| The Hutton Cipher – Part 2 | 2,000 | June 6, 2023, 6:14 a.m. |
| The Hutton Cipher – Part 1 | 2,000 | May 3, 2023, 6:41 a.m. |
| Spirale — Part 1 | 1,089 | March 31, 2023, 7:14 a.m. |
| Spirale — Part 2 | 1,089 | March 31, 2023, 6:57 a.m. |
| The Josse Challenge – Part 3 | 1,824 | March 29, 2023, 6:54 a.m. |
| The Josse Challenge – Part 2 | 2,000 | Feb. 25, 2023, 9:19 a.m. |
| The Josse Challenge – Part 1 | 1,824 | Feb. 11, 2023, 4:37 p.m. |
| The Syllabary Cipher – Part 5 | 1,324 | Dec. 1, 2022, 7:56 a.m. |
| The Syllabary Cipher – Part 4 | 1,327 | Nov. 30, 2022, 8:21 a.m. |
| The Syllabary Cipher – Part 3 | 1,327 | Nov. 30, 2022, 7:15 a.m. |
| The Syllabary Cipher – Part 2 | 1,469 | Nov. 7, 2022, 1:22 p.m. |
| The Syllabary Cipher – Part 1 | 117 | Nov. 3, 2022, 7:30 a.m. |
| Weakened ElsieFour — Part 1 | 1,105 | June 24, 2022, 2:45 p.m. |
| RSA Factoring Challenge: RSA-704 | 0 | June 22, 2022, 7:55 a.m. |
| RSA Factoring Challenge: RSA-230 | 0 | June 22, 2022, 7:53 a.m. |
| RSA Factoring Challenge: RSA-220 | 0 | June 22, 2022, 7:51 a.m. |
| RSA Factoring Challenge: RSA-210 | 0 | June 22, 2022, 7:48 a.m. |
| Flawed Usage of a OTP Cipher by the BND | 1,092 | June 21, 2022, 1:07 p.m. |
| Kaskade-S/T — Part 3 | 1,080 | June 15, 2022, 12:52 p.m. |
| Purple 1 | 1,080 | June 11, 2022, 8:42 a.m. |
| Pigpen with a twist — Part 3 | 1,081 | June 4, 2022, 7:29 a.m. |
| Pigpen with a twist — Part 2 | 1,081 | June 4, 2022, 7 a.m. |
| ASAC — A Strong(er) ADFGVX Cipher — Part 1 | 1,096 | June 2, 2022, 8:38 a.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,082 | June 1, 2022, 8:36 a.m. |
| Wheatstone Cryptograph — Part 2 | 1,156 | May 30, 2022, 2:53 p.m. |
| Spanish Strip Cipher — Part 2 | 1,087 | May 28, 2022, 11:53 a.m. |
| Spanish Strip Cipher — Part 1 | 1,087 | May 26, 2022, 5:25 p.m. |
| Cascading Encryption — Part 2/3 | 1,085 | May 26, 2022, 1 p.m. |
| M-138 — Part 4 | 1,090 | May 23, 2022, 7:38 a.m. |
| M-138 — Part 3 | 1,090 | May 21, 2022, 5:09 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,082 | May 20, 2022, 11:38 a.m. |
| Polyphonic Substitution Cipher — Part 2 | 1,123 | May 19, 2022, 12:34 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 1,121 | May 18, 2022, 5:20 p.m. |
| Modified Vigenère Cipher | 1,222 | May 17, 2022, 1:09 p.m. |
| AES ECB Wrong Encoding | 1,104 | May 15, 2022, 7:18 a.m. |
| Music Code — Part 1 | 100 | May 14, 2022, 7:33 a.m. |
| Music Code — Part 2 | 1,081 | May 13, 2022, 6:51 p.m. |
| Keyshanc — Part 2 | 1,083 | May 6, 2022, 7:14 a.m. |
| Keyshanc — Part 1 | 1,083 | May 5, 2022, 1:03 p.m. |
| Handycipher made in love — Part 2 | 1,116 | May 3, 2022, 2:59 p.m. |
| An 'unhearable' message | 100 | May 3, 2022, 1:58 p.m. |
| Handycipher made in love — Part 1 | 1,113 | May 2, 2022, 4:37 p.m. |
| Enigma Combinatorics | 100 | May 2, 2022, 1:42 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | May 2, 2022, 7:39 a.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | May 2, 2022, 7:34 a.m. |
| Enigma Part 2 | 1,080 | May 2, 2022, 7:24 a.m. |
| Zodiac Cipher | 100 | May 1, 2022, 8:12 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | May 1, 2022, 7:39 a.m. |
