| Cryptanalysis Hacking Puzzles — Part 2 | 100 | May 27, 2023, 5:43 a.m. |
| The Hutton Cipher – Part 1 | 1,378 | May 23, 2023, 2:15 a.m. |
| A hidden word — Part 2 | 100 | April 19, 2023, 10:33 p.m. |
| Autokey Cipher | 100 | April 19, 2023, 6:52 p.m. |
| Merkle-Hellman Knapsack Challenge - Part 1 | 101 | April 18, 2023, 5:28 p.m. |
| The Syllabary Cipher – Part 5 | 1,414 | Nov. 12, 2022, 11:58 p.m. |
| The Syllabary Cipher – Part 4 | 1,414 | Nov. 12, 2022, 6:45 p.m. |
| The Syllabary Cipher – Part 3 | 1,414 | Nov. 12, 2022, 5:05 p.m. |
| The Syllabary Cipher – Part 2 | 1,444 | Nov. 9, 2022, 8:09 p.m. |
| The Syllabary Cipher – Part 1 | 111 | Nov. 5, 2022, 5:47 p.m. |
| CMEA 2 | 13,018 | Nov. 3, 2022, 2:37 p.m. |
| CMEA 1 | 1,079 | Oct. 30, 2022, 5:50 p.m. |
| Polyhomophonic Substitution — Part 1 | 100 | Oct. 19, 2022, 5:07 p.m. |
| Lightweight Introduction to Lattices — Part 2 | 100 | Oct. 17, 2022, 4:47 p.m. |
| Lightweight Introduction to Lattices — Part 1 | 100 | Oct. 16, 2022, 5:32 p.m. |
| Alberti Challenge — Part 1 | 101 | Sept. 22, 2022, 11:46 p.m. |
| The LoRa Cipher: Logic Randomness — Part 1 | 1,133 | Dec. 16, 2021, 12:01 a.m. |
| The Einstein Enigma | 1,108 | Nov. 20, 2021, 6:30 p.m. |
| Fastest in the West | 1,111 | Nov. 11, 2021, 11:45 p.m. |
| Find the right route — Part 1 | 100 | Oct. 6, 2021, 8:16 p.m. |
| Wheatstone Cryptograph — Part 1 | 103 | May 24, 2021, 5:25 p.m. |
| Summer Job | 1,116 | May 23, 2021, 7:22 p.m. |
| AES ECB Wrong Encoding | 1,112 | April 14, 2021, 6:27 p.m. |
| Advent-Challenge — Part 2 | 1,115 | Dec. 22, 2020, 7:24 p.m. |
| Advent Challenge — Part 4 | 1,116 | Dec. 9, 2020, 4:49 p.m. |
| Advent Challenge — Part 3 | 1,116 | Dec. 8, 2020, 3:48 a.m. |
| Advent-Challenge — Part 1 | 100 | Dec. 5, 2020, 5:11 p.m. |
| A hidden word | 100 | Oct. 19, 2018, 4:21 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,096 | Nov. 17, 2016, 1:56 a.m. |
| Number Sequence — Part 4 | 100 | Nov. 11, 2016, 10:03 p.m. |
| Image Noise | 109 | Dec. 1, 2015, 6:39 p.m. |
| Keyshanc — Part 2 | 1,111 | Oct. 9, 2015, 10:45 p.m. |
| Keyshanc — Part 1 | 1,111 | Oct. 9, 2015, 4:31 p.m. |
| Enigma Part 2 | 1,100 | Oct. 5, 2015, 5:40 p.m. |
| Number Sequence — Part 8 | 108 | Sept. 26, 2015, 11:32 p.m. |
| Enigma Part 1 | 1,100 | Sept. 25, 2015, 2:20 p.m. |
| Typex — Part 2 | 1,122 | Sept. 24, 2015, 8:42 p.m. |
| Typex — Part 1 | 1,120 | Sept. 22, 2015, 12:54 p.m. |
| ECDH-Key Exchange for Beginners | 100 | Sept. 18, 2015, 8:13 p.m. |
| Enigma Combinatorics | 100 | Sept. 18, 2015, 6:40 p.m. |
| Nils away on travel | 100 | Sept. 18, 2015, 4:28 p.m. |
| Turing Bombe Enigma I | 100 | Sept. 18, 2015, 3:39 p.m. |
| Enigma Messages with Repeated Letters — Part 5 | 100 | Sept. 13, 2015, 6:32 p.m. |
| Enigma Messages with Repeated Letters — Part 4 | 100 | Sept. 13, 2015, 6:04 p.m. |
| Enigma Messages with Repeated Letters — Part 3 | 100 | Sept. 13, 2015, 3:37 p.m. |
| Enigma Messages | 100 | Sept. 13, 2015, 3:08 p.m. |
| Enigma Messages with Repeated Letters — Part 2 | 100 | Sept. 13, 2015, 2:26 p.m. |
| Double Column Transposition — Part 3 | 1,144 | Sept. 6, 2015, 1:29 a.m. |
| Double Column Transposition — Part 4 | 1,146 | Sept. 3, 2015, 8:23 p.m. |
| Double Column Transposition — Part 2 | 1,145 | Sept. 2, 2015, 7:04 p.m. |
