| The Hutton Cipher – Part 2 | 2,000 | June 5, 2023, 9:28 p.m. |
| The Hutton Cipher – Part 1 | 1,321 | June 5, 2023, 7:34 p.m. |
| The Syllabary Cipher – Part 2 | 1,233 | Feb. 1, 2023, 5:16 p.m. |
| The Syllabary Cipher – Part 1 | 150 | Oct. 29, 2022, 6:02 p.m. |
| Alberti Challenge — Part 1 | 200 | March 27, 2022, 6:18 p.m. |
| The SIGABA Challenge — Part 1 | 1,140 | Aug. 31, 2021, 9:40 p.m. |
| The T52 Sturgeon Challenge — Part 6 | 1,128 | Aug. 23, 2021, 8:16 p.m. |
| The T52 Sturgeon Challenge — Part 5 | 1,129 | Aug. 5, 2021, 8:35 p.m. |
| Wheatstone Cryptograph — Part 1 | 150 | April 22, 2021, 7:50 p.m. |
| Find the right route — Part 1 | 150 | Oct. 28, 2020, 7:57 p.m. |
| The Heavy T52 Sturgeon Challenge — Part 6 | 14,677 | Oct. 19, 2020, 9:11 a.m. |
| The T52 Sturgeon Challenge — Part 7 | 1,157 | Aug. 7, 2020, 8:58 p.m. |
| The Heavy T52 Sturgeon Challenge — Part 9 | 15,245 | July 22, 2020, 7:22 a.m. |
| The Heavy T52 Sturgeon Challenge — Part 7 | 16,645 | May 10, 2020, 8:53 p.m. |
| The Heavy T52 Sturgeon Challenge — Part 4 | 17,893 | April 20, 2020, 4:19 p.m. |
| Polyhomophonic Substitution — Part 1 | 200 | March 22, 2020, 8:48 p.m. |
| The T52 Sturgeon Challenge — Part 3 | 1,180 | March 8, 2020, 3:55 p.m. |
| The T52 Sturgeon Challenge — Part 12 | 1,196 | Jan. 27, 2020, 10:15 p.m. |
| The T52 Sturgeon Challenge — Part 11 | 1,197 | Jan. 26, 2020, 10:12 a.m. |
| The T52 Sturgeon Challenge — Part 10 | 1,198 | Jan. 23, 2020, 9:42 p.m. |
| The T52 Sturgeon Challenge — Part 8 | 1,198 | Jan. 22, 2020, 9:11 p.m. |
| The T52 Sturgeon Challenge — Part 2 | 1,193 | Jan. 19, 2020, 6:06 p.m. |
| The T52 Sturgeon Challenge — Part 4 | 1,201 | Dec. 28, 2019, 11:47 a.m. |
| The T52 Sturgeon Challenge — Part 9 | 1,209 | Dec. 27, 2019, 10:38 a.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,202 | Dec. 17, 2019, 9:35 p.m. |
| A Cloaked Substitution Cipher — Part 1 | 2,000 | Aug. 21, 2019, 11:36 p.m. |
| Handycipher made in love — Part 2 | 2,000 | May 22, 2019, 12:28 p.m. |
| Homophonic Encryption — Part 1 | 1,725 | May 6, 2019, 10:40 p.m. |
| Handycipher made in love — Part 1 | 2,000 | Feb. 16, 2019, 6:53 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 125 | Jan. 12, 2019, 10:07 p.m. |
| Weakened ElsieFour — Part 1 | 1,176 | Jan. 2, 2019, 9:55 a.m. |
| ElsieFour — Part 1 | 14,182 | Oct. 29, 2018, 1:09 p.m. |
| Autokey Cipher | 200 | Sept. 25, 2018, 10:32 p.m. |
| Fastest in the West | 1,233 | Sept. 16, 2018, 3:06 p.m. |
| The Einstein Enigma | 1,186 | Sept. 2, 2018, 9:58 a.m. |
| Number Sequence — Part 10 | 101 | Aug. 25, 2018, 5:48 p.m. |
| Weakened ElsieFour — Part 3 | 1,186 | April 24, 2018, 7:26 a.m. |
| Handycipher — Part 8 | 14,117 | April 4, 2018, 6:16 p.m. |
| Handycipher — Part 9 | 14,129 | March 26, 2018, 9:50 p.m. |
| Advent Challenge — Part 4 | 2,000 | Dec. 21, 2017, 7:14 p.m. |
| Advent-Challenge — Part 1 | 200 | Dec. 8, 2017, 8:27 p.m. |
| Kaskade-S/T — Part 6 (RansomKaskade Part 1) | 1,344 | July 29, 2017, 12:39 p.m. |
