BSides SF CTF 2017 – Flag Receiver - Mobile Reverse Engineering

The second mobile reversing challenge of BSides SF CTF. Slightly harder than the first but only just. Here’s the clue and APK:

BSides SF CTF 2017 - []root - Crypto Challenge

Quick challenge for a quick 250 points. So hopefully a quick writeup! Here’s the clue:

HackIM - Breaking Bad Key Exchange - Crypto Challenge

HackIM time again. This year seemed slightly better organized than last year. Some nice challenges. I don’t think this challenge was worth 350 points but I’ll document my solution anyway in sort of a “what not to do” when making a crypto challenge. Here’s the clue including the image they gave as a description:

Sharif CTF 2016 - LSB Oracle - Crypto Challenge

Cool challenge that I’ve wanted a reason to solve for a while because I always miss these in CTFs of the past (Tokyo Westerners CTF had a good, harder one previously).

SECCON 2016 Quals - Memory Analysis - Forensics Challenge

Very unimaginativly entitled challenge with a lot of hints should have been pretty straightforward. And yeah it was pretty much so a very quick writeup this time. The clue was: