New Challenges
This page contains lists of recent and most difficult challenges. To play the challenges, please go to the challenges section.
Recently Released
| Category | Challenge | Points | Solves |
| CTF Archive | Unimplemented | 0 | 2 solves |
| CTF Archive | Unevaluated | 0 | 1 solves |
| CTF Archive | Calm Down | 0 | 0 solves |
| CTF Archive | 2020 | 0 | 6 solves |
| CTF Archive | Key recovery | 0 | 1 solves |
| CTF Archive | Unbalanced | 0 | 1 solves |
| CTF Archive | Probability | 0 | 1 solves |
| CTF Archive | ed25519 magic | 0 | 3 solves |
| CTF Archive | Sign in Please | 0 | 0 solves |
| CTF Archive | Functional | 0 | 1 solves |
| CTF Archive | SpongeBob SquarePants / Battle for Bikini Bottom - Rehydrated | 0 | 3 solves |
| Mathematics | No Way Back Home | 100 | 153 solves |
| Symmetric Ciphers | Beatboxer | 150 | 70 solves |
| Hash Functions | MDFlag | 125 | 75 solves |
| Crypto on the Web | TLS Handshake | 15 | 192 solves |
| Crypto on the Web | Saying Hello | 20 | 189 solves |
| Crypto on the Web | Secure Protocols | 5 | 224 solves |
| Crypto on the Web | Sharks on the Wire | 10 | 205 solves |
| Elliptic Curves | Real Curve Crypto | 200 | 45 solves |
| Crypto on the Web | RSA or HMAC? Part 2 | 100 | 326 solves |
| Mathematics | Roll your Own | 125 | 188 solves |
| Symmetric Ciphers | Dancing Queen | 120 | 218 solves |
| General | SSH Keys | 35 | 1695 solves |
| Misc | LFSR Destroyer | 250 | 63 solves |
| Hash Functions | Hash Stuffing | 50 | 332 solves |
| Elliptic Curves | Montgomery's Ladder | 40 | 347 solves |
| Elliptic Curves | Double and Broken | 50 | 183 solves |
| Diffie-Hellman | The Matrix Revolutions | 125 | 126 solves |
| Diffie-Hellman | The Matrix Reloaded | 100 | 197 solves |
| Diffie-Hellman | The Matrix | 75 | 268 solves |
| Crypto on the Web | JSON in JSON | 40 | 924 solves |
| Symmetric Ciphers | Oh SNAP | 120 | 216 solves |
| Misc | L-Win | 120 | 180 solves |
| Misc | Bruce Schneier's Password: Part 2 | 250 | 87 solves |
| Misc | Bruce Schneier's Password | 100 | 240 solves |
| Hash Functions | Mixed Up | 120 | 216 solves |
| Crypto on the Web | RSA or HMAC? | 35 | 1015 solves |
| Crypto on the Web | JWT Secrets | 25 | 1341 solves |
| Crypto on the Web | No Way JOSE | 20 | 1481 solves |
| Hash Functions | Jack's Birthday Hash | 20 | 1019 solves |
| Hash Functions | Jack's Birthday Confusion | 30 | 942 solves |
| Crypto on the Web | Token Appreciation | 5 | 2275 solves |
| Crypto on the Web | JWT Sessions | 10 | 1836 solves |
| Mathematics | Cofactor Cofantasy | 150 | 263 solves |
| Symmetric Ciphers | Logon Zero | 80 | 441 solves |
| RSA | RSA Backdoor Viability | 175 | 504 solves |
| Misc | Jeff's LFSR | 150 | 149 solves |
| General | Transparency | 50 | 2365 solves |
| RSA | Let's Decrypt Again | 175 | 175 solves |
| Hash Functions | Twin Keys | 100 | 193 solves |
Least Solved
| Category | Challenge | Points | Solves |
| CTF Archive | Calm Down | 0 | 0 solves |
| CTF Archive | Sign in Please | 0 | 0 solves |
| CTF Archive | Probability | 0 | 1 solves |
| CTF Archive | Functional | 0 | 1 solves |
| CTF Archive | Unbalanced | 0 | 1 solves |
| CTF Archive | Unevaluated | 0 | 1 solves |
| CTF Archive | Key recovery | 0 | 1 solves |
| CTF Archive | Unimplemented | 0 | 2 solves |
| CTF Archive | SpongeBob SquarePants / Battle for Bikini Bottom - Rehydrated | 0 | 3 solves |
| CTF Archive | ed25519 magic | 0 | 3 solves |
| CTF Archive | 2020 | 0 | 6 solves |
| Elliptic Curves | Real Curve Crypto | 200 | 45 solves |
| Misc | LFSR Destroyer | 250 | 63 solves |
| Symmetric Ciphers | Beatboxer | 150 | 70 solves |
| Hash Functions | MDFlag | 125 | 75 solves |
| Misc | Bruce Schneier's Password: Part 2 | 250 | 87 solves |
| Hash Functions | Invariant | 250 | 110 solves |
| Diffie-Hellman | The Matrix Revolutions | 125 | 126 solves |
| Misc | Trust Games | 150 | 146 solves |
| Misc | Jeff's LFSR | 150 | 149 solves |
| Mathematics | No Way Back Home | 100 | 153 solves |
| RSA | Let's Decrypt Again | 175 | 175 solves |
| Misc | L-Win | 120 | 180 solves |
| Elliptic Curves | Double and Broken | 50 | 183 solves |
| Mathematics | Roll your Own | 125 | 188 solves |