According to the changelog, it seems that Viber wants its users to know that its messages are encrypted and will display a small icon to show that it is. “Increased security – the padlock icon confirms that all your messages – including groups and cross platform messages – are end-to-end encrypted.”
In addition to encrypting chats, Viber is also allowing users to hide their chats. This isn’t so much users deleting or archiving their chats, but actually hiding to so that it looks like those chats were never there. There is also contact authentication that will hopefully prevent users from adding people they don’t know, which could help reduce phishing scams.
Given the fuss about the importance of privacy and security these days, if you are an avid Viber user then perhaps you’ll want to update ASAP. The update applies to both its iOS and Android versions, so if you haven’t downloaded the latest version of Viber yet, head on over to the iTunes App Store or Google Play for the download.