| The Book Code: A Challenge for Bookworms | 100 | April 30, 2022, 7:38 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,080 | April 29, 2022, 12:48 p.m. |
| An Invisible Message | 100 | April 28, 2022, 1:11 p.m. |
| Advent Challenge — Part 4 | 1,104 | April 28, 2022, 8:25 a.m. |
| Smartcard RSA | 1,080 | April 27, 2022, 4:01 p.m. |
| Advent Challenge — Part 3 | 1,104 | April 27, 2022, 1:25 p.m. |
| A really long number sequence | 1,081 | April 27, 2022, 7:50 a.m. |
| Unconcealed RSA messages | 1,082 | April 26, 2022, 12:49 p.m. |
| Kaskade-S/T — Part 2 | 1,080 | April 25, 2022, 7:18 a.m. |
| The SZ42 Challenge — Part 12 | 1,189 | April 19, 2022, 2:35 p.m. |
| The SZ42 Challenge — Part 13 | 1,189 | April 19, 2022, 8:02 a.m. |
| A Cloaked Substitution Cipher — Part 2 | 1,119 | April 18, 2022, 4:03 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | April 17, 2022, 3:20 p.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,083 | April 17, 2022, 7:49 a.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,082 | April 16, 2022, 12:22 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,082 | April 16, 2022, 12:05 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | April 16, 2022, 12:05 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | April 15, 2022, 6:37 p.m. |
| Advent-Challenge — Part 2 | 1,104 | April 15, 2022, 4:46 p.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,119 | April 15, 2022, 4:26 p.m. |
| A hidden word — Part 2 | 100 | April 15, 2022, 11:54 a.m. |
| ECDH-Key Exchange for Beginners | 100 | April 14, 2022, 4:48 p.m. |
| Recycled One-Time Pad | 100 | April 14, 2022, 2:55 p.m. |
| Kaskade-S/T — Part 1 | 100 | April 13, 2022, 12:02 p.m. |
| Hybrid Encryption I | 1,080 | April 13, 2022, 8:25 a.m. |
| BCR code (Book-Caesar-RSA) | 1,084 | April 12, 2022, 10:18 a.m. |
| ORYX Stream Cipher Part I | 1,080 | April 11, 2022, 2:01 p.m. |
| News from Castle Mansfeld | 100 | April 10, 2022, 12:01 p.m. |
| A Secret Message from Castle Mansfeld | 100 | April 9, 2022, 6:43 p.m. |
| The SZ42 Challenge — Part 6 | 1,140 | April 9, 2022, 1:41 p.m. |
| Polyhomophonic Substitution — Part 2 | 1,129 | April 8, 2022, 2:20 p.m. |
| The SZ42 Challenge — Part 9 | 1,146 | April 8, 2022, 7:04 a.m. |
| Ku Klux Klan | 1,000 | April 8, 2022, 12:21 a.m. |
| Double Column Transposition — Part 5 | 1,089 | April 4, 2022, 8:25 a.m. |
| Weakened Granit — Part 1 | 100 | April 3, 2022, 4:03 p.m. |
| Double Column Transposition — Part 1 | 1,088 | April 1, 2022, 12:40 p.m. |
| Double Column Transposition — Part 2 | 1,088 | March 31, 2022, 10:34 a.m. |
| Double Column Transposition — Part 4 | 1,088 | March 26, 2022, 7:53 a.m. |
| Double Column Transposition — Part 3 | 1,088 | March 25, 2022, 7:22 p.m. |
| RSA with Special d | 13,034 | March 24, 2022, 9:51 p.m. |
| CMEA 1 | 1,080 | March 23, 2022, 2:31 p.m. |
| Factorization Cipher — Part 3 | 1,082 | March 23, 2022, 11:19 a.m. |
| New Year's Greetings — Part 4 | 100 | March 22, 2022, 8:35 p.m. |
| New Year's Greetings — Part 3 | 100 | March 22, 2022, 8:22 p.m. |
| New Year's Greetings — Part 2 | 100 | March 22, 2022, 8:19 p.m. |
| New Year's Greetings — Part 1 | 100 | March 22, 2022, 8:16 p.m. |
