| Polyphonic Substitution Cipher — Part 1 | 1,349 | Dec. 18, 2019, 12:49 a.m. |
| ADFGVX — Part 2 | 100 | Oct. 18, 2019, 6:32 p.m. |
| ADFGVX — Part 1 | 100 | Oct. 18, 2019, 1:20 p.m. |
| Kaskade-S/T — Part 1 | 100 | Oct. 15, 2019, 11:10 p.m. |
| Nils away on travel | 100 | Oct. 15, 2019, 10:49 a.m. |
| Number Sequence — Part 7 | 100 | Oct. 9, 2019, 6:22 p.m. |
| Modular Sequences | 100 | Oct. 9, 2019, 5:33 p.m. |
| Trifid Cipher | 100 | Oct. 6, 2019, 10:30 a.m. |
| Homophonic Encryption — Part 4 | 1,207 | Sept. 28, 2019, 11:53 p.m. |
| ¿No Hablas Español? No problemo! | 100 | Sept. 28, 2019, 8:27 p.m. |
| Spanish Strip Cipher — Part 2 | 1,097 | Sept. 28, 2019, 6:07 p.m. |
| Spanish Strip Cipher — Part 1 | 1,097 | Sept. 25, 2019, 5:50 p.m. |
| Unusual encryption using a diophantine equation | 1,088 | Aug. 18, 2019, 10:28 p.m. |
| Cryptanalysis Hacking Puzzles — Part 2 | 101 | June 19, 2019, 1:17 p.m. |
| Autokey Cipher | 100 | June 19, 2019, 12:01 p.m. |
| Homophonic Encryption — Part 3 | 1,312 | June 15, 2019, 9:29 a.m. |
| Homophonic Encryption — Part 2 | 1,423 | May 22, 2019, 9:56 p.m. |
| Homophonic Encryption — Part 1 | 1,391 | May 22, 2019, 5:04 p.m. |
| Handycipher made in love — Part 2 | 2,000 | May 22, 2019, 12:46 p.m. |
| Handycipher made in love — Part 1 | 1,236 | May 19, 2019, 10:53 p.m. |
| Weakened Handycipher — Part 3 | 1,106 | May 8, 2019, 4:05 p.m. |
| Weakened Handycipher — Part 2 | 1,107 | May 6, 2019, 6:37 p.m. |
| Weakened Handycipher — Part 1 | 1,107 | May 2, 2019, 9:21 a.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | March 24, 2019, 4:10 p.m. |
| Number Sequence — Part 6 | 100 | March 24, 2019, 3:11 p.m. |
| Number Sequence — Part 9 | 100 | March 24, 2019, 3:04 p.m. |
| The Einstein Enigma | 1,190 | Aug. 18, 2018, 10:44 p.m. |
| Number Sequence — Part 10 | 102 | May 31, 2018, 12:56 p.m. |
| M-138 — Part 3 | 1,113 | March 22, 2018, 7:37 p.m. |
| Molehunt (Part 3/3) | 1,090 | March 21, 2018, 12:41 a.m. |
| Molehunt (Part 1/3) | 100 | March 11, 2018, 11:53 p.m. |
| Molehunt (Part 2/3) | 100 | March 11, 2018, 10:45 a.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | March 2, 2018, 11:01 p.m. |
| Heartbleed — Part 1 | 100 | Feb. 28, 2018, 5:26 p.m. |
| Advent-Challenge — Part 1 | 101 | Feb. 27, 2018, 12:14 p.m. |
| Double Column Transposition — Part 3 | 1,112 | Aug. 27, 2017, 10:41 p.m. |
| Double Column Transposition — Part 4 | 1,112 | Aug. 27, 2017, 1:12 p.m. |
| Double Column Transposition — Part 2 | 1,112 | Aug. 20, 2017, 9:28 p.m. |
| Weakened Granit — Part 1 | 100 | Aug. 8, 2017, 12:04 a.m. |
| Double Columnar Transposition | 100 | Aug. 6, 2017, 4:03 p.m. |
