| ¿No Hablas Español? No problemo! | 100 | March 14, 2017, 8:20 p.m. |
| How do you become a big cryptographer? | 100 | March 14, 2017, 8:06 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,140 | Aug. 8, 2013, 3:49 p.m. |
| Nils away on travel | 200 | Aug. 8, 2013, 3:30 p.m. |
| A hidden word | 104 | Jan. 30, 2013, 11:05 a.m. |
| Beaver Code | 111 | Aug. 22, 2012, 9:14 a.m. |
| ECDH-Key Exchange for Beginners | 120 | Feb. 28, 2012, 11:48 p.m. |
| Factorization Cipher — Part 1 | 200 | Oct. 18, 2011, 12:25 a.m. |
| Grille Cipher | 200 | Oct. 14, 2011, 6:18 p.m. |
| A really long number sequence | 1,378 | Sept. 26, 2011, 1:42 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 200 | Sept. 9, 2011, 12:12 p.m. |
| Unusual encryption using a diophantine equation | 2,000 | Sept. 2, 2011, 5:57 p.m. |
| Modified Caesar Cipher | 200 | Sept. 2, 2011, 4:25 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,164 | Aug. 25, 2011, 12:50 a.m. |
| Cracking SHA1-Hashed Passwords | 1,208 | Aug. 23, 2011, 10:14 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,182 | Aug. 22, 2011, 11:41 p.m. |
| ORYX Stream Cipher Part I | 1,165 | Aug. 22, 2011, 12:54 a.m. |
| Smartcard RSA | 1,167 | Aug. 18, 2011, 9:43 p.m. |
| ADFGVX — Part 1 | 200 | Aug. 16, 2011, 12:59 a.m. |
| ADFGVX — Part 2 | 200 | Aug. 15, 2011, 11:37 p.m. |
| RSA: Two different keys — same ciphertext | 2,000 | Aug. 15, 2011, 7:34 p.m. |
| Enigma Part 1 | 1,166 | Aug. 13, 2011, 4:46 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,166 | Aug. 13, 2011, 1:08 p.m. |
| Lattice Part 1 | 1,202 | Aug. 12, 2011, 10:21 p.m. |
| Enigma Part 2 | 1,167 | Aug. 9, 2011, 7:18 p.m. |
| Hybrid Encryption I | 1,170 | Aug. 9, 2011, 2:58 p.m. |
| Zodiac Cipher | 100 | Aug. 1, 2011, 10:15 p.m. |
| A Secret Message from Castle Mansfeld | 100 | Aug. 1, 2011, 12:45 p.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | July 31, 2011, 3:36 p.m. |
| Molehunt (Part 3/3) | 1,170 | July 31, 2011, 2:43 p.m. |
| Molehunt (Part 2/3) | 100 | July 31, 2011, 1:44 p.m. |
| Molehunt (Part 1/3) | 100 | July 31, 2011, 12:24 p.m. |
| Music Code — Part 2 | 1,251 | July 31, 2011, 11:43 a.m. |
| Playfair Encryption | 100 | July 31, 2011, 11:19 a.m. |
| Not-so-Secret Message from Malawi — Part II (ECC) | 1,169 | July 28, 2011, 1 p.m. |
| Kaskade-S/T — Part 1 | 101 | July 24, 2011, 1:35 a.m. |
| Broadcasting and low exponent — RSA Attack | 2,000 | July 22, 2011, 8:34 p.m. |
| Music Code — Part 1 | 102 | July 17, 2011, 6:27 p.m. |
| Monoalphabetic Substitution | 100 | July 15, 2011, 12:05 p.m. |
| Number Sequence — Part 2 | 150 | July 12, 2011, 5:36 p.m. |
| Enigma Combinatorics | 100 | June 29, 2011, 1:59 p.m. |
| Classical Ciphers^3 | 100 | June 27, 2011, 11:50 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 101 | June 23, 2011, 2:34 p.m. |
| One-Time Pad with Flaws | 100 | June 21, 2011, 11:16 a.m. |
| Alice's Birthday Party (Part 2) | 1,176 | June 20, 2011, 3:29 p.m. |
| Alice's Birthday Party (Part 1) | 1,176 | June 20, 2011, 2:53 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | June 20, 2011, 12:51 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | June 20, 2011, 12:38 p.m. |
| Number Sequence | 100 | June 18, 2011, 3:39 p.m. |
| Caesar Encryption | 100 | June 18, 2011, 3:37 p.m. |
| Original Caesar Cipher | 101 | June 18, 2011, 2:15 p.m. |