| 1 | Classical Ciphers^3 | 203 |
| 1 | A Secret Message from Castle Mansfeld | 136 |
| 2 | Alice's Birthday Party (Part 1) | 347 |
| 2 | Alice's Birthday Party (Part 2) | 347 |
| X | D'Agapeyeff | 0 |
| X | Dorabella | 0 |
| X | Double Column Transposition | 2 |
| X | Kryptos | 0 |
| 1 | Letter from the Alleged Countess Julie von Ortenburg | 186 |
| 2 | Not-so-Secret Message from Malawi — Part I (RSA) | 221 |
| 2 | Not-so-Secret Message from Malawi — Part II (ECC) | 44 |
| X | Notes of an Italian Soldier | 4 |
| 3 | RSA with Special d | 25 |
| X | Beale Ciphers | 1 |
| X | Unknown Author | 2 |
| 1 | Number Sequence | 4892 |
| 1 | Monoalphabetic Substitution | 591 |
| X | Ku Klux Klan | 44 |
| 3 | World Record Challenge: Break 65 Bits of AES | 0 |
| 2 | ORYX Stream Cipher Part I | 82 |
| 2 | ORYX Stream Cipher Part II | 49 |
| 1 | Zodiac Cipher | 112 |
| 2 | Enigma Part 1 | 137 |
| 2 | Enigma Part 2 | 97 |
| 3 | Sigaba Part 2 | 5 |
| 2 | Brute-Force-Attack on Triple-DES with Reduced Key Space | 250 |
| 2 | Sigaba Part 1 | 18 |
| 1 | A modified homophonic cipher with reduced alphabets — Part 1 | 428 |
| 1 | A modified homophonic cipher with reduced alphabets — Part 2 | 371 |
| 1 | Caesar Encryption | 1650 |
| 1 | Molehunt (Part 1/3) | 171 |
| 1 | Molehunt (Part 2/3) | 161 |
| 2 | Molehunt (Part 3/3) | 90 |
| 2 | Smartcard RSA | 82 |
| 2 | Purple 1 | 22 |
| 2 | Hybrid Encryption I | 194 |
| 1 | One-Time Pad with Flaws | 335 |
| 1 | Enigma Combinatorics | 116 |
| 2 | Akelarre Part 1 | 11 |
| 2 | CMEA 1 | 47 |
| 3 | CMEA 2 | 30 |
| 1 | Original Caesar Cipher | 3517 |
| 1 | Playfair Encryption | 142 |
| 2 | Lunchtime Attack on the Fully Homomorphic Encryption Scheme | 49 |
| 3 | Recovering the Private Key in the Fully Homomorphic Encryption Scheme | 0 |
| 1 | Kaskade-S/T — Part 1 | 113 |
| 2 | Kaskade-S/T — Part 2 | 58 |
| 2 | Kaskade-S/T — Part 3 | 38 |
| 2 | Lattice Part 1 | 36 |
| 2 | Cracking SHA1-Hashed Passwords | 675 |
| X | Twelve-Year-Old Murder Case | 0 |
| 1 | Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 1 | 105 |
| 2 | Post-Quantum Cryptography: Unbalanced Oil and Vinegar System — Part 2 | 13 |
| 2 | Kaskade-S/T — Part 4 | 0 |
| 2 | Kaskade-S/T — Part 5 | 10 |
| 1 | Music Code — Part 1 | 45 |
| 2 | Music Code — Part 2 | 44 |
| 3 | Substitution Cipher with Non-Prefix Codes | 1 |
| 1 | Number Sequence — Part 2 | 2409 |
| 2 | Broadcasting and low exponent — RSA Attack | 264 |
| 2 | RSA: Two different keys — same ciphertext | 166 |
| 1 | ADFGVX — Part 1 | 134 |
| 1 | ADFGVX — Part 2 | 137 |
| 3 | Digital Signatures: DSA with Medium Fields | 0 |
| 2 | Unusual encryption using a diophantine equation | 70 |
| 1 | Modified Caesar Cipher | 262 |
| 1 | Pigpen with a twist — Part 1 | 167 |
