| Lightweight Introduction to Lattices — Part 2 | 100 | July 20, 2021, 7:33 p.m. |
| Strange Message from Thessaloniki | 100 | July 20, 2021, 7:26 p.m. |
| Recycled One-Time Pad | 100 | July 20, 2021, 12:49 a.m. |
| Find the right route — Part 3 | 100 | July 19, 2021, 11:33 p.m. |
| Find the right route — Part 2 | 100 | July 19, 2021, 10:52 p.m. |
| Find the right route — Part 1 | 100 | July 19, 2021, 10:32 p.m. |
| Wheatstone Cryptograph — Part 1 | 101 | July 19, 2021, 10:12 p.m. |
| Music Code — Part 2 | 1,082 | July 19, 2021, 9:32 p.m. |
| Music Code — Part 1 | 100 | July 19, 2021, 8:16 p.m. |
| Modular Sequences | 100 | July 19, 2021, 6:48 p.m. |
| Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 1,082 | July 19, 2021, 6:25 p.m. |
| The Einstein Enigma | 1,111 | July 18, 2021, 5:51 a.m. |
| Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 100 | July 18, 2021, 5:34 a.m. |
| Summer Job | 1,114 | July 18, 2021, 5:17 a.m. |
| Unusual encryption using a diophantine equation | 1,083 | July 18, 2021, 5:01 a.m. |
| Lightweight Introduction to Lattices — Part 3 | 1,157 | July 18, 2021, 4:26 a.m. |
| Lightweight Introduction to Lattices — Part 1 | 100 | July 17, 2021, 3:53 p.m. |
| Lattice Part 1 | 1,082 | July 16, 2021, 7:34 p.m. |
| M-138 — Part 2 | 1,093 | July 12, 2021, 9:47 p.m. |
| Fastest in the West | 1,114 | July 12, 2021, 8:39 p.m. |
| A hidden word — Part 2 | 100 | July 12, 2021, 8:03 p.m. |
| Enigma Combinatorics | 100 | July 12, 2021, 7:17 p.m. |
| Double Columnar Transposition | 100 | July 12, 2021, 7:02 p.m. |
| Hill Cipher with Sudoku Key | 100 | July 12, 2021, 6:13 p.m. |
| M-138 — Part 1 | 100 | July 12, 2021, 5:38 p.m. |
| Enigma Messages with Repeated Letters — Part 1 | 100 | July 12, 2021, 5:23 p.m. |
| A really long number sequence | 1,083 | July 11, 2021, 1:15 p.m. |
| BCR code (Book-Caesar-RSA) | 1,086 | July 10, 2021, 6:10 p.m. |
| RSA Factoring Challenge: RSA-250 | 0 | July 10, 2021, 4:54 p.m. |
| RSA Factoring Challenge: RSA-232 | 0 | July 10, 2021, 4:54 p.m. |
| Partial Key Exposure with RSA — Part 1 | 1,084 | July 10, 2021, 12:58 p.m. |
| Factorization Cipher — Part 2 | 1,084 | July 10, 2021, 12:40 p.m. |
| ¿No Hablas Español? No problemo! | 100 | July 9, 2021, 6:07 p.m. |
| Snow White and the seven dwarfs | 100 | July 9, 2021, 5:46 p.m. |
| The Last Note | 100 | July 9, 2021, 4:05 p.m. |
| Not-so-Secret Message from Malawi — Part I (RSA) | 1,081 | July 9, 2021, 3:06 p.m. |
| RSA Factoring Challenge: RSA-240 | 0 | March 2, 2020, 11 a.m. |
| Brute-Force-Attack on Triple-DES with Reduced Key Space | 1,084 | March 2, 2020, 10:56 a.m. |
| RSA Factoring Challenge: RSA-704 | 0 | March 2, 2020, 10:16 a.m. |
| RSA Factoring Challenge: RSA-220 | 0 | March 2, 2020, 10:16 a.m. |
| RSA Factoring Challenge: RSA-210 | 0 | March 2, 2020, 10:15 a.m. |
| RSA Factoring Challenge: RSA-230 | 0 | March 2, 2020, 10:14 a.m. |
