Letter Sealing is a feature that provides End-to-end encryption (E2EE) for chat room messages. E2EE is a communication system designed so that messages saved on our servers are encrypted and cannot be read by anyone except the sender and receiver of the message.

Once the sender and receiver have both turned on Letter Sealing, they will be able to start sending messages, but with added security.

If you use the PC version of LINE after turning on Letter Sealing, you will be required to verify your identity the first time you send a message.

To verify your identity, please refer to the Help article below.

To use Letter Sealing, please update LINE to version 5.3.0 or later via the link below.

When verifying your identity on the PC version of LINE, if the screen to enter the verification code for Letter Sealing does not appear on the smartphone version of LINE, please try the following:

1. Start the smartphone version of LINE.

2. Go to More > Settings > Privacy.

3. Turn Letter Sealing OFF, then turn it back ON again.

Afterwards, please refer to the following Help article and try verifying your identity once again.