| 2 | Pigpen with a twist — Part 2 | 48 |
| 2 | Pigpen with a twist — Part 3 | 47 |
| 2 | A really long number sequence | 128 |
| 1 | Affine Codes / Modulo Arithmetic with N / Extended Euclid | 661 |
| X | The third ENIGMA M4 message | 0 |
| 1 | Double Columnar Transposition | 128 |
| 1 | Grille Cipher | 549 |
| 1 | An Invisible Message | 72 |
| 1 | Turing Bombe Enigma I | 84 |
| 1 | Factorization Cipher — Part 1 | 560 |
| 1 | Monoalphabetic substitution with camouflage — Part 1 | 72 |
| 2 | Unconcealed RSA messages | 56 |
| 2 | Factorization Cipher — Part 2 | 159 |
| 2 | Monoalphabetic substitution with camouflage — Part 2 | 58 |
| 2 | Monoalphabetic substitution with camouflage — Part 3 | 54 |
| 1 | Monoalphabetic substitution with camouflage — Part 4 | 54 |
| 2 | Factorization Cipher — Part 3 | 101 |
| 2 | AES key — encoded in the machine readable zone of a European ePassport | 92 |
| 2 | RSA Factoring Challenge: RSA-210 | 64 |
| 2 | RSA Factoring Challenge: RSA-220 | 47 |
| 2 | RSA Factoring Challenge: RSA-230 | 40 |
| 3 | RSA Factoring Challenge: RSA-232 | 29 |
| 3 | RSA Factoring Challenge: RSA-240 | 29 |
| 3 | RSA Factoring Challenge: RSA-250 | 28 |
| 3 | RSA Factoring Challenge: RSA-260 | 0 |
| 3 | RSA Factoring Challenge: RSA-270 | 0 |
| 3 | RSA Factoring Challenge: RSA-896 | 0 |
| 3 | RSA Factoring Challenge: RSA-280 | 0 |
| 3 | RSA Factoring Challenge: RSA-290 | 0 |
| 3 | RSA Factoring Challenge: RSA-300 | 0 |
| 3 | RSA Factoring Challenge: RSA-309 | 0 |
| 3 | RSA Factoring Challenge: RSA-1024 | 0 |
| 3 | RSA Factoring Challenge: RSA-310 | 0 |
| 3 | RSA Factoring Challenge: RSA-320 | 0 |
| 3 | RSA Factoring Challenge: RSA-330 | 0 |
| 3 | RSA Factoring Challenge: RSA-340 | 0 |
| 3 | RSA Factoring Challenge: RSA-350 | 0 |
| 3 | RSA Factoring Challenge: RSA-360 | 0 |
| 3 | RSA Factoring Challenge: RSA-370 | 0 |
| 3 | RSA Factoring Challenge: RSA-380 | 0 |
| 3 | RSA Factoring Challenge: RSA-390 | 0 |
| 3 | RSA Factoring Challenge: RSA-400 | 0 |
| 3 | RSA Factoring Challenge: RSA-410 | 0 |
| 3 | RSA Factoring Challenge: RSA-420 | 0 |
| 3 | RSA Factoring Challenge: RSA-430 | 0 |
| 3 | RSA Factoring Challenge: RSA-440 | 0 |
| 3 | RSA Factoring Challenge: RSA-450 | 0 |
| 3 | RSA Factoring Challenge: RSA-460 | 0 |
| 3 | RSA Factoring Challenge: RSA-1536 | 0 |
| 3 | RSA Factoring Challenge: RSA-470 | 0 |
| 3 | RSA Factoring Challenge: RSA-480 | 0 |
| 3 | RSA Factoring Challenge: RSA-490 | 0 |
| 3 | RSA Factoring Challenge: RSA-500 | 0 |
| 3 | RSA Factoring Challenge: RSA-617 | 0 |
| 3 | RSA Factoring Challenge: RSA-2048 | 0 |
| 2 | Partial Key Exposure with RSA — Part 1 | 113 |
| 1 | ECDH-Key Exchange for Beginners | 110 |
| 2 | Monoalphabetic Substitution with Camouflage — Part 5 | 36 |