| Turing Bombe Enigma I | 100 | March 22, 2022, 7:47 a.m. |
| Find the right route — Part 1 | 100 | March 21, 2022, 4:03 p.m. |
| The Einstein Enigma | 1,106 | March 17, 2022, 1:38 p.m. |
| The SZ42 Challenge — Part 7 | 1,143 | March 17, 2022, 8:33 a.m. |
| The SZ42 Challenge — Part 8 | 1,144 | March 16, 2022, 8:02 a.m. |
| The SZ42 Challenge — Part 4 | 1,139 | March 16, 2022, 7:08 a.m. |
| The SZ42 Challenge — Part 5 | 1,139 | March 16, 2022, 7:07 a.m. |
| The SZ42 Challenge — Part 3 | 1,138 | March 15, 2022, 7:06 a.m. |
| The SZ42 Challenge — Part 2 | 1,137 | March 14, 2022, 1:37 p.m. |
| The SZ42 Challenge — Part 1 | 1,136 | March 14, 2022, 8 a.m. |
| The T52 Sturgeon Challenge — Part 3 | 1,119 | March 11, 2022, 10:09 a.m. |
| The T52 Sturgeon Challenge — Part 2 | 1,119 | March 10, 2022, 11:18 a.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,119 | March 9, 2022, 4:07 p.m. |
| Cipher ID — Part 1 | 1,124 | March 6, 2022, 2:53 p.m. |
| Lattice Part 1 | 1,081 | Feb. 15, 2022, 7:43 a.m. |
| Lightweight Introduction to Lattices — Part 3 | 1,138 | Feb. 14, 2022, 7:17 a.m. |
| Cascading Encryption — Part 1/3 | 100 | Feb. 13, 2022, 1:49 p.m. |
| Lightweight Introduction to Lattices — Part 1 | 100 | Feb. 11, 2022, 8:12 a.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Feb. 7, 2022, 8:25 a.m. |
| Homophonic Encryption — Part 4 | 1,118 | Feb. 5, 2022, 8:08 a.m. |
| Homophonic Encryption — Part 3 | 1,118 | Feb. 5, 2022, 7:52 a.m. |
| Homophonic Encryption — Part 2 | 1,118 | Feb. 4, 2022, 8:12 a.m. |
| Homophonic Encryption — Part 1 | 1,118 | Feb. 4, 2022, 7:43 a.m. |
| Polyhomophonic Substitution — Part 1 | 100 | Feb. 3, 2022, 2:14 p.m. |
| ADFGVX — Part 2 | 100 | Jan. 31, 2022, 1:20 p.m. |
| ADFGVX — Part 1 | 100 | Jan. 31, 2022, 8:25 a.m. |
| Classical Ciphers^3 | 100 | Jan. 28, 2022, 5:05 p.m. |
| Number Sequence — Part 9 | 100 | Jan. 28, 2022, 2:31 p.m. |
| Typex — Part 2 | 1,086 | Jan. 27, 2022, 11:04 a.m. |
| Typex — Part 1 | 1,085 | Jan. 25, 2022, 12:10 p.m. |
| Trendy Messenger | 1,109 | Jan. 19, 2022, 7:18 a.m. |
| ¿No Hablas Español? No problemo! | 100 | Jan. 7, 2022, 3:48 p.m. |
| Pigpen with a twist — Part 1 | 100 | Jan. 7, 2022, 7:32 a.m. |
| Double Columnar Transposition | 100 | Jan. 6, 2022, 3:23 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | Jan. 6, 2022, 7:44 a.m. |
| Molehunt (Part 3/3) | 1,080 | Dec. 20, 2021, 8:13 a.m. |
| Molehunt (Part 2/3) | 100 | Dec. 9, 2021, 8:36 a.m. |
| Molehunt (Part 1/3) | 100 | Dec. 9, 2021, 8:08 a.m. |
| Playfair Encryption | 100 | Dec. 3, 2021, 7:50 a.m. |
| Playfair with hints about the grid | 100 | Dec. 2, 2021, 2:41 p.m. |
| Enigma Messages | 100 | Dec. 2, 2021, 2:24 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Dec. 2, 2021, 8:25 a.m. |
| Hill Cipher with Sudoku Key | 100 | Dec. 2, 2021, 7:34 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Dec. 1, 2021, 10:49 a.m. |
| Summer Job | 1,111 | Nov. 30, 2021, 7:45 a.m. |
| Unusual encryption using a diophantine equation | 1,082 | Nov. 29, 2021, 11:54 a.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,081 | Nov. 29, 2021, 8:26 a.m. |
