| Number Sequence — Part 9 | 100 | Oct. 17, 2020, 10:16 p.m. |
| Autokey Cipher | 100 | Oct. 17, 2020, 9:38 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 101 | Oct. 17, 2020, 6:47 p.m. |
| Lightweight Introduction to Lattices — Part 1 | 101 | Oct. 17, 2020, 6:03 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 100 | Oct. 16, 2020, 10:32 p.m. |
| Polyhomophonic Substitution — Part 1 | 100 | Oct. 16, 2020, 7:24 p.m. |
| ORYX Stream Cipher — Part 3 (revised) | 1,096 | April 16, 2019, 10:28 a.m. |
| ORYX Stream Cipher Part II | 1,087 | April 12, 2019, 5:31 p.m. |
| ORYX Stream Cipher Part I | 1,087 | April 12, 2019, 4:03 p.m. |
| Playfair Encryption | 100 | April 10, 2019, 12:36 p.m. |
| Unusual encryption using a diophantine equation | 1,089 | April 4, 2019, 4:16 p.m. |
| Hybrid Encryption I | 1,087 | April 4, 2019, 3:02 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,087 | April 3, 2019, 6:31 p.m. |
| Modified Caesar Cipher | 100 | April 3, 2019, 4:48 p.m. |
| From Russia with Love | 100 | April 3, 2019, 3:56 p.m. |
| Snow White and the seven dwarfs | 100 | April 3, 2019, 2:43 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | April 3, 2019, 1:16 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | April 3, 2019, 12:38 p.m. |
| Number Sequence — Part 8 | 100 | April 3, 2019, 11:42 a.m. |
| One-Time Pad with Flaws | 100 | April 2, 2019, 5:54 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | April 2, 2019, 5:03 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,091 | April 2, 2019, 4:31 p.m. |
| Unconcealed RSA messages | 1,090 | April 2, 2019, 1:24 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,089 | April 1, 2019, 4:13 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,087 | April 1, 2019, 2:11 p.m. |
| RSA: Two different keys — same ciphertext | 1,089 | March 29, 2019, 12:57 p.m. |
| Letter to the Templars — Part 3 | 1,093 | March 29, 2019, 10:37 a.m. |
| Grille Cipher | 100 | March 28, 2019, 12:14 a.m. |
| Cracking SHA1-Hashed Passwords | 1,088 | March 27, 2019, 11:55 p.m. |
| Original Caesar Cipher | 100 | March 27, 2019, 11:50 p.m. |
| Factorization Cipher — Part 2 | 1,090 | March 27, 2019, 11:41 p.m. |
| Beaver Code | 100 | March 27, 2019, 5:13 p.m. |
| Number Sequence — Part 4 | 100 | March 27, 2019, 4:38 p.m. |
| Number Sequence — Part 3 | 100 | March 27, 2019, 4:21 p.m. |
| Number Sequence — Part 2 | 100 | March 27, 2019, 4:13 p.m. |
| Caesar Encryption | 100 | March 27, 2019, 4:07 p.m. |
| Letter to the Templars — Part 2 | 100 | March 26, 2019, 5:28 p.m. |
| Letter to the Templars — Part 1 | 100 | March 26, 2019, 5:09 p.m. |
| Factorization Cipher — Part 1 | 100 | March 26, 2019, 4:21 p.m. |
| Factorization Cipher — Part 3 | 1,090 | March 26, 2019, 4:15 p.m. |
| Alice's Birthday Party (Part 2) | 1,087 | March 21, 2019, 12:09 p.m. |
| Alice's Birthday Party (Part 1) | 1,087 | March 20, 2019, 3:14 p.m. |
| Modular Sequences | 101 | March 19, 2019, 4:35 p.m. |
| Hill Cipher with Sudoku Key | 100 | March 19, 2019, 3:36 p.m. |
| Playfair with hints about the grid | 100 | March 14, 2019, 6:49 p.m. |
| Number Sequence — Part 10 | 100 | March 14, 2019, 12:05 p.m. |
| A hidden word | 100 | March 14, 2019, 10:50 a.m. |
| Advent-Challenge — Part 1 | 100 | March 14, 2019, 9:42 a.m. |
| Number Sequence | 100 | March 13, 2019, 5:28 p.m. |
| Monoalphabetic Substitution | 100 | March 13, 2019, 5:21 p.m. |
| Classical Ciphers^3 | 100 | March 13, 2019, 4:36 p.m. |
| How do you become a big cryptographer? | 100 | March 8, 2019, 4:53 p.m. |