Metro Manila Community Quarantine - Day 82
Facebook Messenger doesn't have end-to-end encryption enabled by default, but you have the option to create Secret Conversation that ensures encryption for that particular conversation. The Secret Chat option is only available on mobile devices running the Messenger app and is not visible on desktop version of Messenger whether standalone or integrated into Facebook. The caveat is that it's still a highly monetized Facebook platform.
WhatsApp, which is also a Facebook application, introduced end-to-end encryption for chats as default in recent years so no additional steps are needed to secure your chats there. Some argue its implementation is a little fishy, but it's still a bold promise and one that comes with cloud sync, so your messages are not constrained to their devices. It's only limited by how much you trust Facebook.
Viber also claims to have end-to-end encryption enabled as default starting with Viber ver 6.0. I don't use Viber enough to fully appreciate how true this is or not.
Telegram states that all messages on their platform are encrypted whereas their Secret Chats use client-side encryption on top of everything else. As far as messaging apps that are perceived to be more secure, this one is definitely one of the more popular ones with wider adoption. Secret Chats are only available for mobile devices but I've recently discovered the Unigram client for Windows that enables the Secret Chat experience for desktop.
Signal is another app that is highly respected for its security. Apart from end-to-end encryption by default, it throws in other security features including locking the app separately apart from your default screen lock, preventing screenshots, and preventing your keyboard from learning from your Signal text inputs. It's not the prettiest app and has relatively low user adoption outside specific circles but it delivers strongly on its security commitment.