Bad Primes 86 solves Easy Category: Crypto Author: midao Description : “I thought I understood the RSA primitive but apparently I generated the primitive’s primes too primitively… " 193 points Understanding the issue The challenge comes with Python code which implements RSA encryption/decryption. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 #!

Callboy 207 solves Baby Category: Misc Author: p4ck3to Description : “Have you ever called a Callboy? No!? Then you should definitely try it. To make it a pleasant experience for you, we have recorded a call with our Callboy to help you get started, so that there is no embarrassing silence between you. PS: do not forget the to wrap flag{} around the secret " 127 points An overview of network packets The file we download is a network packet capture.

Flagdroid 147 solves 153 points Easy Category: Reverse Author: m0ney Text: “This app won’t let me in without a secret message. Can you do me a favor and find out what it is?” Download file: an APK Analysis of the app We decompile the application. The validation of the flag is done when you press the button check: 1 2 3 4 5 6 7 8 9 10 11 12 13 public void onClick(View arg10) { TextView tvWrong = (TextView)MainActivity.