| Modified Caesar Cipher | 100 | Oct. 18, 2020, 1:22 a.m. |
| M-138 — Part 2 | 1,096 | Oct. 16, 2020, 5:34 p.m. |
| M-138 — Part 1 | 100 | Oct. 16, 2020, 4:36 p.m. |
| Original Caesar Cipher | 100 | Oct. 15, 2020, 8:04 p.m. |
| Number Sequence — Part 8 | 100 | Oct. 15, 2020, 7:55 p.m. |
| Letter to the Templars — Part 3 | 1,088 | Oct. 15, 2020, 7:40 p.m. |
| Letter to the Templars — Part 2 | 100 | Oct. 15, 2020, 4:48 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Sept. 23, 2020, 2:38 a.m. |
| Caesar Encryption | 100 | Sept. 21, 2020, 2:06 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Sept. 21, 2020, 1:01 p.m. |
| Advent Challenge — Part 3 | 1,118 | Sept. 21, 2020, 11:12 a.m. |
| Advent-Challenge — Part 2 | 1,118 | Sept. 21, 2020, 11:03 a.m. |
| Advent-Challenge — Part 1 | 100 | Sept. 21, 2020, 10:05 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Aug. 19, 2020, 12:37 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Aug. 10, 2020, 2:43 p.m. |
| Beaver Code | 100 | May 7, 2020, 1:01 p.m. |
| Number Sequence | 100 | May 7, 2020, 12:50 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,088 | March 1, 2020, 4:23 p.m. |
| A hidden word | 100 | March 1, 2020, 4:11 p.m. |
| Factorization Cipher — Part 1 | 100 | March 1, 2020, 3:26 a.m. |
| RSA: Two different keys — same ciphertext | 1,086 | Feb. 24, 2020, 3:12 p.m. |
| Hybrid Encryption I | 1,084 | Feb. 24, 2020, 2:40 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,084 | Feb. 24, 2020, 2:23 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,086 | Feb. 24, 2020, 12:40 p.m. |
| Alice's Birthday Party (Part 2) | 1,084 | Feb. 23, 2020, 9:28 p.m. |
| Cracking SHA1-Hashed Passwords | 1,085 | Feb. 23, 2020, 9:06 p.m. |
| Alice's Birthday Party (Part 1) | 1,084 | Feb. 23, 2020, 9:03 p.m. |
| Letter to the Templars — Part 1 | 100 | Jan. 27, 2020, 5:10 p.m. |
| Number Sequence — Part 2 | 100 | Jan. 27, 2020, 5 p.m. |