Wirebook › Glossary › End-to-end encryption
What is end-to-end encryption?
In one sentence: Locking a message on the sender's device so that only the receiver's device can unlock it, with nobody in between able to read it.
A little more
Normal web encryption protects a message on its way to the server, but the server itself can read it. End-to-end encryption locks the message on your device and only the receiver's device holds the key, so the company in the middle only ever carries scrambled data.
Many chat apps use it. Its strength depends on the keys staying on the two ends, which is why secret-note links often keep the key in the part of the URL after #, which is never sent to the server.
It's a bit like… Posting a locked box to a friend who has the only other key: the postal service can carry it but can't open it.