| Keyshanc — Part 1 | 1,089 | Feb. 26, 2020, 12:18 p.m. |
| CMEA 1 | 1,085 | Feb. 25, 2020, 6:44 p.m. |
| Hybrid Encryption I | 1,084 | Feb. 22, 2020, 1:06 p.m. |
| Number Sequence — Part 10 | 100 | Feb. 21, 2020, 3:03 p.m. |
| ECDH-Key Exchange for Beginners | 100 | Feb. 21, 2020, 2:32 p.m. |
| The Book Code: A Challenge for Bookworms | 100 | Feb. 21, 2020, 2:10 p.m. |
| RSA: Two different keys — same ciphertext | 1,086 | Feb. 21, 2020, 1:59 p.m. |
| Image Noise | 100 | Feb. 21, 2020, 1:35 p.m. |
| Trifid Cipher | 100 | Feb. 21, 2020, 1:32 p.m. |
| Nils away on travel | 100 | Feb. 21, 2020, 12:04 p.m. |
| ADFGVX — Part 2 | 100 | Feb. 21, 2020, 11:49 a.m. |
| ADFGVX — Part 1 | 100 | Feb. 21, 2020, 11:41 a.m. |
| Alice's Birthday Party (Part 2) | 1,084 | Feb. 21, 2020, 11:30 a.m. |
| Broadcasting and low exponent — RSA Attack | 1,086 | Feb. 21, 2020, 11:25 a.m. |
| Letter from the Alleged Countess Julie von Ortenburg | 100 | Feb. 21, 2020, 11:09 a.m. |
| Molehunt (Part 3/3) | 1,084 | Feb. 5, 2020, 9:20 a.m. |
| Molehunt (Part 2/3) | 100 | Feb. 5, 2020, 8:48 a.m. |
| Molehunt (Part 1/3) | 100 | Feb. 5, 2020, 8:36 a.m. |
| Classical Ciphers^3 | 100 | Jan. 19, 2020, 12:13 p.m. |
| Pigpen with a twist — Part 1 | 100 | Jan. 8, 2020, 9:05 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 2 | 100 | Jan. 8, 2020, 8:30 p.m. |
| Number Sequence — Part 5 | 100 | Jan. 8, 2020, 8:20 p.m. |
| A modified homophonic cipher with reduced alphabets — Part 1 | 100 | Jan. 8, 2020, 8:15 p.m. |
| Number Sequence — Part 8 | 100 | Jan. 8, 2020, 8:10 p.m. |
| Number Sequence — Part 4 | 100 | Jan. 8, 2020, 8:09 p.m. |
| Autokey Cipher | 100 | Jan. 8, 2020, 6:47 p.m. |
| Alice's Birthday Party (Part 1) | 1,085 | Jan. 8, 2020, 12:50 p.m. |
| Cracking SHA1-Hashed Passwords | 1,086 | Jan. 8, 2020, 12:29 p.m. |
| One-Time Pad with Flaws | 100 | Jan. 8, 2020, 12:14 p.m. |
| Advent-Challenge — Part 1 | 100 | Jan. 8, 2020, 11:52 a.m. |
| Modified Caesar Cipher | 100 | Jan. 8, 2020, 11:47 a.m. |
| Factorization Cipher — Part 1 | 100 | Jan. 8, 2020, 11:11 a.m. |
| Monoalphabetic Substitution | 100 | Jan. 8, 2020, 11:07 a.m. |
| How do you become a big cryptographer? | 100 | Jan. 8, 2020, 10:47 a.m. |
| Grille Cipher | 100 | Jan. 8, 2020, 10:44 a.m. |
| From Russia with Love | 100 | Jan. 8, 2020, 10:34 a.m. |
| A hidden word | 100 | Jan. 8, 2020, 10:28 a.m. |
| Affine Codes / Modulo Arithmetic with N / Extended Euclid | 100 | Jan. 8, 2020, 9:57 a.m. |
| Letter to the Templars — Part 3 | 1,090 | Jan. 8, 2020, 9:54 a.m. |
| Letter to the Templars — Part 2 | 100 | Jan. 8, 2020, 9:49 a.m. |
| Letter to the Templars — Part 1 | 100 | Jan. 8, 2020, 9:47 a.m. |
| Beaver Code | 100 | Jan. 8, 2020, 9:24 a.m. |
| Caesar Encryption | 100 | Jan. 8, 2020, 9:15 a.m. |
| Number Sequence — Part 2 | 100 | Jan. 8, 2020, 9:12 a.m. |
| Original Caesar Cipher | 100 | Jan. 8, 2020, 9:09 a.m. |
| Number Sequence | 100 | Jan. 8, 2020, 8:50 a.m. |