| 1 | The Book Code: A Challenge for Bookworms | 166 |
| 1 | Number Sequence — Part 3 | 1166 |
| 1 | ¿No Hablas Español? No problemo! | 190 |
| 1 | Number Sequence — Part 4 | 958 |
| 1 | Number Sequence — Part 5 | 127 |
| X | Concealed Messages — Vigenère's Night Sky | 16 |
| 2 | Keyshanc — Part 1 | 52 |
| 2 | Keyshanc — Part 2 | 43 |
| 1 | How do you become a big cryptographer? | 254 |
| 1 | An 'unhearable' message | 46 |
| 2 | Monoalphabetic Substitution with Camouflage — Part 6 | 2 |
| 1 | Letter to the Templars — Part 1 | 1150 |
| 1 | Letter to the Templars — Part 2 | 921 |
| 1 | Beaver Code | 1376 |
| 2 | BCR code (Book-Caesar-RSA) | 81 |
| 2 | Letter to the Templars — Part 3 | 769 |
| 1 | Recycled One-Time Pad | 79 |
| 1 | Strange Message from Thessaloniki | 53 |
| 1 | A hidden word | 983 |
| 1 | Playfair with hints about the grid | 133 |
| 1 | Enigma Messages | 94 |
| 1 | Cascading Encryption — Part 1/3 | 83 |
| 1 | Multilingual Monoalphabetic Substitution | 88 |
| 2 | Typex — Part 1 | 31 |
| 1 | Reserve Hand Procedure — Part 1 | 208 |
| 2 | Cascading Encryption — Part 2/3 | 25 |
| 2 | Cascading Encryption — Part 3/3 | 16 |
| 2 | Typex — Part 2 | 25 |
| 1 | Snow White and the seven dwarfs | 322 |
| 2 | ORYX Stream Cipher — Part 3 (revised) | 31 |
| 3 | ORYX Stream Cipher — Part 4d | 0 |
| 2 | RSA Factoring Challenge: RSA-704 | 69 |
| 1 | Nils away on travel | 195 |
| 1 | Hill Cipher with Sudoku Key | 122 |
| 1 | From Russia with Love | 327 |
| 1 | Enigma Messages with Repeated Letters — Part 1 | 201 |
| 1 | Trifid Cipher | 142 |
| 1 | Enigma Messages with Repeated Letters — Part 2 | 100 |
| 3 | Double Column Transposition Reloaded — Part 1 | 0 |
| 3 | Double Column Transposition Reloaded — Part 2 | 0 |
| 3 | Double Column Transposition Reloaded — Part 3 | 0 |
| 1 | Enigma Messages with Repeated Letters — Part 3 | 100 |
| 1 | Enigma Messages with Repeated Letters — Part 4 | 91 |
| 1 | Enigma Messages with Repeated Letters — Part 5 | 93 |
| 2 | Spanish Strip Cipher — Part 1 | 37 |
| 2 | Spanish Strip Cipher — Part 2 | 34 |
| X | Spanish Strip Cipher — Part 3 | 0 |
| 2 | Double Column Transposition — Part 1 | 35 |
| 2 | ORYX Stream Cipher — Part 4a | 12 |
| 3 | ORYX Stream Cipher — Part 4b | 2 |
| 3 | ORYX Stream Cipher — Part 4c | 0 |
| 2 | Double Column Transposition — Part 3 | 42 |
| 2 | Double Column Transposition — Part 2 | 49 |
| 2 | Double Column Transposition — Part 4 | 56 |
| 2 | Double Column Transposition — Part 5 | 11 |
| 1 | M-138 — Part 1 | 247 |
| 1 | Heartbleed — Part 1 | 90 |
| 1 | Heartbleed — Part 2 | 60 |
| 2 | Heartbleed — Part 3 | 33 |
| 2 | M-138 — Part 2 | 149 |
| 2 | M-138 — Part 3 | 70 |
| 1 | The Last Note | 115 |
