Imagine the messages you type and those which are received on the other end could be read by someone you don't know, or have not allowed them to. One solution could be to encrypt them and then transmit over a more secure channel, but the server that is transmitting these messages might be storing them unencrypted.
In order to make the messaging completely secure from the point of origin to the destination, FriendCaller has now introduced Public/Private Key encryption, where the Public Key will be used to encrypt a message and the Private Key will be used to decrypt a message. The Public/Private Key-Pair will be created on your local device. The private key will be held secretly there, while the public key will be published for others to send you encrypted messages. That way, the message can only be decrypted on your device, which holds the private key. Nobody else in the middle can read your message, not even the sender who has actually encrypted the message.
Look out for the encryption lock icon. Whenever it appears as locked, your communication is secure. An open lock icon means that the communication is not secure.
Tapping it will enable or disable secure messaging.
However, if the encryption lock icon is not available, this means that your chat partner has not enabled encryption on his device or has an old FriendCaller version that does not support encryption.
Of course, yes! In your group details, you have an option to enable encryption for your group. If this option has been set to a locked state, all members will receive messages encrypted between each other, and only group members will be able to read those messages.
The small lock icon next to your group members' profile pictures will let you know if the member is able to receive secure messages or not. In case they have an open lock icon, then whenever a secure message is sent within a secure messaging group, they will get a notification to update their FriendCaller version or to enable encryption for their account, once the encryption has been enabled by a previously unencrypted group member the owner of the group has to enter the group details view in order to activate this member to receive the encrypted messages. The member should show the closed lock then.