GreHack CTF 2017
8 challenges with 9 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 CTFtimeCryptography2
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.
- dsa
- cryptography
Same technique in picoCTF: StegoRSA, Timestamped Secrets, AES-ABC
- cryptography
- rsa
Same technique in picoCTF: StegoRSA, john_pollard, rsa_oracle
Binary exploitation2
Turn a memory-safety bug in a native binary into control of execution. Usually a stack overflow, a format string, or a heap primitive.
- exploit
- overflow
- binary
Same technique in picoCTF: Guessing Game 1, x-sixty-what, PIE TIME 2
- exploit
Same technique in picoCTF: Guessing Game 1, x-sixty-what, format string 3
Steganography2
Find the payload hidden inside a carrier that looks ordinary. Bit planes, appended data, metadata, and audio spectrograms.
- steganography
Same technique in picoCTF: FindAndOpen, StegoRSA, Glory of the Garden
- steganography
Same technique in picoCTF: FindAndOpen, StegoRSA, Glory of the Garden
Web1
Reach data or functionality the application meant to keep from you - through its inputs, its tokens, or its trust in the client.
- web
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
Misc1
Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.
- hardware
Same technique in picoCTF: Permissions, Specialer, Codebook