| Alberti Challenge — Part 2 | 1,154 | June 11, 2023, 6:02 a.m. |
| Weakened Granit — Part 1 | 100 | Dec. 3, 2022, 6:16 a.m. |
| Playfair with hints about the grid | 100 | Dec. 1, 2022, 8:11 p.m. |
| Playfair Encryption | 100 | Dec. 1, 2022, 7:53 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 102 | Nov. 24, 2022, 2:36 p.m. |
| Trifid Cipher | 100 | Nov. 22, 2022, 7:01 p.m. |
| Pigpen with a twist — Part 1 | 100 | Nov. 20, 2022, 5:54 a.m. |
| ¿No Hablas Español? No problemo! | 100 | Nov. 18, 2022, 6:59 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Nov. 18, 2022, 3:21 p.m. |
| The T52 Sturgeon Challenge — Part 2 | 1,114 | Sept. 5, 2022, 8:48 a.m. |
| Molehunt (Part 3/3) | 1,079 | Aug. 30, 2022, 12:15 p.m. |
| Molehunt (Part 2/3) | 100 | July 8, 2022, 11:47 a.m. |
| Molehunt (Part 1/3) | 100 | July 8, 2022, 9:14 a.m. |
| Modular Sequences | 100 | June 29, 2022, 8:46 p.m. |
| Alberti Challenge — Part 1 | 107 | April 10, 2022, 4 p.m. |
| The T52 Sturgeon Challenge — Part 1 | 1,121 | Jan. 7, 2022, 11:40 p.m. |
| Nils away on travel | 100 | Nov. 21, 2021, 4:37 a.m. |
| Enigma Part 2 | 1,081 | Nov. 9, 2021, 2:39 p.m. |
| Enigma Part 1 | 1,081 | Nov. 5, 2021, 2:54 p.m. |
| Enigma Messages | 100 | Sept. 19, 2021, 1:12 p.m. |
| Turing Bombe Enigma I | 100 | Sept. 1, 2021, 8:11 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Aug. 25, 2021, 7:40 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | Aug. 25, 2021, 7:36 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Aug. 16, 2021, 8:32 a.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | Aug. 16, 2021, 8:07 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Aug. 15, 2021, 6:42 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,084 | July 20, 2021, 2:17 p.m. |
| Hill Cipher with Sudoku Key | 100 | July 18, 2021, 6:52 p.m. |
| Multilingual Monoalphabetic Substitution | 100 | July 16, 2021, 6:41 p.m. |
| Wheatstone Cryptograph — Part 1 | 102 | June 9, 2021, 4:01 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | May 31, 2021, 1:03 p.m. |
| How do you become a big cryptographer? | 100 | May 30, 2021, 3:39 p.m. |
| ADFGVX — Part 2 | 100 | April 26, 2021, 12:10 p.m. |
| ADFGVX — Part 1 | 100 | April 26, 2021, 11:02 a.m. |
| Summer Job | 1,117 | April 25, 2021, 9:14 p.m. |
| M-138 — Part 4 | 1,094 | March 19, 2021, 10:22 p.m. |
| M-138 — Part 3 | 1,094 | March 19, 2021, 8:06 p.m. |
| Number Sequence — Part 5 | 100 | March 14, 2021, 2:23 p.m. |
| M-138 — Part 2 | 1,094 | March 3, 2021, 6:01 p.m. |
| M-138 — Part 1 | 100 | March 2, 2021, 8:01 a.m. |
| Snow White and the seven dwarfs | 100 | March 2, 2021, 6:47 a.m. |
| Image Noise | 100 | March 1, 2021, 8:43 p.m. |
| From Russia with Love | 100 | March 1, 2021, 6:58 p.m. |
| Unusual encryption using a diophantine equation | 1,084 | Feb. 24, 2021, 2 p.m. |
| Double Columnar Transposition | 100 | Feb. 21, 2021, 8:07 p.m. |
| Classical Ciphers^3 | 100 | Feb. 19, 2021, 9:55 a.m. |
| Find the right route — Part 1 | 101 | Feb. 18, 2021, 2:15 p.m. |
| One-Time Pad with Flaws | 100 | Feb. 17, 2021, 9:54 p.m. |
| Monoalphabetic substitution with camouflage — Part 4 | 100 | Feb. 17, 2021, 2:53 p.m. |
| Monoalphabetic substitution with camouflage — Part 3 | 1,085 | Feb. 4, 2021, 12:24 p.m. |
| Modified Caesar Cipher | 100 | Feb. 4, 2021, 6:51 a.m. |
| Monoalphabetic substitution with camouflage — Part 2 | 1,085 | Jan. 30, 2021, 8:09 a.m. |
| Monoalphabetic substitution with camouflage — Part 1 | 100 | Jan. 23, 2021, 10:03 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,146 | June 7, 2020, 8:54 p.m. |
| Advent-Challenge — Part 1 | 100 | May 24, 2020, 1:22 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | May 24, 2020, 1:11 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | May 23, 2020, 7:06 p.m. |
| Grille Cipher | 100 | May 23, 2020, 12:31 p.m. |
| Factorization Cipher — Part 1 | 100 | May 23, 2020, 7:37 a.m. |
| Cracking SHA1-Hashed Passwords | 1,085 | May 21, 2020, 4:18 p.m. |
| Monoalphabetic Substitution | 100 | June 2, 2019, 8:31 a.m. |
| Letter to the Templars — Part 3 | 1,093 | June 1, 2019, 10:15 p.m. |
| Letter to the Templars — Part 2 | 100 | June 1, 2019, 9:46 p.m. |
| Letter to the Templars — Part 1 | 100 | June 1, 2019, 5:57 p.m. |
| Beaver Code | 100 | June 1, 2019, 4:44 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | June 1, 2019, 8:38 a.m. |
| Caesar Encryption | 100 | May 31, 2019, 8:53 p.m. |
| Number Sequence — Part 8 | 100 | May 31, 2019, 7:19 p.m. |
| Number Sequence — Part 6 | 100 | May 31, 2019, 7:13 p.m. |
| Number Sequence — Part 9 | 100 | May 31, 2019, 7 p.m. |
| Number Sequence — Part 4 | 100 | May 29, 2019, 1:05 p.m. |
| Number Sequence — Part 3 | 100 | May 29, 2019, 12:57 p.m. |
| Number Sequence — Part 2 | 100 | May 29, 2019, 6:59 a.m. |
| Number Sequence | 100 | May 28, 2019, 9:20 p.m. |
| A hidden word | 100 | April 11, 2019, 10:01 a.m. |
| Original Caesar Cipher | 100 | March 15, 2019, 10:47 p.m. |
| Autokey Cipher | 101 | March 15, 2019, 10:17 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 102 | March 11, 2019, 3:41 p.m. |
Gold0
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Bronze0