| 2 | M-138 — Part 4 | 34 |
| 2 | Handycipher — Part 1 | 7 |
| 2 | Handycipher — Part 2 | 9 |
| 3 | Handycipher — Part 3 | 8 |
| 1 | Number Sequence — Part 6 | 195 |
| 1 | Number Sequence — Part 7 | 110 |
| 2 | Extended Handycipher — Part 1 | 4 |
| 2 | Extended Handycipher — Part 2 | 4 |
| 2 | Extended Handycipher — Part 3 | 4 |
| 1 | A hidden word — Part 2 | 136 |
| 2 | Weakened Handycipher — Part 1 | 18 |
| 2 | Weakened Handycipher — Part 2 | 16 |
| 2 | Weakened Handycipher — Part 3 | 16 |
| 2 | Double-Column Transposition/Granit — Part 1 | 0 |
| 2 | Double-Column Transposition/Granit — Part 2 | 0 |
| 2 | Double-Column Transposition/Granit — Part 3 | 0 |
| 2 | Flawed Usage of a OTP Cipher by the BND | 20 |
| 2 | Spirale — Part 1 | 8 |
| 2 | Spirale — Part 2 | 8 |
| 2 | Spirale — Part 3 | 6 |
| 3 | Spirale — Part 4 | 0 |
| 1 | Number Sequence — Part 8 | 473 |
| 1 | Weakened Granit — Part 1 | 53 |
| 2 | Weakened Granit — Part 2 | 0 |
| 2 | Weakened Granit — Part 3 | 0 |
| 1 | News from Castle Mansfeld | 63 |
| 1 | Image Noise | 200 |
| 1 | New Year's Greetings — Part 1 | 62 |
| 1 | New Year's Greetings — Part 2 | 55 |
| 1 | New Year's Greetings — Part 3 | 52 |
| 1 | New Year's Greetings — Part 4 | 50 |
| 2 | New Year's Greetings — Part 5 | 17 |
| 3 | Handycipher — Part 4 | 5 |
| 3 | Handycipher — Part 5 | 6 |
| 3 | Handycipher — Part 6 | 6 |
| 3 | Extended Handycipher — Part 4 | 4 |
| 3 | Extended Handycipher — Part 5 | 4 |
| 3 | Extended Handycipher — Part 6 | 3 |
| 2 | Weakened Handycipher — Part 4 | 7 |
| 2 | Weakened Handycipher — Part 5 | 7 |
| 2 | Weakened Handycipher — Part 6 | 7 |
| 2 | ASAC — A Strong(er) ADFGVX Cipher — Part 1 | 21 |
| 2 | ASAC — A Strong(er) ADFGVX Cipher — Part 2 | 1 |
| 2 | ASAC — A Strong(er) ADFGVX Cipher — Part 3 | 0 |
| 2 | ASAC — A Strong(er) ADFGVX Cipher — Part 4 | 0 |
| 2 | ASAC — A Strong(er) ADFGVX Cipher — Part 5 | 0 |
| 3 | Handycipher — Part 7 | 2 |
| 3 | Handycipher — Part 8 | 3 |
| 3 | Handycipher — Part 9 | 3 |
| 2 | Hilly — Part 1 | 9 |
| 2 | Holographic Encryption — Part 1 | 8 |
| 2 | Holographic Encryption — Part 2 | 3 |
| 2 | Kaskade-S/T — Part 6 (RansomKaskade Part 1) | 6 |
| 3 | ElsieFour — Part 1 | 4 |
| 2 | Weakened ElsieFour — Part 3 | 4 |
| 2 | Hilly — Part 2 | 1 |
| 1 | Number Sequence — Part 9 | 149 |
| 1 | Advent-Challenge — Part 1 | 611 |
| 2 | Advent-Challenge — Part 2 | 65 |
| 2 | AES ECB Wrong Encoding | 29 |
| 2 | Advent Challenge — Part 3 | 55 |
| 2 | Advent Challenge — Part 4 | 51 |
| 2 | The Einstein Enigma | 68 |
| X | The Vatican Challenge — Part 1 | 3 |
| X | The Vatican Challenge — Part 2 | 3 |
| 1 | Number Sequence — Part 10 | 145 |
| 2 | Weakened ElsieFour — Part 1 | 6 |
| 2 | Weakened ElsieFour — Part 2 | 1 |
