| Merkle-Hellman Knapsack Challenge - Part 1 | 102 | Dec. 12, 2022, 3:02 p.m. |
| The Syllabary Cipher – Part 4 | 1,300 | Dec. 10, 2022, 11:30 a.m. |
| The Syllabary Cipher – Part 5 | 1,367 | Nov. 19, 2022, 2:31 p.m. |
| The Syllabary Cipher – Part 3 | 1,373 | Nov. 18, 2022, 8:34 p.m. |
| The Syllabary Cipher – Part 1 | 105 | Nov. 17, 2022, 4:56 p.m. |
| The Syllabary Cipher – Part 2 | 1,378 | Nov. 17, 2022, 4:55 p.m. |
| Polyhomophonic Substitution — Part 3 | 1,129 | April 5, 2022, 9:26 p.m. |
| Alberti Challenge — Part 1 | 117 | April 1, 2022, 3:43 p.m. |
| Number Sequence — Part 5 | 100 | March 6, 2022, 11:59 a.m. |
| Modified Vigenère Cipher | 1,349 | Feb. 19, 2022, 10:05 p.m. |
| Cascading Encryption — Part 2/3 | 1,086 | Dec. 27, 2021, 12:02 p.m. |
| Pigpen with a twist — Part 3 | 1,082 | Nov. 8, 2021, 10:36 a.m. |
| Pigpen with a twist — Part 2 | 1,082 | Nov. 7, 2021, 2:36 p.m. |
| Keyshanc — Part 2 | 1,084 | Sept. 16, 2021, 11:38 a.m. |
| Keyshanc — Part 1 | 1,084 | Sept. 15, 2021, 8:15 p.m. |
| BCR code (Book-Caesar-RSA) | 1,085 | Aug. 2, 2021, 8:25 p.m. |
| Wheatstone Cryptograph — Part 2 | 1,324 | June 23, 2021, 3:32 p.m. |
| Wheatstone Cryptograph — Part 1 | 103 | May 26, 2021, 8:21 p.m. |
| M-138 — Part 4 | 1,095 | Feb. 17, 2021, 2:02 p.m. |
| Kaskade-S/T — Part 3 | 1,083 | Jan. 26, 2021, 8:42 p.m. |
| Find the right route — Part 3 | 108 | Jan. 8, 2021, 3:35 p.m. |
| Kaskade-S/T — Part 2 | 1,083 | Jan. 7, 2021, 11:18 a.m. |
| Find the right route — Part 2 | 107 | Jan. 3, 2021, 10:33 a.m. |
| An Invisible Message | 100 | Dec. 22, 2020, 1:37 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,082 | Dec. 18, 2020, 8:34 p.m. |
| Find the right route — Part 1 | 200 | Oct. 28, 2020, 10:18 a.m. |
| Music Code — Part 2 | 1,084 | Oct. 26, 2020, 1:54 p.m. |
| Music Code — Part 1 | 100 | Oct. 26, 2020, 1:33 p.m. |
| Modular Sequences | 100 | Oct. 26, 2020, 9:19 a.m. |
| Double Column Transposition — Part 4 | 1,094 | Sept. 27, 2020, 2:06 p.m. |
| M-138 — Part 3 | 1,096 | Sept. 12, 2020, 1:52 p.m. |
| M-138 — Part 2 | 1,096 | Sept. 6, 2020, 7:31 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 102 | Aug. 28, 2020, 9:38 a.m. |
| Weakened Granit — Part 1 | 100 | Aug. 9, 2020, 6:27 p.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,087 | July 1, 2020, 1:05 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | June 6, 2020, 11:13 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | May 25, 2020, 9:12 a.m. |
| Lightweight Introduction to Lattices — Part 1 | 120 | May 20, 2020, 8:02 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,087 | April 27, 2020, 3:35 p.m. |
| Number Sequence — Part 6 | 100 | April 4, 2020, 9 p.m. |
| Polyhomophonic Substitution — Part 2 | 1,824 | March 29, 2020, 9:05 p.m. |
| Polyhomophonic Substitution — Part 1 | 150 | March 23, 2020, 3:05 p.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 1,327 | March 23, 2020, 8:49 a.m. |
