Viber has provided the control of private conversation to its user. The team of viber has ensured the end to end encryption so that users can chat or talk freely without fear of losing privacy. By authenticating a contact on the app is that it protects the private data from hackers. Moreover, the hidden chat option provides more privacy. Its means no one can read your chats when someone is using your phone. By authenticating a contact your communication become completely secure and you can stay in touch without losing your personal information.
You can also do Secret Chat with any Contact number on Viber. In this way your Chat will be more secure.
Let's see how can you use this Feature
Open Viber Mobile App like this
Open Chat Box of Viber.
Open any contact whom you want to do secret chat.
Click on top right 3 dots to get further information details.
Click on the option "Secret Chat" like this
Now a new conversation thread will be open in chat box with a icon of "Lock" along with contact picture.
It indicates that you are having secret chat with this contact person.
Note: While doing secret chat you could not take screen shots of conversation due to privacy issues.