| 2 | Summer Job | 68 |
| 2 | Fastest in the West | 42 |
| 2 | Trendy Messenger | 39 |
| 1 | Modular Sequences | 106 |
| 1 | Autokey Cipher | 239 |
| 2 | Breaking a Filter Generator | 24 |
| 1 | Cryptanalysis Hacking Puzzles — Part 1 | 40 |
| X | Catherine of Aragon's Letter to King Ferdinand, her Father (1509) | 2 |
| 2 | "The Road" — Part 1 | 9 |
| 2 | "The Road" — Part 2 | 2 |
| 2 | "The Road" — Part 3 | 0 |
| 1 | Cryptanalysis Hacking Puzzles — Part 2 | 260 |
| 2 | Monoalphabetic Substitution with Nostradamus Flavor | 45 |
| 2 | Handycipher made in love — Part 1 | 31 |
| 2 | Homophonic Encryption — Part 1 | 53 |
| 2 | Homophonic Encryption — Part 2 | 48 |
| 2 | Homophonic Encryption — Part 3 | 46 |
| 2 | Homophonic Encryption — Part 4 | 45 |
| 2 | Handycipher made in love — Part 2 | 25 |
| 2 | Handycipher — Part 10 | 1 |
| X | The Vatican Challenge — Part 3 | 0 |
| X | The Vatican Challenge — Part 4 | 1 |
| X | The Vatican Challenge — Part 5 | 0 |
| 2 | The T52 Sturgeon Challenge — Part 1 | 21 |
| 2 | The T52 Sturgeon Challenge — Part 2 | 20 |
| 2 | The T52 Sturgeon Challenge — Part 3 | 16 |
| 2 | The T52 Sturgeon Challenge — Part 4 | 14 |
| 2 | The T52 Sturgeon Challenge — Part 8 | 11 |
| 2 | The T52 Sturgeon Challenge — Part 9 | 9 |
| 2 | The T52 Sturgeon Challenge — Part 10 | 9 |
| 2 | The T52 Sturgeon Challenge — Part 11 | 10 |
| 2 | The T52 Sturgeon Challenge — Part 12 | 10 |
| 2 | The T52 Sturgeon Challenge — Part 5 | 8 |
| 2 | The T52 Sturgeon Challenge — Part 6 | 8 |
| 2 | The T52 Sturgeon Challenge — Part 7 | 8 |
| 2 | A Cloaked Substitution Cipher — Part 1 | 24 |
| 2 | A Cloaked Substitution Cipher — Part 2 | 23 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 1 | 2 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 2 | 3 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 3 | 3 |
| 2 | Cipher ID — Part 1 | 19 |
| 2 | Polyphonic Substitution Cipher — Part 1 | 27 |
| 2 | Christmas Challenge 2019: Differential Cryptanalysis — Part 1 | 5 |
| 2 | Polyphonic Substitution Cipher — Part 2 | 25 |
| 2 | Differential Cryptanalysis — Part 2 | 5 |
| 2 | The LoRa Cipher: Logic Randomness — Part 1 | 30 |
| 2 | The SIGABA Challenge — Part 1 | 12 |
| 2 | The SIGABA Challenge — Part 2 | 10 |
| 3 | The SIGABA Challenge — Part 3 | 6 |
| 3 | The SIGABA Challenge — Part 4 | 5 |
| 1 | Polyhomophonic Substitution — Part 1 | 64 |
| 3 | The SIGABA Challenge — Part 5 | 2 |
| 2 | Polyhomophonic Substitution — Part 2 | 35 |
| 3 | The SIGABA Challenge — Part 6 | 1 |
| 2 | Polyhomophonic Substitution — Part 3 | 21 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 4 | 6 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 5 | 7 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 6 | 5 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 7 | 8 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 8 | 0 |
