| A disguised code | 200 | Oct. 31, 2023, 4:17 p.m. |
| The Hutton Cipher – Part 4 | 1,824 | Sept. 7, 2023, 7:18 p.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,080 | Aug. 19, 2023, 5:16 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,079 | Aug. 19, 2023, 5:03 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,079 | Aug. 18, 2023, 5:26 p.m. |
| Hybrid Encryption I | 1,078 | Aug. 11, 2023, 6:18 p.m. |
| The Hutton Cipher – Part 3 | 1,613 | July 25, 2023, 12:50 p.m. |
| The Hutton Cipher – Part 2 | 2,000 | June 6, 2023, 3:17 a.m. |
| The Josse Challenge – Part 3 | 1,272 | May 24, 2023, 1:54 p.m. |
| The Hutton Cipher – Part 1 | 1,660 | May 6, 2023, 7:29 a.m. |
| The Josse Challenge – Part 2 | 2,000 | Feb. 25, 2023, 11:19 a.m. |
| The Josse Challenge – Part 1 | 2,000 | Feb. 10, 2023, 8:21 p.m. |
| A Cloaked Substitution Cipher — Part 2 | 1,111 | Feb. 8, 2023, 12:36 p.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,111 | Feb. 7, 2023, 9:24 p.m. |
| The SZ42 Challenge — Part 12 | 1,146 | Jan. 22, 2023, 4:59 p.m. |
| Turing Bombe Enigma I | 100 | Jan. 15, 2023, 12:41 p.m. |
| Modified Vigenère Cipher | 1,158 | Jan. 14, 2023, 6:30 p.m. |
| Merkle-Hellman Knapsack Challenge — Part 2 | 1,270 | Dec. 12, 2022, 5:38 p.m. |
| Alberti Challenge — Part 2 | 1,191 | Nov. 18, 2022, 5:28 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 103 | Nov. 14, 2022, 12:48 p.m. |
| The Syllabary Cipher – Part 4 | 1,414 | Nov. 12, 2022, 5:04 p.m. |
| Hill Cipher | 1,261 | Nov. 9, 2022, 9:15 p.m. |
| Alberti Challenge — Part 1 | 100 | Nov. 4, 2022, 7:12 p.m. |
| The Syllabary Cipher – Part 5 | 1,547 | Nov. 4, 2022, 10:35 a.m. |
| The Syllabary Cipher – Part 3 | 1,660 | Nov. 1, 2022, 12:18 p.m. |
| The Syllabary Cipher – Part 2 | 1,660 | Oct. 31, 2022, 5:41 p.m. |
| The Syllabary Cipher – Part 1 | 125 | Oct. 31, 2022, 4:09 p.m. |
| The SZ42 Challenge — Part 9 | 1,148 | March 18, 2022, 6:03 p.m. |
| The SZ42 Challenge — Part 8 | 1,145 | Feb. 24, 2022, 11:38 a.m. |
| The SZ42 Challenge — Part 7 | 1,145 | Feb. 24, 2022, 11:08 a.m. |
| The SZ42 Challenge — Part 6 | 1,143 | Feb. 23, 2022, 5:27 p.m. |
| The SZ42 Challenge — Part 5 | 1,141 | Feb. 22, 2022, 6:04 p.m. |
| The SZ42 Challenge — Part 4 | 1,140 | Feb. 22, 2022, 5:43 p.m. |
| The SZ42 Challenge — Part 3 | 1,140 | Feb. 15, 2022, 9:19 a.m. |
| The SZ42 Challenge — Part 2 | 1,139 | Feb. 13, 2022, 7:45 p.m. |
| The SZ42 Challenge — Part 1 | 1,138 | Feb. 13, 2022, 4:17 p.m. |
| Cipher ID — Part 1 | 1,129 | Nov. 28, 2021, 5:24 p.m. |
| Zodiac Cipher | 100 | Nov. 3, 2021, 12:02 p.m. |
| ADFGVX — Part 2 | 100 | Nov. 2, 2021, 7:11 p.m. |
| ADFGVX — Part 1 | 100 | Nov. 2, 2021, 6:29 p.m. |
| Wheatstone Cryptograph — Part 2 | 1,198 | Nov. 2, 2021, 3:52 p.m. |
| Wheatstone Cryptograph — Part 1 | 101 | Nov. 1, 2021, 12:04 p.m. |
| Double Column Transposition — Part 1 | 1,092 | Feb. 2, 2021, 11:22 a.m. |
| Double Column Transposition — Part 2 | 1,092 | Jan. 16, 2021, 11:33 a.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,131 | Jan. 15, 2021, 4:45 p.m. |
| Double Column Transposition — Part 4 | 1,092 | Jan. 15, 2021, 3:20 p.m. |
| Polyhomophonic Substitution — Part 3 | 1,433 | April 20, 2020, 11:01 a.m. |
| Homophonic Encryption — Part 4 | 1,162 | March 31, 2020, 6:24 p.m. |
| Homophonic Encryption — Part 3 | 1,162 | March 31, 2020, 5:34 p.m. |
| Homophonic Encryption — Part 2 | 1,162 | March 30, 2020, 7:13 p.m. |
| Homophonic Encryption — Part 1 | 1,162 | March 29, 2020, 5:10 p.m. |
| Autokey Cipher | 100 | March 29, 2020, 3:53 p.m. |
| Polyhomophonic Substitution — Part 2 | 2,000 | March 29, 2020, noon |
| Polyhomophonic Substitution — Part 1 | 117 | March 27, 2020, 10:42 a.m. |
| Enigma Messages | 100 | Aug. 16, 2019, 12:40 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | Aug. 10, 2019, 5:49 p.m. |
| Cryptanalysis Hacking Puzzles — Part 1 | 100 | Aug. 10, 2019, 5:08 p.m. |
| Advent Challenge — Part 4 | 1,824 | Dec. 23, 2017, 9:15 a.m. |
| Advent-Challenge — Part 2 | 1,660 | Dec. 20, 2017, 3:48 p.m. |
| Advent-Challenge — Part 1 | 109 | Dec. 19, 2017, 11:02 a.m. |
