Warning: Telegram is not end-to-end encrypted by default

After tech behemoths like Twitter moved to ban Trump and thousands of other far-right accounts, millions moved to apps like Signal and Telegram for their encrypted messaging services.

There's one rub, though: Telegram, unlike Signal, doesn't have end-to-end encryption by default.

End-to-end encryption means that only the message sender and receiver can read the message. Even the server that hosts it, such as Signal or iMessage on Apple devices, can't decrypt and read what someone wrote. If those servers were ever hacked, hackers wouldn't be able to read the messages, either. It's safe to say, then, that end-to-end (e2e) encryption is an imperative element to secure messaging.

As New York Times tech reporter Mike Isaac pointed out on Twitter, those conflating Signal and Telegram are doing so wrongfully because of this difference:

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"Signal is [pretty] much a classic 'messenger' product, end-to-end encrypted by default," Isaac explained. "Telegram acts more like a social network+messenger and is NOT e2e by default."

Indeed, according to its FAQ, a user has to make a Telegram chat "secret" in order for it to be e2e encrypted. Telegram has public, private, and secret chats; secret chats are only between two people. This means that Telegram's private group chats are not e2e encrypted.

How does Telegram's encryption compare to other messaging systems?

Signal, as already said, has e2e encryption by default. Out of the major messaging apps, however, it appears to be the only one (at the time of this publication). Facebook Messenger is not automatically e2e encrypted. Like Telegram, one has to make the chat "secret."

Whatsapp, which Facebook owns, has end-to-end encryption for chats between family and friends, but the rules get murky when it comes to business chats. The app planned to change its business chat encryption in a policy update on Feb. 8, but due to backlash they pushed it to May 15.

Whatsapp messages between friends and family are end-to-end encrypted by default. However, your Whatsapp messages to businesses may not be end-to-end encrypted starting on May 15 if the business has granted access to third-party vendors, like parent company Facebook, for hosting purposes. When you start a chat with this type of business you’ll see a light blue message at the top explaining what kind of privacy you can expect. If the chat with the business is end-to-end encrypted, you’ll see a note at the top of the chat in yellow saying so.

To recap: Signal is always e2e encrypted. Whatsapp has e2e for friends, family, and currently business; some business chats will change in a few months. Facebook Messenger and Telegram are not e2e by default. One has to make the chat "secret" on either app for it to be so. In Telegram's case, that means only chats between two people have the potential to be e2e encrypted.

There you have it. Go forth, and choose your messaging service wisely. (Hint: Make it Signal.)