As of November 2015, TextSecure is now named “Signal”. Signal integrates both RedPhone and encrypted text messaging in one app. Signal Private Messenger by Open Whisper Systems, is a messaging app that allows you to take back your privacy while easily communicating with friends. Using Signal, you can communicate instantly while avoiding SMS fees, create groups so that you can chat in real time with all your friends at once, and share media or attachments all with complete privacy. The server never has access to any of your communication and never stores any of your data.
- Signal uses an advanced end to end encryption protocol that provides privacy for every message every time.
- Encryption keys are exchanged between Signal users automatically and seamlessly.
- Signal is Free and Open Source, enabling anyone to verify its security by auditing the code.Signal is the only private messenger that uses open source peer-reviewed cryptographic protocols to keep your messages safe.
- Signal allows you to create encrypted groups so you can have private conversations with all your friends at once. Not only are the messages encrypted, but the Signal server never has access to any group metadata such as the membership list, group title, or group icon.
- The Signal protocol is designed to operate in the most constrained environment possible. Using Signal, messages are instantly delivered to friends.
- Also available for iPhone and desktop PC.
Signal functions just like your regular text messenger. In fact it can and should be your replacement for your insecure text messenger. Even if someone else does not have text secure you can still communicate normally except your communications will not be end to end encrypted. Here is a list of your prior text message conversations. Tapping the icon in the lower right corner will start a new conversation with someone not visible in the past conversation list.
Tapping the three dots in the upper right hand corner will open up the options.
When both parties use Signal you will see the padlock below the conversation text. This is to show you end to end encryption is in effect and your conversation is encrypted. When you initiate a conversation with someone that has Signal, behind the scenes Signal will exchange public keys with the other person without user intervention. The message you composed will then be encrypted using the recipients public key, sent encrypted over the air where it arrives on the recipients device, then decrypted and stored in their secure Signal container on their phone. All of this happens seamlessly. Encryption has never been so easy, even your grandmother mother can do it.
The conversation flow is just like your stock text messenger. It is neatly laid out and intuitive. Here you see an example conversation between two individuals: Ezra Pound and Eustice Mullins Jr.
Optionally you can tap on the padlock at the top of the screen to verify the integrity of the encryption with the other person. You will both have to verify a set of numbers and letters. I tried making a screen capture of it, even with root Signal has built in security which will deny any screen capturing of any screen within TextSecure. This is important in the event you get malware on your device which is trying to compromise your security.
I recommend Signal as your default texting app. I also recommend RedPhone as your choice for secure voice communications. There are a few apps out there which claim to encrypt your communications. Your first question should be is if those apps are open source or not. If not, you should be weary about trusting them. The security of your communications would then rest in your full and perhaps blind trust in the company. With open source, you have a community of developers and researchers which can view and audit the code of the software to assure it is doing what is suppose to do. Problems can be found and dealt with quicker.
You can also add groups for group chat. This is very easy to do. Here is an example of creating a group and adding individuals in your contact list to it.
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