On 31 August 2016, a lock icon (lock indicator icon) was introduced on LINE chat room.
The lock indicator icon, however, does not always appear on chat room.
It appears or does not appear depending on the recipient.
Why does it happen?
By the way, what the lock indicator icon mean?
In this article, I will sum up the information about the lock indicator icon.
What does a lock indicator icon on LINE chat room mean?
A lock indicator icon is a function called “Letter Sealing” that provides end-to-end encryption (E2EE) for chat room messages and calls.
It ensures that messages for both the sender and recipient side cannot be read as they pass through LINE’s servers.
“Letter Sealing” had been available before its new release on August 2016, but it was optional.
Both of the sender and recipient had required to turn “Letter Sealing” on for its activation.
On August 2016, however, LINE Corporation significantly changed the specifications for the function.
“Letter Sealing” is enabled by default in supported versions of LINE, displaying a lock indicator icon on each chat room ensuring that no one other than the sender and recipient can read their chats.
I will explain the details of “Letter Sealing” in the following link.
Understanding how to secure your LINE chat will lead to benefits not only for yourself but also for your family and friends.
Reasons for the presence or absence of a lock indicator icon depending on the recipient
What do you think is the reason for the presence or absence of a lock indicator icon?
Some of you have already solved by the above-mentioned explanation.
A lock indicator icon will only be displayed on chat room where all the members on the chat room have also enabled “Letter Sealing”.
With the icon not being displayed on the chat room, the chat room will not be protected with end-to-end encryption.
A lock indicator icon is being displayed since both of the sender and recipient have enabled “Letter Sealing”
By the way, there are some cases where “Letter Sealing” does not apply even though all the members of the chat room turned the function on.
“Letter Sealing” will not be activated when the group chats members are over 50.
It is because currently “Letter Sealing” only supports group chats of up to 50 users (September 2016).
In terms of LINE free calls, “Letter Sealing” only includes 1-on-1 calls.
How to put a lock indicator icon on your chat room
You need to turn “Letter Sealing” on to put a lock indicator icon on your chat room.
Tick “Letter Sealing” from “More”> “Settings”> “Chats & Voice Calls”.
The recipients also need to turn “Letter Sealing” on for its activation.
I recommend that you lock your chat room all the time just like you lock your house.
It is possible to delete the lock indicator icon from your chat room (meaning deactivate “Letter Sealing”), but actually there are no merits for the deactivation.
Except special occasion, you should keep “Letter Sealing” turned on.