| The Last Note | 100 | Aug. 2, 2017, 9:21 p.m. |
| M-138 — Part 2 | 1,123 | May 17, 2017, 5:39 p.m. |
| M-138 — Part 1 | 100 | May 16, 2017, 12:28 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | April 27, 2017, 11:51 a.m. |
| A Secret Message from Castle Mansfeld | 100 | April 25, 2017, 2:16 p.m. |
| Classical Ciphers^3 | 100 | April 24, 2017, 9:02 a.m. |
| Zodiac Cipher | 100 | April 23, 2017, 8:28 p.m. |
| ASAC — A Strong(er) ADFGVX Cipher — Part 1 | 1,179 | Feb. 26, 2017, 6:09 p.m. |
| Number Sequence — Part 8 | 100 | Feb. 21, 2017, 6:03 p.m. |
| A hidden word | 100 | Feb. 21, 2017, 2:19 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,104 | Feb. 17, 2015, 2:11 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,110 | Feb. 15, 2015, 8:25 p.m. |
| Alice's Birthday Party (Part 2) | 1,104 | Feb. 15, 2015, 4:16 p.m. |
| Alice's Birthday Party (Part 1) | 1,104 | Feb. 15, 2015, 1:30 p.m. |
| Cracking SHA1-Hashed Passwords | 1,108 | Feb. 7, 2015, 4:24 p.m. |
| Factorization Cipher — Part 2 | 1,113 | Feb. 2, 2015, 8:33 p.m. |
| Pigpen with a twist — Part 1 | 100 | Jan. 20, 2015, 8:33 p.m. |
| From Russia with Love | 100 | Jan. 20, 2015, 1:30 a.m. |
| How do you become a big cryptographer? | 100 | Jan. 20, 2015, 12:03 a.m. |
| Playfair with hints about the grid | 100 | Jan. 15, 2015, 9:09 p.m. |
| Factorization Cipher — Part 3 | 1,115 | Jan. 12, 2015, 8:27 p.m. |
| Modified Caesar Cipher | 100 | Jan. 8, 2015, 2:46 p.m. |
| Reserve Hand Procedure — Part 1 | 100 | Jan. 7, 2015, 1:55 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Jan. 5, 2015, 7:30 p.m. |
| One-Time Pad with Flaws | 100 | Jan. 4, 2015, 11:38 p.m. |
| Grille Cipher | 100 | Jan. 4, 2015, 12:31 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Jan. 4, 2015, 12:55 a.m. |
| Factorization Cipher — Part 1 | 100 | Dec. 31, 2014, 1:16 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Dec. 29, 2014, 11:53 a.m. |
| Number Sequence — Part 4 | 100 | Dec. 28, 2014, 1:43 p.m. |
| Number Sequence — Part 3 | 100 | Dec. 28, 2014, 1:40 p.m. |
| Letter to the Templars — Part 3 | 1,125 | Dec. 28, 2014, 10:31 a.m. |
| Letter to the Templars — Part 2 | 100 | Dec. 28, 2014, 10:18 a.m. |
| Monoalphabetic Substitution | 100 | Dec. 28, 2014, 10:02 a.m. |
| Letter to the Templars — Part 1 | 100 | Dec. 27, 2014, 6:17 p.m. |
| Beaver Code | 100 | Dec. 27, 2014, 1:53 p.m. |
| Playfair Encryption | 100 | Dec. 27, 2014, 10:33 a.m. |
| Caesar Encryption | 100 | Dec. 26, 2014, 11:30 p.m. |
| Number Sequence — Part 2 | 100 | Dec. 26, 2014, 7:18 p.m. |
| Original Caesar Cipher | 100 | Dec. 26, 2014, 7:16 p.m. |
| Number Sequence | 100 | Dec. 26, 2014, 7:12 p.m. |