| The Syllabary Cipher – Part 1 | 200 | Oct. 28, 2022, 2:20 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 150 | Oct. 16, 2022, 12:48 p.m. |
| Alberti Challenge — Part 1 | 200 | March 27, 2022, 1:02 p.m. |
| The T52 Sturgeon Challenge — Part 8 | 1,130 | July 26, 2021, 12:32 p.m. |
| Wheatstone Cryptograph — Part 1 | 200 | April 22, 2021, 2:01 p.m. |
| The SZ42 Challenge — Part 9 | 1,444 | Jan. 1, 2021, 11:23 a.m. |
| The SZ42 Challenge — Part 7 | 1,333 | Nov. 26, 2020, 7:24 p.m. |
| The SZ42 Challenge — Part 8 | 2,000 | Nov. 1, 2020, 12:38 a.m. |
| Find the right route — Part 1 | 200 | Oct. 27, 2020, 10:42 p.m. |
| The SZ42 Challenge — Part 6 | 2,000 | Oct. 3, 2020, 5 p.m. |
| The SZ42 Challenge — Part 5 | 2,000 | Sept. 3, 2020, 6:21 p.m. |
| The SZ42 Challenge — Part 4 | 2,000 | Aug. 30, 2020, 12:53 p.m. |
| The SZ42 Challenge — Part 3 | 2,000 | Aug. 16, 2020, 11:31 a.m. |
| The SZ42 Challenge — Part 2 | 1,485 | Aug. 15, 2020, 12:53 p.m. |
| The SZ42 Challenge — Part 1 | 1,373 | Aug. 13, 2020, 8:47 p.m. |
| Lightweight Introduction to Lattices — Part 3 | 2,000 | July 16, 2020, 2:42 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 200 | June 24, 2020, 11:27 a.m. |
| Lightweight Introduction to Lattices — Part 1 | 108 | May 28, 2020, 2:20 p.m. |
| Polyhomophonic Substitution — Part 1 | 110 | March 31, 2020, 1:37 p.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 1,444 | March 3, 2020, 6:52 p.m. |
| The T52 Sturgeon Challenge — Part 3 | 1,203 | Dec. 22, 2019, 8:03 p.m. |
| The T52 Sturgeon Challenge — Part 2 | 1,212 | Dec. 1, 2019, 10:01 p.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,211 | Nov. 25, 2019, 6:14 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | Aug. 15, 2019, 11:15 p.m. |
| Double Columnar Transposition | 100 | Aug. 15, 2019, 11:06 p.m. |
| Homophonic Encryption — Part 2 | 1,725 | May 11, 2019, 7:53 p.m. |
| Homophonic Encryption — Part 1 | 2,000 | May 5, 2019, 1:50 p.m. |
| Cryptanalysis Hacking Puzzles — Part 1 | 113 | Nov. 3, 2018, 5:33 p.m. |
| Autokey Cipher | 150 | Sept. 26, 2018, 7:27 p.m. |
| Modular Sequences | 150 | Sept. 26, 2018, 5:43 p.m. |
| Number Sequence — Part 10 | 200 | April 18, 2018, 8:29 p.m. |
| The Einstein Enigma | 2,000 | Feb. 8, 2018, 6:35 p.m. |
| ADFGVX — Part 2 | 100 | Jan. 3, 2018, 10:44 p.m. |
| ADFGVX — Part 1 | 100 | Jan. 3, 2018, 8 p.m. |
| AES ECB Wrong Encoding | 1,423 | Dec. 31, 2017, 6:15 p.m. |
| New Year's Greetings — Part 4 | 100 | Dec. 28, 2017, 3:19 p.m. |
| New Year's Greetings — Part 3 | 100 | Dec. 28, 2017, 2:17 p.m. |
| New Year's Greetings — Part 2 | 100 | Dec. 23, 2017, 9:34 p.m. |
| New Year's Greetings — Part 1 | 100 | Dec. 23, 2017, 6:54 p.m. |
| Advent Challenge — Part 3 | 2,000 | Dec. 22, 2017, 9:36 p.m. |
| Advent Challenge — Part 4 | 2,000 | Dec. 21, 2017, 11:30 p.m. |
| Advent-Challenge — Part 2 | 1,824 | Dec. 18, 2017, 4:07 p.m. |
| Advent-Challenge — Part 1 | 200 | Dec. 8, 2017, 9:06 p.m. |
| Number Sequence — Part 9 | 200 | Nov. 16, 2017, 10:27 p.m. |
| Image Noise | 200 | Nov. 21, 2015, 10:52 a.m. |
| Number Sequence — Part 8 | 200 | Sept. 14, 2015, 1:31 p.m. |
| A hidden word — Part 2 | 200 | April 16, 2015, 6:29 p.m. |
| Number Sequence — Part 7 | 200 | March 23, 2015, 11:26 p.m. |
| Number Sequence — Part 6 | 200 | March 23, 2015, 6:48 p.m. |
| M-138 — Part 2 | 1,824 | Dec. 25, 2014, 4:36 p.m. |
| M-138 — Part 1 | 200 | Dec. 24, 2014, 8:32 p.m. |
| The Last Note | 125 | Sept. 26, 2014, 1:21 p.m. |
| Heartbleed — Part 3 | 1,824 | Aug. 29, 2014, 5:50 p.m. |