| Alice's Birthday Party (Part 1) | 1,084 | March 7, 2020, 2:41 p.m. |
| Cipher ID — Part 1 | 1,248 | Feb. 6, 2020, 10:29 a.m. |
| Polyphonic Substitution Cipher — Part 2 | 1,523 | Jan. 22, 2020, 11:31 a.m. |
| Recycled One-Time Pad | 100 | Nov. 26, 2019, 3:29 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 2,000 | Nov. 22, 2019, 10:56 a.m. |
| A Cloaked Substitution Cipher — Part 2 | 1,523 | Sept. 2, 2019, 1:12 p.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,523 | Aug. 28, 2019, 12:59 p.m. |
| Spanish Strip Cipher — Part 2 | 1,098 | Aug. 2, 2019, 2:46 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,089 | June 29, 2019, 1:57 p.m. |
| Zodiac Cipher | 100 | June 16, 2019, 3:34 p.m. |
| Homophonic Encryption — Part 4 | 1,321 | June 12, 2019, 2:03 p.m. |
| Spanish Strip Cipher — Part 1 | 1,099 | June 11, 2019, 1:43 p.m. |
| Homophonic Encryption — Part 3 | 1,444 | May 21, 2019, 10:23 a.m. |
| Homophonic Encryption — Part 2 | 1,485 | May 18, 2019, 7:57 p.m. |
| Homophonic Encryption — Part 1 | 1,523 | May 12, 2019, 10:44 a.m. |
| Handycipher made in love — Part 1 | 1,281 | April 10, 2019, 10:11 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | March 7, 2019, 8:59 a.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,613 | Feb. 20, 2019, 3:14 p.m. |
| Double Columnar Transposition | 100 | Feb. 2, 2019, 9:27 p.m. |
| Hill Cipher with Sudoku Key | 100 | Jan. 30, 2019, 6:38 p.m. |
| New Year's Greetings — Part 4 | 100 | Jan. 25, 2019, 7:50 p.m. |
| New Year's Greetings — Part 3 | 100 | Jan. 24, 2019, 8:15 p.m. |
| New Year's Greetings — Part 2 | 100 | Jan. 24, 2019, 6:39 p.m. |
| New Year's Greetings — Part 1 | 100 | Jan. 24, 2019, 6:31 p.m. |
| A hidden word — Part 2 | 100 | Jan. 22, 2019, 4:40 p.m. |
| Kaskade-S/T — Part 1 | 100 | Jan. 13, 2019, 11:43 a.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 200 | Jan. 9, 2019, 8:37 p.m. |
| Cracking SHA1-Hashed Passwords | 1,089 | Jan. 6, 2019, 8:35 p.m. |
| Image Noise | 100 | Jan. 5, 2019, 10:14 a.m. |
| Playfair Encryption | 100 | Jan. 1, 2019, 11:40 a.m. |
| Enigma Combinatorics | 100 | Dec. 16, 2018, 9:47 a.m. |
| A hidden word | 100 | Dec. 13, 2018, 1:42 p.m. |
| Turing Bombe Enigma I | 100 | Dec. 9, 2018, 9:21 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Nov. 29, 2018, 6:04 p.m. |
| The Einstein Enigma | 1,168 | Nov. 28, 2018, 11:38 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | Nov. 26, 2018, 7:56 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | Nov. 26, 2018, 7:46 p.m. |
| Enigma Messages | 100 | Nov. 20, 2018, 8:37 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Nov. 17, 2018, 8:30 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Nov. 17, 2018, 7:52 p.m. |
| Number Sequence — Part 9 | 100 | Oct. 23, 2018, 8:45 p.m. |
| Number Sequence — Part 7 | 100 | Oct. 8, 2018, 8:37 p.m. |
