| The Syllabary Cipher – Part 1 | 108 | Nov. 8, 2022, 4:13 p.m. |
| Typex — Part 2 | 1,084 | Aug. 12, 2022, 7:41 p.m. |
| Typex — Part 1 | 1,084 | Aug. 12, 2022, 3:13 p.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 1,122 | Aug. 8, 2022, 7:21 p.m. |
| Alberti Challenge — Part 1 | 101 | July 10, 2022, 6:09 p.m. |
| Find the right route — Part 2 | 101 | May 5, 2021, 8:42 p.m. |
| Wheatstone Cryptograph — Part 1 | 108 | May 4, 2021, 5:11 p.m. |
| Pigpen with a twist — Part 3 | 1,084 | May 3, 2021, 5:25 p.m. |
| Cipher ID — Part 1 | 1,143 | April 10, 2021, 10:59 p.m. |
| The SZ42 Challenge — Part 2 | 1,178 | April 3, 2021, 3:40 p.m. |
| The SZ42 Challenge — Part 1 | 1,175 | April 3, 2021, 3:07 a.m. |
| Find the right route — Part 1 | 102 | Dec. 16, 2020, 7:30 p.m. |
| Lightweight Introduction to Lattices — Part 1 | 101 | July 30, 2020, 10:27 p.m. |
| Polyhomophonic Substitution — Part 1 | 103 | April 23, 2020, 7:15 p.m. |
| Polyphonic Substitution Cipher — Part 1 | 1,337 | Dec. 20, 2019, 6:42 p.m. |
| The T52 Sturgeon Challenge — Part 3 | 1,238 | Oct. 21, 2019, 9:48 p.m. |
| The T52 Sturgeon Challenge — Part 2 | 1,238 | Oct. 20, 2019, 8:34 p.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,232 | Oct. 19, 2019, 5:45 p.m. |
| A Cloaked Substitution Cipher — Part 2 | 1,290 | Oct. 12, 2019, 6:28 a.m. |
| A Cloaked Substitution Cipher — Part 1 | 1,286 | Oct. 10, 2019, 2:25 a.m. |
| Handycipher — Part 2 | 1,104 | July 21, 2019, 5:29 p.m. |
| Weakened Handycipher — Part 1 | 1,106 | June 25, 2019, 12:12 a.m. |
| Weakened Handycipher — Part 3 | 1,106 | June 15, 2019, 3:11 a.m. |
| Weakened Handycipher — Part 2 | 1,106 | June 14, 2019, 12:42 a.m. |
| Handycipher made in love — Part 2 | 1,469 | May 31, 2019, 11:52 p.m. |
| Handycipher made in love — Part 1 | 1,227 | May 31, 2019, 1:45 p.m. |
| Homophonic Encryption — Part 4 | 1,456 | May 20, 2019, 1:42 p.m. |
| Homophonic Encryption — Part 3 | 1,469 | May 19, 2019, 6:21 a.m. |
| Homophonic Encryption — Part 2 | 1,469 | May 19, 2019, 5:44 a.m. |
| Homophonic Encryption — Part 1 | 1,444 | May 17, 2019, 3:56 a.m. |
| Pigpen with a twist — Part 2 | 1,089 | April 24, 2019, 12:10 a.m. |
| Smartcard RSA | 1,087 | April 17, 2019, 1:17 a.m. |
| Kaskade-S/T — Part 3 | 1,088 | Feb. 22, 2019, 3:35 a.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,660 | Feb. 19, 2019, 5:26 p.m. |
| Unconcealed RSA messages | 1,090 | Feb. 15, 2019, 11:12 p.m. |
| Monoalphabetic Substitution with Camouflage — Part 5 | 1,092 | Feb. 3, 2019, 4:40 a.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,091 | Feb. 3, 2019, 4:17 a.m. |
| Spanish Strip Cipher — Part 2 | 1,101 | Feb. 3, 2019, 1:45 a.m. |
| Spanish Strip Cipher — Part 1 | 1,101 | Jan. 30, 2019, 5:36 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 200 | Jan. 10, 2019, 1:53 p.m. |
| Ku Klux Klan | 1,000 | Dec. 11, 2018, 3:48 p.m. |
| Double Column Transposition — Part 4 | 1,103 | Nov. 23, 2018, 5:32 p.m. |
| Double Column Transposition — Part 1 | 1,102 | Nov. 22, 2018, 10:50 p.m. |
| Double Column Transposition — Part 3 | 1,103 | Nov. 21, 2018, 11:44 p.m. |
| Double Column Transposition — Part 2 | 1,103 | Nov. 19, 2018, 10:41 p.m. |
| RSA Factoring Challenge: RSA-210 | 0 | Nov. 6, 2018, 5:32 p.m. |
| RSA Factoring Challenge: RSA-220 | 0 | Nov. 6, 2018, 5:30 p.m. |
| RSA Factoring Challenge: RSA-704 | 0 | Nov. 6, 2018, 5:28 p.m. |
| RSA Factoring Challenge: RSA-230 | 0 | Nov. 6, 2018, 5:26 p.m. |
| CMEA 2 | 13,184 | Nov. 6, 2018, 11:37 a.m. |
| Breaking a Filter Generator | 1,318 | Oct. 30, 2018, 6:04 p.m. |