| Heartbleed — Part 2 | 200 | Aug. 28, 2014, 11:31 p.m. |
| Heartbleed — Part 1 | 200 | Aug. 28, 2014, 11:03 p.m. |
| Playfair with hints about the grid | 100 | July 23, 2014, 12:37 p.m. |
| Double Column Transposition — Part 4 | 1,725 | May 22, 2014, 12:55 p.m. |
| Spanish Strip Cipher — Part 1 | 1,824 | March 29, 2014, 11:46 a.m. |
| Enigma Messages with Repeated Letters — Part 3 | 150 | March 6, 2014, 4:05 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 200 | March 5, 2014, 8:15 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 111 | Nov. 6, 2013, 8:11 p.m. |
| Trifid Cipher | 200 | Oct. 29, 2013, 12:02 p.m. |
| Playfair Encryption | 100 | Oct. 15, 2013, 7:04 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 200 | Sept. 26, 2013, 3:43 p.m. |
| Hill Cipher with Sudoku Key | 125 | Sept. 8, 2013, 3:06 p.m. |
| From Russia with Love | 200 | Sept. 4, 2013, 6:09 p.m. |
| Nils away on travel | 200 | Aug. 9, 2013, 11:14 a.m. |
| Snow White and the seven dwarfs | 200 | April 20, 2013, 1:56 p.m. |
| Reserve Hand Procedure — Part 1 | 200 | March 6, 2013, 10:27 p.m. |
| Multilingual Monoalphabetic Substitution | 125 | Feb. 2, 2013, 8:48 p.m. |
| Enigma Messages | 150 | Jan. 24, 2013, 5:16 p.m. |
| A hidden word | 200 | Jan. 6, 2013, 4:45 p.m. |
| Recycled One-Time Pad | 114 | Nov. 26, 2012, 7:16 p.m. |
| Zodiac Cipher | 100 | Oct. 11, 2012, 10:42 a.m. |
| Letter to the Templars — Part 3 | 2,000 | Oct. 9, 2012, 6:06 p.m. |
| ECDH-Key Exchange for Beginners | 100 | Oct. 6, 2012, 4:16 p.m. |
| Turing Bombe Enigma I | 100 | Oct. 5, 2012, 2:49 p.m. |
| Enigma Combinatorics | 100 | Oct. 1, 2012, 12:03 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Sept. 29, 2012, 9:25 p.m. |
| Beaver Code | 200 | Aug. 13, 2012, 8:45 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,133 | Aug. 1, 2012, 12:20 a.m. |
| Letter to the Templars — Part 2 | 200 | July 30, 2012, 8:20 p.m. |
| Letter to the Templars — Part 1 | 200 | July 16, 2012, 11:29 p.m. |
| Pigpen with a twist — Part 1 | 100 | June 2, 2012, 7:59 p.m. |
| How do you become a big cryptographer? | 200 | May 29, 2012, 9:37 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | May 27, 2012, 6:28 p.m. |
| ¿No Hablas Español? No problemo! | 105 | May 8, 2012, 9:50 p.m. |
| Molehunt (Part 2/3) | 100 | May 6, 2012, 12:11 p.m. |
| Molehunt (Part 1/3) | 100 | May 4, 2012, 7:58 p.m. |
| Kaskade-S/T — Part 1 | 100 | May 1, 2012, 12:25 a.m. |
| The Book Code: A Challenge for Bookworms | 103 | April 27, 2012, 12:05 a.m. |
| Number Sequence — Part 4 | 114 | April 25, 2012, 10:26 a.m. |
| Classical Ciphers^3 | 100 | April 24, 2012, 8:17 p.m. |
| Monoalphabetic Substitution | 100 | April 20, 2012, 10:07 p.m. |
| Modified Caesar Cipher | 100 | April 16, 2012, 1:42 p.m. |
| Grille Cipher | 101 | April 14, 2012, 5:24 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | April 14, 2012, 3:55 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | April 13, 2012, 2:44 p.m. |
| Factorization Cipher — Part 1 | 101 | April 12, 2012, 11:35 p.m. |
| Number Sequence — Part 3 | 108 | April 12, 2012, 11:18 a.m. |
| Number Sequence — Part 2 | 100 | April 11, 2012, 8:21 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | April 11, 2012, 5:38 p.m. |
| One-Time Pad with Flaws | 100 | April 11, 2012, 4:04 p.m. |
| Caesar Encryption | 100 | April 11, 2012, 10:39 a.m. |
| Original Caesar Cipher | 100 | April 10, 2012, 7:43 p.m. |
| Number Sequence | 100 | April 10, 2012, 7:28 p.m. |
Gold5
Silver7
Bronze9
