TextSecure is probably the best open source messaging app out there, and a worthy component to WhatsApp. I’m using the app for over a year now and I’m really happy with it. That’s why I decided to make a TextSecure feature overview, to give everyone, who is thinking about changing their messaging application, an idea how powerful TextSecure is and could be in the future.

Technical background

 Open Source TextSecure is, not as WhatsApp or Telegram, completely open source. This implies, that everyone is able to see every bit of code and everyone can suggest changes to this code. Within such a structure it is very unlikely, that somebody is able to add code that tracks people or is malicious. The openness of software is the first step to a truly private and secure software. Even if you can’t understand and check the code others have written, a lot of other people did that for you. If you want to help as well you can contribute to their code, translation or discuss ideas.

Encrypted TextSecure is encrypted with the Diffie-Hellman algorithm. The huge advantage of this algorithm is that

  • it exists since the 1970s and has never been cracked ever since.
  • it is possible to prove mathematically, that it takes huge amounts of computing power and hundreds of years to crack a single key
  • it is easy to compute the original message, if you know the shared secret
  • it is not possible for anyone else but the two messaging partner, to find out their shared secret, even though they establish it publicly

TextSecure decided to encrypt every message, so you only send plain text to non-TextSecure users. It is also possible to encrypt your whole message storage with a password, to make it impossible for anyone else to read your messages or send one in your name (identity).

SMS and internet TextSecure supports normal SMS as well as communication via the internet. It also can be used as a normal SMS client, which makes it useful for everyone. I, for example, have no other SMS app on my phone but this one. It’s cool to see all messages in one app, and to be able to encrypt the storage.


Group chat TextSecure supports group chat, which is as well encrypted. The chat can have a name and an image, like you would suspect. It has pretty much the same features as the group chat in WhatsApp.

Attachments TextSecure supports images videos and audio as attachments. This feature sometimes has a few errors, but all in all it works like it should. There is no possibility yet to record audio messages on the fly, but I’m also not sure if this will really be the next thing in the future.

Smileys TextSecure has tons of smileys. They are from google and have a great quality. No complains about them, there are way more than WhatsApp has, so if you like smileys, you will have no problems to express yourself with TextSecure. You find them either by switching to the special chracters keyboard (in the lower right corner), or by long-pressing on the enter key (I think this only works for Android 4.0 and above). 🙂 😉 😛 😀

 What I would like to see

I think TextSecure still has three big problems. One of them is the user base. TextSecure has, even though it has excellent reviews, only 100.000 – 500.000 downloads on the Google Play store. This is not so bad, but messaging applications live from a big user base. Right now I just can’t say that I will give up WhatsApp completely, because only 10 of my contacts have TextSecure. Compared to that, almost everybody has WhatsApp. TextSecure is trying to expand via the CyanogenMod project, which is a great way to start. We will see, if they can create a critical mass with this strategy.

The second problem I see, is that it is still only available for Android, which makes it no overall solution for everyone. A version for iOS is in development and will be released this summer. A version for windows phone is not planed in the next time, which makes sense for the current size of the user base.

The third problem I see, are the small errors. TextSecure sometimes has problems with delivering messages, but the user gets no feedback, whether the message received its destination. Sometimes the attachments can’t be opened. Those small things sum up, and even though I think the quality of the app is amazing, it still needs a lot of polishing to reach the quality of a commercial messaging app.

Anyways, if you are an explorer of private-friendly environments, I strongly recommend to download this app. I’m really happy to see developments like this, hopefully we won’t give up on freedom, privacy and security.

Download textSecure for andorid

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  1. I like the simplicity of the Textsecure app, but as a ‘lay’ user who has just got their first smartphone, I just can’t figure out how to add a contact. I have searched Google, and it is like they just don’t think someone needs to know something so basic. Well we do.

    1. Hey Abel,
      You probably didn’t find anything, because Textsecure normally does that automatically. If you set it up to sync your contacts (you did that, when you first started the App), Textsecure will look through your phone book and find contacts that use Textsecure. When you click on the plus sign in the top bar, you will find all your Textsecure contacts in a list. Below that list is the list of all your phone book contacts. If you are missing an entry, you can click on the refresh sign in the upper right corner.

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