| Enigma Part 1 | 1,080 | Nov. 26, 2021, 10:50 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,082 | Nov. 26, 2021, 7:59 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Nov. 19, 2021, 8:27 a.m. |
| Nils away on travel | 100 | Nov. 18, 2021, 1:27 p.m. |
| From Russia with Love | 100 | Nov. 18, 2021, 1:20 p.m. |
| Number Sequence — Part 6 | 100 | Nov. 18, 2021, 12:59 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | Nov. 18, 2021, 12:40 p.m. |
| Advent-Challenge — Part 1 | 100 | Nov. 18, 2021, 12:34 p.m. |
| Autokey Cipher | 100 | Nov. 18, 2021, 12:28 p.m. |
| Wheatstone Cryptograph — Part 1 | 100 | Nov. 18, 2021, 8:07 a.m. |
| Cracking SHA1-Hashed Passwords | 1,081 | Nov. 17, 2021, 2:34 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,118 | Nov. 17, 2021, 8:16 a.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 1,134 | Nov. 17, 2021, 7:45 a.m. |
| Factorization Cipher — Part 2 | 1,083 | Nov. 16, 2021, 7:38 a.m. |
| The Last Note | 100 | Nov. 12, 2021, 12:57 p.m. |
| How do you become a big cryptographer? | 100 | Nov. 11, 2021, 1:01 p.m. |
| Modular Sequences | 100 | Nov. 11, 2021, 12:56 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Nov. 10, 2021, 12:57 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Nov. 10, 2021, 12:45 p.m. |
| One-Time Pad with Flaws | 100 | Nov. 10, 2021, 6:09 a.m. |
| RSA: Two different keys — same ciphertext | 1,088 | Aug. 19, 2019, 7:26 a.m. |
| Fastest in the West | 1,150 | Aug. 18, 2019, 12:10 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,086 | Aug. 3, 2019, 7:30 a.m. |
| Alice's Birthday Party (Part 2) | 1,086 | Aug. 3, 2019, 7:02 a.m. |
| Alice's Birthday Party (Part 1) | 1,086 | Aug. 2, 2019, 6:01 p.m. |
| Trifid Cipher | 100 | Aug. 2, 2019, 8:05 a.m. |
| Monoalphabetic Substitution | 100 | July 31, 2019, 5:12 p.m. |
| Image Noise | 100 | July 31, 2019, 7:55 a.m. |
| M-138 — Part 2 | 1,102 | July 30, 2019, 10:42 a.m. |
| M-138 — Part 1 | 100 | July 30, 2019, 7:43 a.m. |
| Snow White and the seven dwarfs | 100 | July 30, 2019, 7:20 a.m. |
| A hidden word | 100 | July 30, 2019, 6:49 a.m. |
| Letter to the Templars — Part 3 | 1,092 | July 29, 2019, 3:17 p.m. |
| Letter to the Templars — Part 2 | 100 | July 29, 2019, 3:09 p.m. |
| Letter to the Templars — Part 1 | 100 | July 29, 2019, 2:58 p.m. |
| Beaver Code | 100 | July 29, 2019, 2:04 p.m. |
| Factorization Cipher — Part 1 | 100 | July 29, 2019, 7:43 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | July 29, 2019, 6:56 a.m. |
| Grille Cipher | 100 | July 28, 2019, 4:11 p.m. |
| Modified Caesar Cipher | 100 | July 28, 2019, 11:18 a.m. |
| Number Sequence — Part 10 | 100 | July 27, 2019, 6:02 p.m. |
| Number Sequence — Part 8 | 100 | July 27, 2019, 5:53 p.m. |
| Number Sequence — Part 7 | 100 | July 27, 2019, 5:42 p.m. |
| Number Sequence — Part 5 | 100 | July 27, 2019, 5:25 p.m. |
| Number Sequence — Part 4 | 100 | July 27, 2019, 5:15 p.m. |
| Number Sequence — Part 3 | 100 | July 27, 2019, 5:01 p.m. |
| Number Sequence — Part 2 | 100 | July 27, 2019, 4:54 p.m. |
| Original Caesar Cipher | 100 | July 27, 2019, 7:36 a.m. |
| Number Sequence | 100 | July 27, 2019, 7:32 a.m. |
| Caesar Encryption | 100 | July 27, 2019, 7:22 a.m. |
Gold0
Silver1
Bronze2
