| BCR code (Book-Caesar-RSA) | 1,203 | Feb. 11, 2013, 1:45 a.m. |
| Smartcard RSA | 1,146 | Feb. 14, 2012, 10:03 p.m. |
| Factorization Cipher — Part 2 | 1,268 | Feb. 1, 2012, 1:06 p.m. |
| Factorization Cipher — Part 1 | 101 | Jan. 31, 2012, 12:58 a.m. |
| ORYX Stream Cipher Part I | 1,150 | Dec. 18, 2011, 9:28 p.m. |
| Modified Caesar Cipher | 104 | Sept. 28, 2011, 8:47 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Sept. 13, 2011, 11:14 p.m. |
| Number Sequence — Part 2 | 102 | Sept. 13, 2011, 2:06 a.m. |
| Pigpen with a twist — Part 1 | 113 | Sept. 13, 2011, 12:36 a.m. |
| A really long number sequence | 1,660 | Sept. 9, 2011, 12:58 p.m. |
| RSA: Two different keys — same ciphertext | 1,523 | Aug. 22, 2011, 10:54 p.m. |
| Alice's Birthday Party (Part 2) | 1,164 | Aug. 22, 2011, 8:19 p.m. |
| Alice's Birthday Party (Part 1) | 1,164 | Aug. 22, 2011, 7:19 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,165 | Aug. 21, 2011, 7:50 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,337 | Aug. 21, 2011, 2 p.m. |
| Cracking SHA1-Hashed Passwords | 1,210 | Aug. 19, 2011, 8:16 p.m. |
| Monoalphabetic Substitution | 100 | Aug. 19, 2011, 7:07 p.m. |