| AES key — encoded in the machine readable zone of a European ePassport | 1,110 | Aug. 15, 2015, 1:14 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,110 | Aug. 12, 2015, 3:45 p.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | March 18, 2015, 4:38 p.m. |
| Heartbleed — Part 2 | 100 | March 17, 2015, 5:47 p.m. |
| Heartbleed — Part 1 | 100 | March 17, 2015, 5:18 p.m. |
| ORYX Stream Cipher — Part 3 (revised) | 1,134 | March 6, 2015, 5:02 p.m. |
| ORYX Stream Cipher Part II | 1,104 | March 2, 2015, 4:16 p.m. |
| ORYX Stream Cipher Part I | 1,104 | March 1, 2015, 11:18 p.m. |
| M-138 — Part 4 | 1,264 | Feb. 26, 2015, 5:40 p.m. |
| M-138 — Part 3 | 1,283 | Feb. 13, 2015, 3:09 a.m. |
| ¿No Hablas Español? No problemo! | 100 | Feb. 12, 2015, 11:43 p.m. |
| Trifid Cipher | 100 | Feb. 12, 2015, 6:12 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | Jan. 29, 2015, 1:06 a.m. |
| Hybrid Encryption I | 1,105 | Jan. 27, 2015, 5:58 p.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,104 | Jan. 27, 2015, 1:19 a.m. |
| Recycled One-Time Pad | 100 | Jan. 21, 2015, 4:50 a.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Jan. 20, 2015, 10:31 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Jan. 20, 2015, 8:42 p.m. |
| Alice's Birthday Party (Part 2) | 1,104 | Jan. 20, 2015, 3:56 p.m. |
| Alice's Birthday Party (Part 1) | 1,104 | Jan. 20, 2015, 3:55 p.m. |
| How do you become a big cryptographer? | 100 | Jan. 18, 2015, 8:45 p.m. |
| Cracking SHA1-Hashed Passwords | 1,108 | Jan. 18, 2015, 6:42 p.m. |
| Broadcasting and low exponent — RSA Attack | 1,110 | Jan. 16, 2015, 11:03 p.m. |
| RSA: Two different keys — same ciphertext | 1,111 | Jan. 14, 2015, 6:41 p.m. |
| BCR code (Book-Caesar-RSA) | 1,124 | Jan. 12, 2015, 9:41 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,105 | Jan. 10, 2015, 7:56 p.m. |
| Number Sequence | 100 | Jan. 8, 2015, 11:39 p.m. |
| Hill Cipher with Sudoku Key | 100 | Jan. 8, 2015, 5:01 p.m. |
| Snow White and the seven dwarfs | 100 | Jan. 5, 2015, 9:02 p.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Jan. 3, 2015, 9:21 p.m. |
| Factorization Cipher — Part 3 | 1,115 | Jan. 3, 2015, 8:45 p.m. |
| Factorization Cipher — Part 2 | 1,114 | Jan. 1, 2015, 7:17 p.m. |
| Modified Caesar Cipher | 100 | Dec. 31, 2014, 6:40 p.m. |
| Original Caesar Cipher | 100 | Dec. 31, 2014, 12:13 a.m. |
| Number Sequence — Part 2 | 100 | Dec. 30, 2014, 11:45 p.m. |
| One-Time Pad with Flaws | 100 | Dec. 30, 2014, 7:15 p.m. |
| Factorization Cipher — Part 1 | 100 | Dec. 30, 2014, 5:10 p.m. |
| Grille Cipher | 100 | Dec. 29, 2014, 3:39 p.m. |
| M-138 — Part 2 | 1,576 | Dec. 29, 2014, 3:36 a.m. |
| Beaver Code | 100 | Dec. 28, 2014, 8:53 p.m. |
| Letter to the Templars — Part 3 | 1,125 | Dec. 28, 2014, 2:48 p.m. |
| Letter to the Templars — Part 2 | 100 | Dec. 27, 2014, 11:08 p.m. |
| Letter to the Templars — Part 1 | 100 | Dec. 27, 2014, 10:21 p.m. |
| M-138 — Part 1 | 125 | Dec. 27, 2014, 8:22 p.m. |
| Pigpen with a twist — Part 1 | 100 | Dec. 27, 2014, 7:15 p.m. |
| Playfair with hints about the grid | 100 | Dec. 27, 2014, 2:38 p.m. |
| Playfair Encryption | 100 | Dec. 26, 2014, 6:50 p.m. |
| Caesar Encryption | 100 | Dec. 25, 2014, 5:31 p.m. |
Gold0
Silver0
Bronze3
