Android applications security — part 1, reverse engineering and token storage problems by Adrian Defus

There are many ways you can store keys and tokens in your Android applications — directly in the code, inside your database or by using NDK layer. But in terms of security — should you do it at all?

This article will show you the most common ways you can use to store different types of keys and tokens in your Android applications, while proving that none of these methods is good enough ????. The second part will contain more detailed considerations regarding how our application should communicate securely with the server, how to ensure the authentication of both entities, and how the attacker can affect our connection.

Looking inside our applications (reverse engineering)

The applications which we use on our devices are actually properly packed .apk files containing all the data required to operate correctly. If we want to view their content and see what is hidden there, we have to make some necessary preparations. First of all, we need a tool that will let us communicate with the mobile device using our computer — Android Debug Bridge is what we are looking for. Secondly if we want to disassemble our .apk files into separated source code files (.smali classes), Apktool seems to be the perfect....

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Hakin9 TEAM: Hakin9 is a monthly magazine dedicated to hacking and cybersecurity. In every edition, we try to focus on different approaches to show various techniques - defensive and offensive. This knowledge will help you understand how most popular attacks are performed and how to protect your data from them. Our tutorials, case studies and online courses will prepare you for the upcoming, potential threats in the cyber security world. We collaborate with many individuals and universities and public institutions, but also with companies such as Xento Systems, CATO Networks, EY, CIPHER Intelligence LAB, redBorder, TSG, and others.