Proton Mail
SMS is as convenient as it is universal, allowing you to text anyone, regardless of their device or messaging app. But SMS messages are an open book, easily read by your mobile service provider, your gov't, and hackers. Here is why we don't recommend SMS: https://proton.me/blog/stop-using-sms
Why you should stop using SMS | Proton

Despite its popularity, SMS is a dangerously insecure way to send text messages. We examine why and discuss what you can do about it.

Proton
May 1, 2023 at 5:04pmMoa
Show threadcensored for “transphobia”May 1, 2023
@dibi58 @protonmail It’s perhaps inaccurate to say “SMS messages are not encrypted in any way”. IIRC there is at least transport layer security between the phone & the carrier, no? This is sometimes insufficient for the task at hand but at least you’re not vulnerable to very low tech attacks from someone using a radio scanner of some sort.
Show threadcensored for “transphobia”May 1, 2023
@protonmail @dibi58 The article also presents #Signal as an “SMS alternative”. But in fact Signal relies on SMS. Sure it builds a layer of security on top of it, but it’s still sketchy in light of these SS7 vulns. #Signal should be avoided for many reasons → https://github.com/privacytools/privacytools.io/issues/779
❌ Software Removal | Signal · Issue #779 · privacytools/privacytools.io

Problem with Signal Signal has copious privacy issues making it unfit for privacytools.io endorsement. Users are forced to supply a phone number to Signal (https://github.com/privacytoolsIO/privacy...

GitHub
Show threadcensored for “transphobia”May 1, 2023
@protonmail #SMS aids #security in one corner case: You send a passworded doc to someone. You need to get the password to them. When vis-a-vis is impractical, you can send the pw through a different channel than the doc. The more other channels you have, the harder it is to intercept. E.g. ⅓ of the pw sent by email, ⅓ by fax, & ⅓ by SMS. Evesdroppers need to intercept all 3 channels.
Show threadReay JespersenMay 1, 2023

@protonmail Hear hear.

The problem I (and I suspect many others) have is trying to get everyone I know on board with any one E2EE platform.

And given the basic security practice of not having apps on your phone that you don't need, I'm not about to get a handful of texting apps just to communicate to various friends opting to use one proprietary method over another.