2025weight 24.27Tower of Hanoi
ToH CTF 2025
2 challenges with 2 published community solutions between them. Solution links go to CTFtime’s task page, which aggregates every writeup for a challenge - individual blog posts rot, the aggregator does not.
Full task list on CTFtimeCryptography1
Recover a plaintext or a key from something that was supposed to protect it. In practice: identify the scheme, find the parameter the author got wrong, exploit it.
Solve it with:Cipher identifier and automatic decoderVigenere cipher solver with automatic key recoveryRSA decryption and attack runnerWiener’s attack on small RSA private exponentsIn-browser hash cracker with rule transformsLearn: Classical ciphers and frequency analysisLearn: RSA and the parameters that break it
- crypto
- rsa
Same technique in picoCTF: StegoRSA, john_pollard, rsa_oracle
Reverse engineering1
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
Solve it with:Strings extractor for binaries and blobsWebAssembly disassemblerJava .class disassemblerPython .pyc bytecode disassemblerLearn: Binary exploitation
- powerpc
- rev
Same technique in picoCTF: WinAntiDbg0x100, WinAntiDbg0x200, WinAntiDbg0x300