I will show how to attack RSA, if two private keys share a same factor . This is the solution of an exercice - We had to decrypt a message given the ciphertext (encrypted message) and two public RSA keys (where a common factor was used to generate them).

There exists a nice command line interface for the quite famous WhatsApp Alternative named Telegram. Here is a short blog entry describing how to install and use it.

The Android Native Development Kit allows you to use C or C++ libraries in your Android Applications. I had to use it to build the official Android Telegram App, which uses this approach to include some libraries.

I had to decrypt a weak RSA encrypted message. Why weak? Because a (only) 268-bit key was used for encryption. So RSA is not bad, but please use a suitable key size.

GDB is a famous tool for binary instrumentation, reverse engineering and debugging. You will find some common commands and tips.

We had to do some basic nfs tag reading and writing (Short Records, Multiple Short Records). Here is some kind of an overview...

I had to use a USB CardReader (Omnikey 5421) in a course. This device will not work out of the box (at least not in Ubuntu 15.10 64-bit) so you will have to do some *magic* described in this post...

A step-by-step guide how to generate a call-graph for sendmail by using valgrind/callgrind.