| Extended Handycipher — Part 4 | 14,475 | Feb. 27, 2017, 2:57 p.m. |
| Extended Handycipher — Part 5 | 14,510 | Feb. 13, 2017, 10:37 p.m. |
| Handycipher — Part 5 | 15,043 | Oct. 14, 2016, 1:50 p.m. |
| Handycipher — Part 6 | 15,124 | Oct. 3, 2016, 10:57 a.m. |
| Weakened Handycipher — Part 6 | 1,292 | Aug. 14, 2016, 5:29 p.m. |
| Weakened Handycipher — Part 5 | 1,337 | July 28, 2016, 4:36 p.m. |
| Weakened Handycipher — Part 4 | 1,414 | July 13, 2016, 9:09 p.m. |
| New Year's Greetings — Part 4 | 150 | March 22, 2016, 10:21 a.m. |
| New Year's Greetings — Part 3 | 150 | March 22, 2016, 10:04 a.m. |
| New Year's Greetings — Part 2 | 200 | March 21, 2016, 10:09 p.m. |
| New Year's Greetings — Part 1 | 200 | March 21, 2016, 9:28 p.m. |
| Kaskade-S/T — Part 5 | 1,102 | Dec. 12, 2015, 3:40 p.m. |
| Image Noise | 200 | Nov. 21, 2015, 8:20 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Nov. 14, 2015, 7:37 p.m. |
| News from Castle Mansfeld | 150 | Nov. 14, 2015, 1:08 p.m. |
| Extended Handycipher — Part 3 | 1,183 | Oct. 31, 2015, 6:28 p.m. |
| Extended Handycipher — Part 2 | 1,185 | Oct. 23, 2015, 9:07 a.m. |
| Extended Handycipher — Part 1 | 1,192 | Sept. 27, 2015, 11:51 a.m. |
| Handycipher — Part 3 | 14,592 | Sept. 23, 2015, 7:08 p.m. |
| Handycipher — Part 2 | 1,187 | Sept. 20, 2015, 1:16 p.m. |
| Handycipher — Part 1 | 1,188 | Sept. 19, 2015, 9:09 p.m. |
| Weakened Handycipher — Part 3 | 1,216 | Sept. 14, 2015, 6:54 p.m. |
| Number Sequence — Part 8 | 200 | Sept. 14, 2015, 3:22 p.m. |
| Weakened Handycipher — Part 2 | 1,220 | Sept. 8, 2015, 5:32 a.m. |
| Weakened Handycipher — Part 1 | 1,235 | Aug. 15, 2015, 4:25 p.m. |
| A hidden word — Part 2 | 200 | April 17, 2015, 8:04 a.m. |
| M-138 — Part 4 | 1,367 | Jan. 15, 2015, 9:25 p.m. |
| Factorization Cipher — Part 2 | 1,114 | Jan. 9, 2015, 7:42 p.m. |
| M-138 — Part 3 | 1,660 | Dec. 27, 2014, 8:15 a.m. |
| M-138 — Part 2 | 2,000 | Dec. 24, 2014, 9:58 p.m. |
| M-138 — Part 1 | 200 | Dec. 24, 2014, 8:14 p.m. |
| Factorization Cipher — Part 3 | 1,117 | Nov. 1, 2014, 9:14 p.m. |
| The Last Note | 150 | Sept. 23, 2014, 10:59 p.m. |
| Double Column Transposition — Part 3 | 1,288 | June 19, 2014, 5:41 p.m. |
| Double Column Transposition — Part 2 | 1,315 | June 7, 2014, 3:09 p.m. |
| Double Column Transposition — Part 4 | 1,576 | May 25, 2014, 3:35 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 120 | March 9, 2014, 5:27 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 150 | March 6, 2014, 5:21 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 150 | March 6, 2014, 4:14 p.m. |
| Classical Ciphers^3 | 100 | Feb. 5, 2014, 4:38 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Dec. 5, 2013, 4:58 p.m. |
| Turing Bombe Enigma I | 100 | Dec. 5, 2013, 4:36 p.m. |
| Enigma Part 2 | 1,114 | Nov. 27, 2013, 8:29 p.m. |
| Enigma Part 1 | 1,114 | Nov. 8, 2013, 4:13 p.m. |
| Enigma Messages | 100 | Nov. 1, 2013, 6:14 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 133 | Oct. 31, 2013, 4:18 p.m. |