| 3 | The Heavy T52 Sturgeon Challenge — Part 9 | 3 |
| 1 | Lightweight Introduction to Lattices — Part 1 | 69 |
| 1 | Lightweight Introduction to Lattices — Part 2 | 50 |
| 2 | Lightweight Introduction to Lattices — Part 3 | 41 |
| 2 | The SZ42 Challenge — Part 1 | 20 |
| 2 | The SZ42 Challenge — Part 2 | 20 |
| 2 | The SZ42 Challenge — Part 3 | 17 |
| 2 | The SZ42 Challenge — Part 4 | 18 |
| 2 | The SZ42 Challenge — Part 5 | 17 |
| 2 | The SZ42 Challenge — Part 6 | 15 |
| 2 | The SZ42 Challenge — Part 7 | 14 |
| 1 | Find the right route — Part 1 | 117 |
| 2 | The SZ42 Challenge — Part 8 | 15 |
| 2 | The SZ42 Challenge — Part 9 | 14 |
| 1 | Find the right route — Part 2 | 47 |
| 1 | Find the right route — Part 3 | 46 |
| 2 | The SZ42 Challenge — Part 10 | 7 |
| 2 | The SZ42 Challenge — Part 11 | 4 |
| 1 | Wheatstone Cryptograph — Part 1 | 133 |
| 2 | Wheatstone Cryptograph — Part 2 | 19 |
| 2 | SIGABA CSP-889 — Part 1 | 2 |
| 2 | SIGABA CSP-889 — Part 2 | 2 |
| 3 | SIGABA CSP-889 — Part 3 | 2 |
| 2 | SIGABA CSP-2900 — Part 1 | 2 |
| 2 | SIGABA CSP-2900 — Part 2 | 2 |
| 3 | SIGABA CSP-2900 — Part 3 | 2 |
| 2 | The SZ42 Challenge — Part 12 | 11 |
| 2 | The SZ42 Challenge — Part 13 | 10 |
| 2 | Modified Vigenère Cipher | 14 |
| 1 | Alberti Challenge — Part 1 | 188 |
| 2 | Alberti Challenge — Part 2 | 12 |
| 2 | Hill Cipher | 15 |
| 1 | Merkle-Hellman Knapsack Challenge - Part 1 | 100 |
| 2 | Merkle-Hellman Knapsack Challenge — Part 2 | 18 |
| 1 | The Syllabary Cipher – Part 1 | 345 |
| 2 | The Syllabary Cipher – Part 2 | 35 |
| 2 | The Syllabary Cipher – Part 3 | 24 |
| 2 | The Syllabary Cipher – Part 4 | 15 |
| 2 | The Syllabary Cipher – Part 5 | 15 |
| 3 | A Heavy SZ42 Challenge – Part 14 | 0 |
| 2 | The Josse Challenge – Part 1 | 17 |
| 2 | The Josse Challenge – Part 2 | 17 |
| 2 | The Josse Challenge – Part 3 | 14 |
| 2 | The Hutton Cipher – Part 1 | 26 |
| 2 | The Hutton Cipher – Part 2 | 28 |
| 2 | The Hutton Cipher – Part 3 | 4 |
| 2 | The Hutton Cipher – Part 4 | 4 |
| 2 | The Hutton Cipher – Part 5 | 0 |
| 1 | A disguised code | 90 |
| 2 | Elliptic Boogaloo – Part 1 | 4 |
| 3 | Elliptic Boogaloo – Part 2 | 3 |
| 3 | Elliptic Boogaloo – Part 3 | 3 |
| 2 | PX-1000 Encryption – Part 1 | 11 |
| 2 | The Fialka Challenge – Part 1 | 7 |
| 2 | The Fialka Challenge – Part 2 | 6 |
| 2 | The Fialka Challenge – Part 3 | 6 |
| 2 | The Lady Liz Challenge | 0 |
| 3 | Vinaigrette Signature Scheme | 3 |
| 1 | Bigram Substitution – Part 1 (Tutorial) | 56 |
| 2 | Bigram Substitution – Part 2 | 7 |
| 2 | Twisting the Rubik's Cube (Xmas Challenge) | 3 |