| The Syllabary Cipher – Part 1 | 100 | Oct. 18, 2023, 10:41 a.m. |
| RSA Factoring Challenge: RSA-230 | 0 | March 14, 2019, 10:07 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 102 | March 7, 2019, 9:54 a.m. |
| Handycipher made in love — Part 1 | 1,406 | March 4, 2019, 2:32 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,444 | Feb. 28, 2019, 4:30 p.m. |
| Trendy Messenger | 1,199 | Nov. 23, 2018, 9:37 p.m. |
| Fastest in the West | 1,206 | Nov. 3, 2018, 9:05 p.m. |
| Cryptanalysis Hacking Puzzles — Part 1 | 113 | Nov. 3, 2018, 12:57 p.m. |
| Summer Job | 1,206 | Nov. 3, 2018, 12:37 p.m. |
| Unconcealed RSA messages | 1,091 | Nov. 3, 2018, 10:41 a.m. |
| Modular Sequences | 103 | Nov. 1, 2018, 7:44 p.m. |
| Autokey Cipher | 103 | Oct. 29, 2018, 10:51 p.m. |
| Number Sequence — Part 10 | 113 | April 25, 2018, 11:01 p.m. |
| The Einstein Enigma | 1,414 | Feb. 23, 2018, 9:36 p.m. |
| Advent Challenge — Part 3 | 1,576 | Dec. 28, 2017, 4:21 p.m. |
| Advent Challenge — Part 4 | 1,547 | Dec. 28, 2017, 2:16 p.m. |
| RSA Factoring Challenge: RSA-220 | 0 | Dec. 19, 2017, 10:48 p.m. |
| Advent-Challenge — Part 2 | 1,725 | Dec. 19, 2017, 6:36 p.m. |
| Advent-Challenge — Part 1 | 133 | Dec. 11, 2017, 2:50 p.m. |
| Number Sequence — Part 9 | 107 | Nov. 29, 2017, 10:29 p.m. |
| Ku Klux Klan | 1,000 | Sept. 9, 2016, 1:40 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,102 | Aug. 4, 2016, 10:22 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,102 | Aug. 3, 2016, 12:36 p.m. |
| Double Column Transposition — Part 4 | 1,126 | July 20, 2016, 9:51 p.m. |
| Double Column Transposition — Part 3 | 1,125 | July 18, 2016, 10:45 p.m. |
| Double Column Transposition — Part 2 | 1,125 | July 18, 2016, 6:03 p.m. |
| M-138 — Part 3 | 1,138 | July 18, 2016, 11:04 a.m. |
| Unusual encryption using a diophantine equation | 1,103 | March 29, 2016, 12:12 p.m. |
| New Year's Greetings — Part 5 | 1,725 | March 23, 2016, 3:46 p.m. |
| New Year's Greetings — Part 4 | 200 | March 21, 2016, 11:47 p.m. |
| New Year's Greetings — Part 3 | 200 | March 21, 2016, 11:19 p.m. |
| New Year's Greetings — Part 2 | 200 | March 21, 2016, 9:24 p.m. |
| New Year's Greetings — Part 1 | 200 | March 21, 2016, 8:58 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,106 | Feb. 26, 2016, 11:24 p.m. |
| Molehunt (Part 3/3) | 1,098 | Feb. 7, 2016, 11:39 a.m. |
| Heartbleed — Part 3 | 1,142 | Feb. 2, 2016, 4:31 p.m. |
| Music Code — Part 1 | 100 | Jan. 22, 2016, 9:41 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Jan. 19, 2016, 11:49 a.m. |
| Music Code — Part 2 | 1,102 | Jan. 15, 2016, 10:10 p.m. |
| An 'unhearable' message | 100 | Jan. 14, 2016, 3:44 p.m. |
| Strange Message from Thessaloniki | 100 | Jan. 13, 2016, 4:33 p.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Jan. 11, 2016, 6:20 p.m. |
| An Invisible Message | 100 | Dec. 8, 2015, 9:23 a.m. |
| News from Castle Mansfeld | 111 | Nov. 21, 2015, 8:43 p.m. |
| Image Noise | 200 | Nov. 21, 2015, 10:31 a.m. |
| Recycled One-Time Pad | 100 | Nov. 19, 2015, 3:45 p.m. |
| Playfair with hints about the grid | 100 | Oct. 4, 2015, 6:02 p.m. |
| Playfair Encryption | 100 | Oct. 4, 2015, 5:41 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | Sept. 30, 2015, 10 p.m. |
| Weakened Granit — Part 1 | 120 | Sept. 28, 2015, 6:19 p.m. |
| Number Sequence — Part 8 | 133 | Sept. 16, 2015, 7:02 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,112 | May 19, 2015, 6:31 p.m. |
| ECDH-Key Exchange for Beginners | 100 | May 7, 2015, 12:06 p.m. |
| ADFGVX — Part 1 | 100 | April 28, 2015, 6:37 p.m. |
| ADFGVX — Part 2 | 100 | April 28, 2015, 3:58 p.m. |
| Kaskade-S/T — Part 1 | 100 | April 27, 2015, 9:35 p.m. |
| Heartbleed — Part 2 | 100 | April 24, 2015, 11:36 p.m. |
| A really long number sequence | 1,109 | April 24, 2015, 10:01 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | April 23, 2015, 3:31 p.m. |
| RSA Factoring Challenge: RSA-704 | 0 | April 23, 2015, 3:29 p.m. |
| Zodiac Cipher | 100 | April 20, 2015, 5:33 p.m. |
| A hidden word — Part 2 | 200 | April 16, 2015, 10:46 p.m. |
| Heartbleed — Part 1 | 100 | April 15, 2015, 1:19 p.m. |
| Hill Cipher with Sudoku Key | 100 | April 13, 2015, 10:55 p.m. |
