| Cryptanalysis Hacking Puzzles — Part 2 | 100 | Jan. 14, 2023, 7:14 p.m. |
| RSA Factoring Challenge: RSA-250 | 0 | April 14, 2020, 9:48 a.m. |
| RSA Factoring Challenge: RSA-240 | 0 | April 14, 2020, 9:46 a.m. |
| RSA Factoring Challenge: RSA-232 | 0 | April 14, 2020, 9:43 a.m. |
| A hidden word | 100 | Aug. 10, 2019, 4:27 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Aug. 10, 2019, 4:17 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,087 | Feb. 16, 2019, 11:28 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,089 | Feb. 16, 2019, 11:16 a.m. |
| Alice's Birthday Party (Part 2) | 1,087 | Feb. 16, 2019, 10:59 a.m. |
| Number Sequence — Part 8 | 100 | Feb. 15, 2019, 10:03 p.m. |
| From Russia with Love | 100 | Feb. 15, 2019, 10 p.m. |
| Alice's Birthday Party (Part 1) | 1,087 | Feb. 15, 2019, 9:03 p.m. |
| One-Time Pad with Flaws | 100 | Feb. 15, 2019, 8:14 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Feb. 15, 2019, 7:43 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Feb. 15, 2019, 7:31 p.m. |
| Grille Cipher | 100 | Feb. 15, 2019, 6:55 p.m. |
| Factorization Cipher — Part 1 | 100 | Feb. 14, 2019, 11:40 p.m. |
| Cracking SHA1-Hashed Passwords | 1,088 | Feb. 14, 2019, 11:25 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Feb. 14, 2019, 11:21 p.m. |
| Beaver Code | 100 | Feb. 14, 2019, 10:56 p.m. |
| Letter to the Templars — Part 3 | 1,094 | Feb. 14, 2019, 10:43 p.m. |
| Letter to the Templars — Part 2 | 100 | Feb. 14, 2019, 10:34 p.m. |
| Original Caesar Cipher | 100 | Feb. 14, 2019, 10:29 p.m. |
| Letter to the Templars — Part 1 | 100 | Feb. 14, 2019, 10:25 p.m. |
| Caesar Encryption | 100 | Oct. 24, 2018, 6:23 p.m. |
| Number Sequence — Part 5 | 100 | Oct. 20, 2018, 1:12 p.m. |
| Number Sequence — Part 4 | 100 | Oct. 20, 2018, 1 p.m. |
| Number Sequence — Part 3 | 100 | Oct. 20, 2018, 12:57 p.m. |
| Advent-Challenge — Part 1 | 100 | Oct. 20, 2018, 12:13 p.m. |
| Number Sequence — Part 2 | 100 | July 5, 2013, 1:40 p.m. |
| Number Sequence | 100 | July 5, 2013, 1:33 p.m. |