"[T]he main thing that people need to understand about Signal is that messages are encrypted from my phone to your phone in such a way that Signal can't read them as they go through their servers. The government could not read them off of Signal servers even with a warrant, even if they really wanted to. But if somebody has access to your phone, they can read those messages the same way you can by looking at them with their eyeballs because the messages have to be decrypted for you to read.
Now, there are a lot of ways that you can get access to somebody's phone. You can look over their shoulder while they're reading their messages, right? You can find out their password and unlock their phone, right? You can use forensic tools that police have like a Cellebrite or a break-in device to unlock phones, and then you can read the messages that way. You can also use malware. Installing malware on somebody's phone is a way that governments often gain access to people's private encrypted communications. Things like Pegasus malware or they're recently written about malware from Paragon Solutions that was going after WhatsApp messages, which was also end-to-end encrypted.
A concern about national security folks using these devices for the communications is that it makes it much more likely that their devices will get targeted by malware. And there's a lot of countries that have espionage capabilities that have the capability to target people's phones that would be very interested in knowing what Pete Hegseth is talking about, or what other high-level cabinet officials are talking about. So that makes for a very juicy intelligence target for foreign intelligence, and I think it's safe to assume that's something that many countries are now going to be going after."