| BCR code (Book-Caesar-RSA) | 1,120 | April 12, 2015, 7:44 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,103 | April 7, 2015, 10:18 p.m. |
| Cascading Encryption — Part 1/3 | 100 | April 7, 2015, 9:31 p.m. |
| Hybrid Encryption I | 1,103 | April 7, 2015, 4:01 p.m. |
| Trifid Cipher | 100 | April 7, 2015, 3:06 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,103 | April 6, 2015, 12:12 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | April 4, 2015, 10:39 a.m. |
| M-138 — Part 2 | 1,230 | April 3, 2015, 7:20 p.m. |
| Pigpen with a twist — Part 1 | 100 | April 1, 2015, 2:50 p.m. |
| RSA: Two different keys — same ciphertext | 1,109 | April 1, 2015, 11:48 a.m. |
| Alice's Birthday Party (Part 2) | 1,103 | April 1, 2015, 10:15 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,109 | April 1, 2015, 9:53 a.m. |
| Alice's Birthday Party (Part 1) | 1,103 | April 1, 2015, 9:45 a.m. |
| Double Columnar Transposition | 100 | March 30, 2015, 9:38 p.m. |
| M-138 — Part 1 | 101 | March 28, 2015, 8:25 p.m. |
| Factorization Cipher — Part 3 | 1,113 | March 28, 2015, 7:37 p.m. |
| Number Sequence — Part 7 | 120 | March 27, 2015, 12:41 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | March 26, 2015, 7:33 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | March 25, 2015, 10:13 p.m. |
| Molehunt (Part 2/3) | 100 | March 25, 2015, 9:08 p.m. |
| Molehunt (Part 1/3) | 100 | March 25, 2015, 9:02 p.m. |
| Number Sequence — Part 6 | 150 | March 24, 2015, 12:35 p.m. |
| Classical Ciphers^3 | 100 | March 18, 2015, 11 p.m. |
| Factorization Cipher — Part 2 | 1,113 | March 9, 2015, 7:16 p.m. |
| The Last Note | 101 | March 4, 2015, 5:35 p.m. |
| Modified Caesar Cipher | 100 | March 3, 2015, 8:11 p.m. |
| Cracking SHA1-Hashed Passwords | 1,107 | March 2, 2015, 10:15 p.m. |
| One-Time Pad with Flaws | 100 | March 2, 2015, 5:50 p.m. |
| How do you become a big cryptographer? | 100 | March 1, 2015, 11:08 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Feb. 28, 2015, 8:02 p.m. |
| Nils away on travel | 100 | Feb. 28, 2015, 12:13 a.m. |
| Turing Bombe Enigma I | 100 | Feb. 26, 2015, 8:33 p.m. |
| Enigma Part 2 | 1,104 | Feb. 26, 2015, 7:33 p.m. |
| Enigma Part 1 | 1,104 | Feb. 26, 2015, 7:01 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Feb. 26, 2015, 6:23 p.m. |
| Number Sequence — Part 5 | 100 | Feb. 26, 2015, 3:10 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | Feb. 26, 2015, 9:16 a.m. |
| From Russia with Love | 100 | Feb. 25, 2015, 10:38 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Feb. 24, 2015, 8:08 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Feb. 24, 2015, 7:38 p.m. |
| Grille Cipher | 100 | Feb. 24, 2015, 5:52 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Feb. 24, 2015, 5:30 p.m. |
| A hidden word | 100 | Feb. 23, 2015, 9:37 p.m. |
| Enigma Combinatorics | 100 | Feb. 23, 2015, 7:42 p.m. |
| Letter to the Templars — Part 3 | 1,123 | Feb. 23, 2015, 12:04 p.m. |
| Letter to the Templars — Part 2 | 100 | Feb. 23, 2015, 11:53 a.m. |
| Letter to the Templars — Part 1 | 100 | Feb. 23, 2015, 11:46 a.m. |
| Number Sequence — Part 3 | 100 | Feb. 23, 2015, 9:16 a.m. |
| Snow White and the seven dwarfs | 100 | Feb. 22, 2015, 8:55 p.m. |
| Monoalphabetic Substitution | 100 | Feb. 22, 2015, 8:28 p.m. |
| Factorization Cipher — Part 1 | 100 | Feb. 22, 2015, 7:52 p.m. |
| Beaver Code | 100 | Feb. 21, 2015, 10:59 p.m. |
| Number Sequence — Part 2 | 100 | Feb. 21, 2015, 9:28 p.m. |
| Number Sequence — Part 4 | 100 | Feb. 21, 2015, 9:05 p.m. |
| Original Caesar Cipher | 100 | Feb. 21, 2015, 7:04 p.m. |
| Caesar Encryption | 100 | Feb. 21, 2015, 7:02 p.m. |
| Number Sequence | 100 | Feb. 21, 2015, 5:54 p.m. |
| Enigma Messages | 100 | Feb. 20, 2015, 6:02 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Feb. 19, 2015, 11:27 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | Feb. 19, 2015, 11:23 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | Feb. 19, 2015, 11:20 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Feb. 19, 2015, 11:16 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Feb. 19, 2015, 6:21 p.m. |
Gold0
Silver1
Bronze4