| Kaskade-S/T — Part 3 | 1,093 | Sept. 19, 2017, 2:29 p.m. |
| Image Noise | 100 | Sept. 12, 2017, 7:16 p.m. |
| Kaskade-S/T — Part 2 | 1,093 | Sept. 11, 2017, 11:07 a.m. |
| Kaskade-S/T — Part 1 | 100 | Sept. 10, 2017, 4:37 p.m. |
| M-138 — Part 3 | 1,128 | Jan. 20, 2017, 9:22 a.m. |
| Spirale — Part 3 | 1,143 | Jan. 19, 2017, 3:27 p.m. |
| Spirale — Part 2 | 1,143 | Jan. 19, 2017, 3:23 p.m. |
| Spirale — Part 1 | 1,143 | Jan. 19, 2017, 3:14 p.m. |
| M-138 — Part 2 | 1,128 | Jan. 18, 2017, 11:36 a.m. |
| M-138 — Part 1 | 100 | Jan. 17, 2017, 7:43 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | July 25, 2016, 11:05 a.m. |
| Number Sequence — Part 8 | 100 | July 24, 2016, 5:46 p.m. |
| Number Sequence — Part 6 | 100 | July 24, 2016, 5:15 p.m. |
| Number Sequence — Part 4 | 100 | July 23, 2016, 7:43 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | July 23, 2016, 7:27 p.m. |
| Number Sequence — Part 3 | 100 | July 23, 2016, 4:12 p.m. |
| Number Sequence — Part 2 | 100 | July 23, 2016, 4:06 p.m. |
| Number Sequence | 100 | July 22, 2016, 11:14 a.m. |
| ¿No Hablas Español? No problemo! | 100 | July 20, 2016, 10:53 a.m. |
| Double Column Transposition — Part 3 | 1,125 | July 19, 2016, 6:50 p.m. |
| The Last Note | 100 | July 19, 2016, 3:53 p.m. |
| Cascading Encryption — Part 1/3 | 100 | July 18, 2016, 4:52 p.m. |
| Recycled One-Time Pad | 100 | July 18, 2016, 12:33 p.m. |
| Molehunt (Part 3/3) | 1,096 | July 17, 2016, 8:58 a.m. |
| Molehunt (Part 2/3) | 100 | July 16, 2016, 4:02 p.m. |
| Molehunt (Part 1/3) | 100 | July 16, 2016, 12:48 p.m. |
| Trifid Cipher | 100 | July 10, 2016, 5:33 p.m. |
| Nils away on travel | 100 | July 10, 2016, 10:07 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Oct. 22, 2015, 2:17 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | Oct. 22, 2015, 2:06 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Oct. 22, 2015, 11:15 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | Oct. 22, 2015, 10:43 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Oct. 22, 2015, 10 a.m. |
| Enigma Part 2 | 1,100 | Oct. 17, 2015, 4:23 p.m. |
| Enigma Part 1 | 1,100 | Oct. 10, 2015, 2:36 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,100 | Oct. 7, 2015, 3:59 p.m. |
| Monoalphabetic Substitution | 100 | Oct. 6, 2015, 3:11 p.m. |
| From Russia with Love | 100 | Oct. 5, 2015, 4:10 p.m. |
| Snow White and the seven dwarfs | 100 | Oct. 4, 2015, 4:40 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Oct. 4, 2015, 3:54 p.m. |
| One-Time Pad with Flaws | 100 | Oct. 4, 2015, 2:37 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | Oct. 4, 2015, 9:54 a.m. |
| Modified Caesar Cipher | 100 | Oct. 3, 2015, 4:21 p.m. |
| Grille Cipher | 100 | Oct. 3, 2015, 7:22 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Sept. 30, 2015, 2:23 p.m. |
| Caesar Encryption | 100 | Sept. 29, 2015, 8:40 a.m. |
| Beaver Code | 100 | Sept. 29, 2015, 8:06 a.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,101 | July 29, 2015, 4:59 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,106 | July 29, 2015, 3:11 p.m. |
| Alice's Birthday Party (Part 2) | 1,101 | July 29, 2015, 2:06 p.m. |
| Alice's Birthday Party (Part 1) | 1,101 | July 29, 2015, 10:31 a.m. |
| Playfair with hints about the grid | 100 | July 28, 2015, 1:14 p.m. |
| Playfair Encryption | 100 | July 28, 2015, 8:41 a.m. |
| Double Columnar Transposition | 100 | July 27, 2015, 8:13 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | July 17, 2015, 12:21 p.m. |
| Pigpen with a twist — Part 1 | 100 | July 16, 2015, 4:58 p.m. |
| Cracking SHA1-Hashed Passwords | 1,104 | July 16, 2015, 3:22 p.m. |
| Factorization Cipher — Part 2 | 1,109 | July 16, 2015, 12:26 p.m. |
| Factorization Cipher — Part 1 | 100 | July 15, 2015, 12:52 p.m. |
| Letter to the Templars — Part 3 | 1,118 | July 15, 2015, 11:45 a.m. |
| Letter to the Templars — Part 2 | 100 | July 15, 2015, 11:13 a.m. |
| Letter to the Templars — Part 1 | 100 | July 14, 2015, 8:35 p.m. |
| Original Caesar Cipher | 100 | July 14, 2015, 3:20 p.m. |
Gold1
Silver7
Bronze1
