CCTF 2020
9 challenges with 14 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 CTFtimeCryptography4
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.
- cryptography-rsa
- crypto
Same technique in picoCTF: StegoRSA, john_pollard, rsa_oracle
- crypto
- rsa
Same technique in picoCTF: StegoRSA, john_pollard, rsa_oracle
- crypto
- xor
Same technique in picoCTF: Custom encryption, triple-secure, XtraORdinary
- crypto
- 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.
- risc-v
- hardware
- pwn
Same technique in picoCTF: Guessing Game 1, x-sixty-what, format string 3
- risc-v
- hardware
- pwn
Same technique in picoCTF: Guessing Game 1, x-sixty-what, format string 3
Web1
Reach data or functionality the application meant to keep from you - through its inputs, its tokens, or its trust in the client.
- flask
- misc
- web
- polyglot
Same technique in picoCTF: Client-side-again, dont-use-client-side, Irish-Name-Repo 3
Reverse engineering1
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
- lisp
- rev
Same technique in picoCTF: WinAntiDbg0x100, WinAntiDbg0x200, WinAntiDbg0x300
Forensics1
Recover something from a file, a capture, or a disk image - often from a part of it the format says is unused.
- discrete-log
- crypto
- chinese-remainder
Same technique in picoCTF: FindAndOpen, c0rrupt, extensions