| Weakened Granit — Part 1 | 100 | Oct. 29, 2018, 11:34 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,089 | Oct. 28, 2018, 3:16 a.m. |
| Cryptanalysis Hacking Puzzles — Part 1 | 150 | Oct. 28, 2018, 1:43 a.m. |
| Number Sequence — Part 7 | 100 | Oct. 23, 2018, 2:40 a.m. |
| An Invisible Message | 100 | Oct. 22, 2018, 11:18 p.m. |
| Trendy Messenger | 1,212 | Oct. 22, 2018, 10:43 p.m. |
| Fastest in the West | 1,212 | Oct. 21, 2018, 8:56 p.m. |
| Summer Job | 1,217 | Oct. 13, 2018, 3:24 a.m. |
| Unusual encryption using a diophantine equation | 1,091 | Oct. 13, 2018, 2:35 a.m. |
| A really long number sequence | 1,091 | Oct. 12, 2018, 2:55 a.m. |
| Molehunt (Part 3/3) | 1,088 | Oct. 10, 2018, 2:22 a.m. |
| M-138 — Part 4 | 1,108 | Oct. 8, 2018, 7:11 p.m. |
| Advent Challenge — Part 3 | 1,169 | Oct. 6, 2018, 2:31 p.m. |
| Advent Challenge — Part 4 | 1,168 | Oct. 6, 2018, 4:22 a.m. |
| Advent-Challenge — Part 2 | 1,168 | Oct. 4, 2018, 3:41 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,093 | Oct. 1, 2018, 4:42 p.m. |
| CMEA 1 | 1,089 | Sept. 30, 2018, 8:59 p.m. |
| Modular Sequences | 150 | Sept. 26, 2018, 8:55 p.m. |
| Autokey Cipher | 150 | Sept. 26, 2018, 8:28 p.m. |
| M-138 — Part 3 | 1,108 | Sept. 24, 2018, 11:45 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Sept. 24, 2018, 8:39 p.m. |
| Zodiac Cipher | 100 | Sept. 23, 2018, 7:49 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Sept. 23, 2018, 7:15 p.m. |
| Playfair with hints about the grid | 100 | Sept. 23, 2018, 5:37 p.m. |
| Playfair Encryption | 100 | Sept. 23, 2018, 5:07 p.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,092 | Sept. 15, 2018, 4:30 a.m. |
| ORYX Stream Cipher Part II | 1,088 | Sept. 14, 2018, 1:06 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Sept. 13, 2018, 3:02 a.m. |
| Turing Bombe Enigma I | 100 | Sept. 9, 2018, 4:52 p.m. |
| Kaskade-S/T — Part 2 | 1,089 | Sept. 8, 2018, 3:14 p.m. |
| Kaskade-S/T — Part 1 | 100 | Sept. 7, 2018, 6:43 p.m. |
| ADFGVX — Part 1 | 100 | Sept. 7, 2018, 3:22 a.m. |
| ADFGVX — Part 2 | 100 | Sept. 4, 2018, 6:45 p.m. |
| The Einstein Enigma | 1,185 | Sept. 3, 2018, 6:05 a.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,093 | Sept. 3, 2018, 3:34 a.m. |
| Factorization Cipher — Part 3 | 1,093 | Sept. 2, 2018, 12:22 a.m. |
| Keyshanc — Part 1 | 1,094 | Sept. 1, 2018, 7:26 p.m. |
| BCR code (Book-Caesar-RSA) | 1,095 | Aug. 31, 2018, 11:31 p.m. |
| Enigma Part 2 | 1,088 | Aug. 29, 2018, 12:54 a.m. |
| Enigma Messages | 100 | Aug. 27, 2018, 2:50 a.m. |
| Factorization Cipher — Part 2 | 1,092 | Aug. 26, 2018, 3:08 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Aug. 23, 2018, 2:11 a.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | Aug. 23, 2018, 12:56 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | Aug. 23, 2018, 12:43 a.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Aug. 22, 2018, 12:09 a.m. |
| Enigma Part 1 | 1,088 | Aug. 21, 2018, 11:12 p.m. |
| RSA: Two different keys — same ciphertext | 1,091 | Aug. 20, 2018, 2:31 a.m. |
| M-138 — Part 2 | 1,109 | Aug. 19, 2018, 10:52 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,088 | Aug. 19, 2018, 10:41 p.m. |
| Hybrid Encryption I | 1,089 | Aug. 19, 2018, 2:21 p.m. |
| ORYX Stream Cipher Part I | 1,088 | Aug. 18, 2018, 5:56 a.m. |
| Cascading Encryption — Part 1/3 | 100 | Aug. 15, 2018, 7:03 p.m. |
| Recycled One-Time Pad | 100 | Aug. 14, 2018, 2:05 a.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,089 | Aug. 7, 2018, 3:17 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,091 | Aug. 7, 2018, 2:15 a.m. |
