Facebook calls are encrypted

End-to-end encryption for smartphone messengers

End-to-end encryption for smartphone messengers
Image: teltarif.de Encryption means that readable information (plain text) is converted into ciphertext using a key. The ciphertext can only be made readable again with the help of a matching key. With end-to-end encryption, data is encrypted at the sender before it is sent and only decrypted again at the recipient. The encryption and decryption takes place exclusively at the end points of the transmission. Even if a connection runs across several transmission stations, the information remains protected because no intermediate station has the necessary key to access the plain text of the message. A counterpart to end-to-end encryption is point-to-point encryption, in which all intermediate stations have access to the content of the sent messages. End-to-end encryption for smartphone messengers
Image: teltarif.de

The messenger service doesn't know what's in the news either

End-to-end encryption is intended to ensure that no one except the conversation partner can read what has been sent, not even the messenger service used itself. This works using an asymmetrical encryption method, also known as a public key system. In contrast to symmetrical systems, call participants do not have a shared secret key. Instead, each user generates a key pair consisting of a secret key (private key) and a non-secret key (public key). The sender can use the public key to encrypt messages, which the recipient can then decrypt again using his private key. Messages are therefore encoded with a public key, but can only be decoded again with a private key.

The public key works like a lock, for which only the recipient of the message has the appropriate key. Since no third party, not even the operator of the messenger service, has the private key, no one except the conversation partners can access the content of messages themselves. Companies that use end-to-end encryption therefore have no access to their customers' text messages and consequently cannot forward them to third parties. The same applies to other data such as images, videos or user locations. Voice calls can also be encrypted end-to-end.

Selected messengers that use end-to-end encryption

End-to-end messenger
Encryption (selection)
1 applies to voice and video calls only
2 only applies to secret chats and voice calls
One of the first popular messengers with end-to-end encryption was Apple's iMessage. Another is the smartphone messenger Threema, which, according to its own information, sends all messages exclusively end-to-end encrypted. The app even named itself after the process. “Threema” is derived from the acronym EEEMA, which stands for “End-to-End Encrypted Messaging Application”. Telegram Messenger and TextSecure's successor, Signal, also offer end-to-end encryption. The Signal Messenger provided the model for the later end-to-end encryption of WhatsApp. Both encryption methods come from the developer Open Whisper Systems. WhatsApp has been offering end-to-end encryption for some time
Photo: dpa

WhatsApp: data transfer despite encryption

WhatsApp has also been using end-to-end encryption since November 2014. The function is activated automatically and visualized by a corresponding message in the chat window. Nevertheless, the data of WhatsApp users does not remain completely anonymous. Since the chat client uses phone numbers to connect chat partners with one another, it accesses the user's phone book and can view all mobile phone numbers. The messaging app also stores traffic data. Even if the content of the messages is encrypted, WhatsApp can see who wrote whom and when.

Such data are anything but trivial because they allow significant conclusions to be drawn about the user's environment. And WhatsApp makes use of them. That is why the messaging service, which belongs to Facebook, came under fire from privacy advocates, as information was passed on to the parent company in order to use it for personalized advertising. The data passed on includes the phone numbers stored in the phone book. The Facebook Messenger also offers end-to-end encryption - albeit optional
Photo: dpa

Facebook Messenger is following suit with end-to-end encryption

In the meantime, users of the Facebook Messenger can also secure their chats with end-to-end encryption. Unlike WhatsApp, Threema and Co., the function in Messenger is not activated by default. End-to-end encryption only takes place if a secret conversation is deliberately selected in advance. This is because the Facebook Messenger can be used across platforms. A conversation that was started on one device can therefore be continued on another device. If end-to-end encryption were permanently active, this would no longer be possible, since secret conversations are only stored on one device and are automatically deleted after 24 hours at the latest. Furthermore, no GIFs or videos can be exchanged and no voice calls can be made in secret mode.

Messenger is therefore not a real alternative to completely encrypted services. However, if you are already in a Facebook conversation and would like to spontaneously exchange confidential data, you can now switch to secret mode at least temporarily.

Guide to messengers for smartphones, tablets and computers