| Trifid Cipher | 200 | Oct. 29, 2013, 5:20 p.m. |
| Playfair with hints about the grid | 100 | Oct. 2, 2013, 5:18 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 200 | Sept. 26, 2013, 9:53 p.m. |
| Hill Cipher with Sudoku Key | 114 | Sept. 10, 2013, 4:36 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Sept. 8, 2013, 9:45 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Sept. 8, 2013, 9:34 a.m. |
| From Russia with Love | 150 | Sept. 5, 2013, 4:19 p.m. |
| Nils away on travel | 150 | Aug. 9, 2013, 1:07 p.m. |
| Multilingual Monoalphabetic Substitution | 101 | May 22, 2013, 9:34 p.m. |
| Snow White and the seven dwarfs | 114 | April 26, 2013, 4:02 p.m. |
| Cascading Encryption — Part 1/3 | 101 | April 3, 2013, 4:26 p.m. |
| A hidden word | 200 | Jan. 6, 2013, 6:32 p.m. |
| Strange Message from Thessaloniki | 111 | Dec. 18, 2012, 5:37 p.m. |
| Recycled One-Time Pad | 111 | Nov. 28, 2012, 4:48 p.m. |
| Playfair Encryption | 100 | Nov. 14, 2012, 5:33 p.m. |
| Letter to the Templars — Part 3 | 2,000 | Oct. 9, 2012, 9:52 p.m. |
| Kaskade-S/T — Part 3 | 1,141 | Aug. 21, 2012, 4:40 p.m. |
| Kaskade-S/T — Part 2 | 1,141 | Aug. 18, 2012, 3:02 p.m. |
| Kaskade-S/T — Part 1 | 100 | Aug. 14, 2012, 9:12 p.m. |
| Beaver Code | 150 | Aug. 14, 2012, 9:03 p.m. |
| Letter to the Templars — Part 2 | 200 | July 30, 2012, 9:43 p.m. |
| Letter to the Templars — Part 1 | 150 | July 18, 2012, 4:36 p.m. |
| How do you become a big cryptographer? | 200 | May 29, 2012, 4:50 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,196 | May 28, 2012, 9:55 a.m. |
| ¿No Hablas Español? No problemo! | 103 | May 21, 2012, 7:22 p.m. |
| Number Sequence — Part 4 | 113 | April 25, 2012, 7:56 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 101 | April 22, 2012, 9:46 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 101 | April 18, 2012, 4:27 p.m. |
| Number Sequence — Part 3 | 150 | April 1, 2012, 6:19 p.m. |
| An Invisible Message | 102 | Nov. 30, 2011, 3:14 p.m. |
| Factorization Cipher — Part 1 | 200 | Oct. 17, 2011, 8:55 p.m. |
| Grille Cipher | 150 | Oct. 15, 2011, 9:34 p.m. |
| Double Columnar Transposition | 200 | Oct. 12, 2011, 9:53 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 200 | Sept. 9, 2011, 8:04 p.m. |
| Pigpen with a twist — Part 1 | 200 | Sept. 5, 2011, 10:17 p.m. |
| Modified Caesar Cipher | 200 | Sept. 2, 2011, 8:39 p.m. |
| Molehunt (Part 3/3) | 1,164 | Sept. 1, 2011, 4:37 p.m. |
| Molehunt (Part 2/3) | 100 | Sept. 1, 2011, 4:36 p.m. |
| Molehunt (Part 1/3) | 100 | Aug. 28, 2011, 9:13 a.m. |
| ADFGVX — Part 2 | 114 | Aug. 22, 2011, 5:06 p.m. |
| ADFGVX — Part 1 | 114 | Aug. 21, 2011, 6 p.m. |
| Number Sequence — Part 2 | 133 | July 13, 2011, 4:34 p.m. |
| Original Caesar Cipher | 125 | Dec. 18, 2010, 8:42 a.m. |
| Monoalphabetic Substitution | 102 | Dec. 1, 2010, 9:50 p.m. |
| Caesar Encryption | 103 | Nov. 19, 2010, 8:38 p.m. |
| One-Time Pad with Flaws | 150 | Nov. 14, 2010, 10:07 a.m. |
| Number Sequence | 133 | Oct. 16, 2010, 4:28 p.m. |