GEOFF BENNETT: Well, that Signal# group chat has also raised many## questions over just how secure# such messaging apps are and the## risks if government officials use# them on their personal devices.

Our Lisa Desjardins has more.

LISA DESJARDINS: That's right, Geoff.

The Signal chat among Cabinet member.. the growing use of personal phones and# downloaded apps by public officials who## handle sensitive information.

Attorney# General Pam Bondi has dismissed calls for## a criminal investigation into the Signal# conversation.

She says the app is secure.

Joining me now to discuss is Thomas Rid, professor# of strategic studies at Johns Hopkins University.

Thomas, thanks for joining us.

Signal is an app that many folks may know is used## for texting and messaging.

You just# type into your phone like other ones,## but can you explain why it's become the go-to# app for people handling sensitive conversations?

THOMAS RID, Johns Hopkins School of# Advanced International Studies: Signal## is the most secure..

So that means there's effectively a# tunnel of encryption going from your## phone all the way to my phone should# we talk via Signal or text via Signal.

And that means anybody listening# in between -- that could be Signal,## that could be AT&T or somebody# who owns a Wi-Fi network -- they## will not be able to see our text# messages, end-to-end encrypted.

LISA DESJARDINS: So then let's go# to what the attorney general is## saying.

Here are her words last night on FOX News.

PAM BONDI (R), U.S. Attorney General Nominee: I# think Signal is a very safe way to communicate.## I don't think foreign adversaries are# able to hack Signal, as far as I know.

LISA DESJARDINS: That's the question.

Are# foreign adversaries able to hack into Signal?

THOMAS RID: I think it's important# here to be very specific.

Technically,## the attorney general is correct# that so far we have no precedent## of an adversary ever hacking into Signal# the platform, as far as I'm aware of.

However, Signal is sitting on your phone# on just commercially available phones## like iPhones and Android devices.

We have many# examples of these phones getting hacked.

And,## of course, we should assume that# high-value targets like, for example,## the vice president or the secretary of# defense or the national security adviser,## that their phones are targeted by# some of the most capable adversaries.

So the phones are vulnerable.

Imagine literally# somebody looking over my shoulder at my phone.## They can see what's in it and what I'm texting# on Signal.

And so can somebody remotely reading## my screen.

That does not mean Signal has# been compromised.

It means the phone has## been compromised and you can look inside# the tunnel at the opening of the tunnel.

LISA DESJARDINS: Which foreign adversaries# are the most likely to be doing this?

THOMAS RID: That, of course, is# an invitation to speculate.

But## high up on the list would be China,# Russia, Iran, but many others as well.

LISA DESJARDINS: Now, in 2023, the Department# of Defense sent out a memo telling employees## that Signal should not be used for# information that wasn't already public.

It wrote that: "Mobile apps may contain# malware and have vulnerabilities."

And also:## "This is possible without the# user's consent or knowledge."

This goes to what you're saying about people# getting onto phones, foreign adversaries.

But## I want to ask you, do you have a sense of how# seriously the federal government structure,## employees in the federal government have been# taking that warning about Signal?

Is it common## for people to use it?

Or do you feel like# there's a culture of not using those apps?

THOMAS RID: I mean, let's be very# specific.

Signal, for most normal people,## for confidential, for conversations# and phone calls that are confidential,## that are just private -- we call it private# in public life.

Signal is the best you can do.

However, the government, of course,# has more secure systems available for## classified information, like when you're# planning a military operation.

So Signal## should not be used, very clearly,# for any classified information,## because it doesn't even reside in# classified -- in a classified environment.

So while it is the safest you can do as a# commercial, private person, and indeed as a## government employee outside of the classified# system, it is not OK to use it for classified## content.

That is a fundamental difference# that I think we should be very clear about.

LISA DESJARDINS: Something else about Signal# is that it's designed so that messages can## disappear very quickly, an hour after they're# written, if the users choose to do it that way.

Can you help us with how that overlaps or if# that's a problem with federal records law,## which requires these conversations to be kept?

THOMAS RID: Federal records law, indeed, requires# information to be kept in an archive for future## use.

And, of course, if you set your disappearance# time to something quite short, one minute, five## minutes, or even just a day, it will be very hard# to keep track because messages just disappear.

I'm not sure there's a process in place for# capturing Signal traffic for archival purposes.

LISA DESJARDINS: Thomas Rid,# thank you for giving us some## answers.

Still more questions# out there.

We appreciate you.

THOMAS RID: Thank you.