| ADFGVX — Part 1 | 100 | Oct. 4, 2018, 10:31 a.m. |
| ADFGVX — Part 2 | 100 | Oct. 3, 2018, 2:02 p.m. |
| Autokey Cipher | 117 | Oct. 1, 2018, 10:03 a.m. |
| Cascading Encryption — Part 1/3 | 100 | Sept. 23, 2018, 6:21 p.m. |
| Molehunt (Part 3/3) | 1,088 | Sept. 16, 2018, 4:27 p.m. |
| Molehunt (Part 1/3) | 100 | Sept. 16, 2018, 10 a.m. |
| Molehunt (Part 2/3) | 100 | Sept. 15, 2018, 9:30 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Aug. 23, 2018, 11:29 a.m. |
| Reserve Hand Procedure — Part 1 | 100 | Aug. 21, 2018, 4:51 p.m. |
| Playfair with hints about the grid | 100 | Aug. 18, 2018, 4:24 p.m. |
| Snow White and the seven dwarfs | 100 | Aug. 17, 2018, 1:28 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Aug. 10, 2018, 9:50 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Aug. 9, 2018, 5:39 p.m. |
| Factorization Cipher — Part 1 | 100 | Aug. 7, 2018, 3:20 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Aug. 5, 2018, 10:50 a.m. |
| Trifid Cipher | 100 | July 31, 2018, 2:15 p.m. |
| Pigpen with a twist — Part 1 | 100 | July 27, 2018, 11:58 a.m. |
| News from Castle Mansfeld | 100 | July 25, 2018, 4:02 p.m. |
| A Secret Message from Castle Mansfeld | 100 | July 24, 2018, 2:24 p.m. |
| Advent-Challenge — Part 1 | 101 | June 5, 2018, 9:22 a.m. |
| The Last Note | 100 | July 21, 2017, 5:15 p.m. |
| Number Sequence — Part 3 | 100 | July 12, 2017, 4:46 p.m. |
| One-Time Pad with Flaws | 100 | June 27, 2017, 10:26 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | June 18, 2017, 10:04 p.m. |
| Classical Ciphers^3 | 100 | June 9, 2017, 4:14 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | June 7, 2017, 6:34 p.m. |
| Number Sequence — Part 8 | 100 | June 3, 2017, 9:26 p.m. |
| Strange Message from Thessaloniki | 100 | May 20, 2017, 8:18 p.m. |
| Letter to the Templars — Part 3 | 1,102 | May 12, 2017, 12:39 p.m. |
| Letter to the Templars — Part 2 | 100 | May 8, 2017, 1:41 p.m. |
| Letter to the Templars — Part 1 | 100 | May 7, 2017, 9:53 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | May 5, 2017, 9:20 p.m. |
| M-138 — Part 1 | 100 | April 23, 2017, 10:52 a.m. |
| Modified Caesar Cipher | 100 | April 2, 2017, 11:40 a.m. |
| Nils away on travel | 100 | April 1, 2017, 2:27 p.m. |
| From Russia with Love | 100 | March 24, 2017, 9:07 p.m. |
| Number Sequence — Part 4 | 100 | March 24, 2017, 10:41 a.m. |
| Grille Cipher | 100 | March 23, 2017, 8:32 p.m. |
| How do you become a big cryptographer? | 100 | March 23, 2017, 8:59 a.m. |
| Monoalphabetic Substitution | 100 | March 21, 2017, 6:25 p.m. |
| Beaver Code | 100 | March 17, 2017, 8:50 a.m. |
| Caesar Encryption | 100 | March 15, 2017, 10:01 a.m. |
| Number Sequence — Part 2 | 100 | March 14, 2017, 8:09 p.m. |
| Original Caesar Cipher | 100 | March 14, 2017, 7:51 p.m. |
| Number Sequence | 100 | March 14, 2017, 6:24 p.m. |
Gold1
Silver0
Bronze2
