These are some challenges I made for CTF competitions organized by hxp.
The numbers are a very rough difficulty estimate on a scale from 0 to 9.
hxp CTF 2017
- (9) categorical: find collisions for the CGL supersingular isogeny hash function. files writeup
- (7) notsosmart: crack RSA keys generated using a bad key generation algorithm. files solution
- (6) 4ES: break 4-round AES. files solution
- (3) flea: crack an RSA key given some leakage depending on the factors. files solution
- (2) ouchenticated: break a homebrew CRC-based message authentication code. files solution
- (6) c_with_templates: embed printable shellcode into a constant string at compile time. files
- (5) lambda0xe: reverse-engineer obfuscated C++14 code. files
TUMCTF Teaser 2015
- (6) linear: linear cryptanalysis of a toy block cipher. files
- (2) really_slow_arithmetic: optimize an RSA private key. writeup