| Alice's Birthday Party (Part 2) | 1,089 | Aug. 7, 2018, 2:01 a.m. |
| Alice's Birthday Party (Part 1) | 1,089 | Aug. 3, 2018, 4:49 p.m. |
| Cracking SHA1-Hashed Passwords | 1,090 | Aug. 3, 2018, 2:02 p.m. |
| Letter to the Templars — Part 3 | 1,096 | Aug. 3, 2018, 3:39 a.m. |
| The Book Code: A Challenge for Bookworms | 100 | Aug. 1, 2018, 2:22 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | July 31, 2018, 6:28 p.m. |
| Classical Ciphers^3 | 100 | July 30, 2018, 1:51 a.m. |
| Enigma Combinatorics | 100 | July 23, 2018, 5:11 p.m. |
| Image Noise | 100 | July 23, 2018, 4:01 a.m. |
| Number Sequence — Part 9 | 100 | July 20, 2018, 5:37 p.m. |
| Number Sequence — Part 6 | 100 | July 20, 2018, 5:20 p.m. |
| Double Columnar Transposition | 100 | July 17, 2018, 12:23 p.m. |
| ECDH-Key Exchange for Beginners | 100 | July 17, 2018, 3:06 a.m. |
| The Last Note | 100 | July 17, 2018, 2:21 a.m. |
| Heartbleed — Part 2 | 100 | July 16, 2018, 1:37 a.m. |
| Heartbleed — Part 1 | 100 | July 16, 2018, 1:34 a.m. |
| A hidden word — Part 2 | 100 | July 15, 2018, 10:38 p.m. |
| Molehunt (Part 2/3) | 100 | July 15, 2018, 9:47 p.m. |
| Molehunt (Part 1/3) | 100 | July 15, 2018, 9:29 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | July 11, 2018, 1:34 a.m. |
| Snow White and the seven dwarfs | 100 | July 8, 2018, 8:28 p.m. |
| Number Sequence — Part 10 | 101 | July 7, 2018, 5:49 a.m. |
| Multilingual Monoalphabetic Substitution | 100 | July 7, 2018, 5:21 a.m. |
| Nils away on travel | 100 | July 6, 2018, 7:47 p.m. |
| Trifid Cipher | 100 | July 6, 2018, 2:09 a.m. |
| Hill Cipher with Sudoku Key | 100 | July 5, 2018, 12:59 a.m. |
| M-138 — Part 1 | 100 | July 3, 2018, 9:44 p.m. |
| Pigpen with a twist — Part 1 | 100 | July 2, 2018, 5:06 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | July 2, 2018, 3:37 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | July 2, 2018, 4:23 a.m. |
| ¿No Hablas Español? No problemo! | 100 | July 2, 2018, 4:12 a.m. |
| Number Sequence — Part 5 | 100 | July 1, 2018, 8:21 p.m. |
| From Russia with Love | 100 | June 25, 2018, 3:11 a.m. |
| Advent-Challenge — Part 1 | 101 | June 24, 2018, 8:21 p.m. |
| Modified Caesar Cipher | 100 | June 24, 2018, 8:20 p.m. |
| How do you become a big cryptographer? | 100 | June 24, 2018, 8:12 p.m. |
| Number Sequence — Part 8 | 100 | June 22, 2018, 3:52 a.m. |
| One-Time Pad with Flaws | 100 | June 21, 2018, 4:59 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | June 21, 2018, 4:15 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | June 21, 2018, 2:55 p.m. |
| Grille Cipher | 100 | June 21, 2018, 1:44 p.m. |
| Factorization Cipher — Part 1 | 100 | June 21, 2018, 2:43 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | June 21, 2018, 1:11 a.m. |
| Monoalphabetic Substitution | 100 | June 20, 2018, 3:27 a.m. |
| A hidden word | 100 | June 11, 2018, 10:37 p.m. |
| Number Sequence — Part 4 | 100 | June 11, 2018, 10:28 p.m. |
| Letter to the Templars — Part 2 | 100 | June 11, 2018, 2:58 a.m. |
| Number Sequence — Part 3 | 100 | June 11, 2018, 2:40 a.m. |
| Letter to the Templars — Part 1 | 100 | June 11, 2018, 1:40 a.m. |
| Beaver Code | 100 | June 11, 2018, 1:27 a.m. |
| Caesar Encryption | 100 | June 10, 2018, 9:54 p.m. |
| Number Sequence — Part 2 | 100 | June 10, 2018, 9:42 p.m. |
| Original Caesar Cipher | 100 | June 10, 2018, 9:39 p.m. |
| Number Sequence | 100 | June 10, 2018, 4:10 p.m. |
Gold1
Silver0
Bronze0
