How to active end-to-end encryption on Facebook Messenger
An end-to-end encrypted conversation ensures that the information you send and receive is secure
Your calls and messages in a conversation are further secured and protected with end-to-end encryption so that only you and the other person can see, hear, or read them.
An end-to-end encrypted conversation is protected by a unique key that is stored on each device participating in the conversation.
1- Open the Facebook Messenger app on your smartphone.
2- Select the Chats option from the bottom menu.
3- Tap on the pen-like Edit icon available in the upper right corner of your screen.
4- Turn the toggle on for the lock icon in the top right
5- Then, select the name of the person you want to chat with.