, 9:04 p.m. |
| ADFGVX — Part 2 | 100 | May 22, 2013, 8:54 p.m. |
| ADFGVX — Part 1 | 100 | May 15, 2013, 10:24 p.m. |
| Snow White and the seven dwarfs | 133 | April 22, 2013, 10:01 p.m. |
| Molehunt (Part 3/3) | 1,122 | April 11, 2013, 6:05 p.m. |
| Molehunt (Part 2/3) | 100 | April 4, 2013, 1 p.m. |
| Reserve Hand Procedure — Part 1 | 150 | March 8, 2013, 5:46 p.m. |
| Multilingual Monoalphabetic Substitution | 200 | Jan. 30, 2013, 5:43 p.m. |
| Molehunt (Part 1/3) | 100 | Jan. 30, 2013, 1:04 p.m. |
| Cascading Encryption — Part 1/3 | 200 | Jan. 26, 2013, 1:32 p.m. |
| Enigma Messages | 200 | Jan. 23, 2013, 8:02 p.m. |
| Playfair with hints about the grid | 200 | Jan. 17, 2013, 8:50 a.m. |
| A hidden word | 150 | Jan. 7, 2013, 5:54 p.m. |
| Enigma Part 1 | 1,127 | Dec. 5, 2012, 9:31 p.m. |
| Recycled One-Time Pad | 108 | Dec. 2, 2012, 11:57 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,128 | Nov. 12, 2012, 7:17 p.m. |
| Factorization Cipher — Part 3 | 1,165 | Nov. 8, 2012, 10:33 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,168 | Nov. 1, 2012, 10:09 p.m. |
| Hybrid Encryption I | 1,129 | Oct. 30, 2012, 8 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,128 | Oct. 29, 2012, 6:45 p.m. |
| RSA: Two different keys — same ciphertext | 1,149 | Oct. 27, 2012, 5:23 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,147 | Oct. 26, 2012, 10:30 p.m. |
| Alice's Birthday Party (Part 2) | 1,128 | Oct. 25, 2012, 8:53 p.m. |
| Alice's Birthday Party (Part 1) | 1,128 | Oct. 25, 2012, 7:03 p.m. |
| BCR code (Book-Caesar-RSA) | 1,310 | Oct. 20, 2012, 11:12 p.m. |
| Letter to the Templars — Part 3 | 1,660 | Oct. 13, 2012, 8:59 a.m. |
| Concealed Messages — Vigenère's Night Sky | 1,199 | Oct. 12, 2012, 10:20 p.m. |
| One-Time Pad with Flaws | 100 | Oct. 1, 2012, 10:21 p.m. |
| Pigpen with a twist — Part 1 | 100 | Sept. 30, 2012, 12:38 p.m. |
| Playfair Encryption | 100 | Sept. 27, 2012, 7:44 p.m. |
| An 'unhearable' message | 101 | Sept. 27, 2012, 5:51 p.m. |
| How do you become a big cryptographer? | 101 | Sept. 24, 2012, 1:22 p.m. |
| A really long number sequence | 1,157 | Sept. 5, 2012, 5:34 p.m. |
| Number Sequence — Part 5 | 101 | Sept. 1, 2012, 12:32 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Aug. 27, 2012, 12:34 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Aug. 27, 2012, 8:22 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Aug. 25, 2012, 9:08 a.m. |
| Beaver Code | 200 | Aug. 13, 2012, 11:17 p.m. |
| Classical Ciphers^3 | 100 | Aug. 4, 2012, 2:26 p.m. |
| Letter to the Templars — Part 2 | 200 | July 31, 2012, 1:13 p.m. |
| Zodiac Cipher | 100 | July 31, 2012, 1:04 p.m. |
| An Invisible Message | 100 | July 23, 2012, 6:22 p.m. |
| Letter to the Templars — Part 1 | 150 | July 18, 2012, 6:12 p.m. |
| ECDH-Key Exchange for Beginners | 101 | May 24, 2012, 1:27 p.m. |
| Number Sequence — Part 4 | 114 | April 24, 2012, 8:50 p.m. |
| ¿No Hablas Español? No problemo! | 125 | April 22, 2012, 6:33 p.m. |
| The Book Code: A Challenge for Bookworms | 104 | April 12, 2012, 6:31 p.m. |
| Grille Cipher | 101 | April 6, 2012, 10:47 p.m. |
| Number Sequence — Part 3 | 117 | April 5, 2012, 5:46 p.m. |
| Cracking SHA1-Hashed Passwords | 1,158 | March 26, 2012, 12:51 p.m. |
| Modified Caesar Cipher | 101 | March 8, 2012, 9:03 p.m. |
| Factorization Cipher — Part 2 | 1,235 | March 5, 2012, 12:56 p.m. |
| Caesar Encryption | 100 | Feb. 16, 2012, 5:11 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 101 | Feb. 16, 2012, 4:09 p.m. |
| Original Caesar Cipher | 100 | Feb. 15, 2012, 10:31 p.m. |
| Factorization Cipher — Part 1 | 101 | Feb. 15, 2012, 7:14 p.m. |
| Number Sequence — Part 2 | 100 | Feb. 15, 2012, 6:48 p.m. |
| Number Sequence | 100 | Feb. 15, 2012, 6:31 p.m. |
Gold1
Silver2
Bronze1
