| Enigma Part 1 | 1,083 | Nov. 20, 2020, 3:06 a.m. |
| Summer Job | 1,122 | Nov. 14, 2020, 8:15 p.m. |
| Turing Bombe Enigma I | 100 | Nov. 13, 2020, 8:49 p.m. |
| Hill Cipher with Sudoku Key | 100 | Nov. 5, 2020, 2:24 p.m. |
| Zodiac Cipher | 100 | Nov. 3, 2020, 3:01 p.m. |
| Homophonic Encryption — Part 1 | 1,140 | Nov. 2, 2020, 11:57 p.m. |
| Homophonic Encryption — Part 2 | 1,140 | Nov. 2, 2020, 11:44 p.m. |
| Homophonic Encryption — Part 4 | 1,140 | Nov. 2, 2020, 9:47 p.m. |
| Homophonic Encryption — Part 3 | 1,140 | Nov. 2, 2020, 7:28 p.m. |
| Polyhomophonic Substitution — Part 1 | 100 | Nov. 2, 2020, 12:39 a.m. |
| CMEA 1 | 1,083 | Oct. 29, 2020, 4:22 p.m. |
| RSA: Two different keys — same ciphertext | 1,085 | Oct. 28, 2020, 10:13 p.m. |
| Find the right route — Part 1 | 200 | Oct. 28, 2020, 1:45 a.m. |
| Advent Challenge — Part 4 | 1,117 | Oct. 27, 2020, 12:56 p.m. |
| Advent Challenge — Part 3 | 1,117 | Oct. 25, 2020, 1:45 p.m. |
| Advent-Challenge — Part 2 | 1,117 | Oct. 25, 2020, 1:43 a.m. |
| Lightweight Introduction to Lattices — Part 3 | 1,406 | Aug. 1, 2020, 5:46 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 103 | July 31, 2020, 10:25 p.m. |
| Lightweight Introduction to Lattices — Part 1 | 101 | July 29, 2020, 6:43 p.m. |
| Factorization Cipher — Part 2 | 1,086 | July 24, 2020, 3:54 p.m. |
| M-138 — Part 2 | 1,099 | March 3, 2020, 12:01 a.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 1,613 | Feb. 24, 2020, 5:03 p.m. |
| Strange Message from Thessaloniki | 100 | Feb. 23, 2020, 11:37 p.m. |
| New Year's Greetings — Part 5 | 1,107 | Feb. 18, 2020, 12:58 a.m. |
| New Year's Greetings — Part 4 | 100 | Feb. 17, 2020, midnight |
| New Year's Greetings — Part 3 | 100 | Feb. 16, 2020, 10:10 p.m. |
| New Year's Greetings — Part 2 | 100 | Feb. 16, 2020, 8:23 p.m. |
| News from Castle Mansfeld | 100 | Feb. 16, 2020, 2:21 a.m. |
| New Year's Greetings — Part 1 | 100 | Feb. 14, 2020, 10:01 p.m. |
| From Russia with Love | 100 | Feb. 14, 2020, 12:54 a.m. |
| ¿No Hablas Español? No problemo! | 100 | Feb. 13, 2020, 10:18 p.m. |
| The Last Note | 100 | Feb. 13, 2020, 7:43 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Feb. 12, 2020, 11:28 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Feb. 12, 2020, 8:54 p.m. |
| Double Columnar Transposition | 100 | Feb. 9, 2020, 2 a.m. |
| Multilingual Monoalphabetic Substitution | 100 | Feb. 2, 2020, 11:16 p.m. |
| Monoalphabetic Substitution with Nostradamus Flavor | 1,160 | Jan. 29, 2020, 11:02 p.m. |
| The Einstein Enigma | 1,130 | Jan. 28, 2020, 10:46 p.m. |
| Classical Ciphers^3 | 100 | Jan. 12, 2020, 10:18 p.m. |
| Enigma Messages | 100 | Nov. 25, 2019, 3:07 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Nov. 24, 2019, 7:44 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | Nov. 24, 2019, 1:35 a.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Nov. 23, 2019, 5:48 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | Nov. 23, 2019, 2:45 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Nov. 23, 2019, 12:52 a.m. |
| Number Sequence — Part 6 | 100 | Nov. 19, 2019, 4:31 p.m. |
| A really long number sequence | 1,087 | Nov. 17, 2019, 12:51 a.m. |
| Pigpen with a twist — Part 1 | 100 | Nov. 15, 2019, 8:54 p.m. |
| M-138 — Part 1 | 100 | Nov. 13, 2019, 12:33 a.m. |
| Reserve Hand Procedure — Part 1 | 100 | Nov. 11, 2019, 5:58 p.m. |
| How do you become a big cryptographer? | 100 | Nov. 10, 2019, 4:52 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,087 | Nov. 9, 2019, 4:28 p.m. |
| Alice's Birthday Party (Part 1) | 1,085 | Nov. 9, 2019, 2:35 a.m. |
| Alice's Birthday Party (Part 2) | 1,085 | Nov. 9, 2019, 1:39 a.m. |
| One-Time Pad with Flaws | 100 | Nov. 2, 2019, 12:41 a.m. |
| Number Sequence — Part 8 | 100 | Oct. 29, 2019, 12:50 p.m. |
| Advent-Challenge — Part 1 | 100 | Oct. 29, 2019, midnight |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Oct. 27, 2019, 11:01 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Oct. 27, 2019, 8:27 p.m. |
| Grille Cipher | 100 | Oct. 25, 2019, 10:35 p.m. |
| Cracking SHA1-Hashed Passwords | 1,086 | Oct. 25, 2019, 8:54 p.m. |
| Number Sequence — Part 3 | 100 | Oct. 23, 2019, 3:07 a.m. |
| A hidden word | 100 | Oct. 21, 2019, 12:54 a.m. |
| Number Sequence — Part 4 | 100 | Oct. 21, 2019, 12:32 a.m. |
| Caesar Encryption | 100 | Oct. 19, 2019, 4:18 p.m. |
| Number Sequence — Part 2 | 100 | Oct. 19, 2019, 3:29 p.m. |
| Original Caesar Cipher | 100 | Oct. 19, 2019, 3:20 p.m. |
| Number Sequence | 100 | Oct. 19, 2019, 2:35 p.m. |
| Letter to the Templars — Part 3 | 1,091 | Oct. 18, 2019, 9:42 p.m. |
| Letter to the Templars — Part 2 | 100 | Oct. 18, 2019, 8:11 p.m. |
| Letter to the Templars — Part 1 | 100 | Oct. 18, 2019, 7:58 p.m. |
| Beaver Code | 100 | Oct. 18, 2019, 5:58 p.m. |
| Unusual encryption using a diophantine equation | 1,088 | Oct. 10, 2019, 12:38 a.m. |
| Recycled One-Time Pad | 100 | Oct. 9, 2019, 2:27 p.m. |
| Factorization Cipher — Part 1 | 100 | Oct. 5, 2019, 3 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Oct. 4, 2019, 4:29 p.m. |
| Autokey Cipher | 100 | Oct. 2, 2019, 3:14 p.m. |
| Modular Sequences | 100 | Sept. 24, 2019, 5:50 p.m. |
| Number Sequence — Part 10 | 100 | Sept. 24, 2019, 3:37 p.m. |