Signal App’s Unusual Kind of Endorsement
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Welcome to Tech News Briefing. It's Wednesday, March 26th. I'm Victoria Craig for The Wall Street Journal. Signal is the app for spies, journalists, and apparently senior White House officials. What is it? And is your data safe there? Then, putting a car through a round of stress testing takes Ford about 15 hours. An AI-trained prediction model, though, takes just 10 seconds. We'll chat carmaking in the age of artificial intelligence.

First, if it's good enough for the White House, is it good enough for me? That seems to be the question many people are asking about the messaging app Signal. Interest has skyrocketed on mobile app stores since The Atlantic reported senior White House officials discussed plans on Signal to launch airstrikes in Yemen. Controversy has swirled around administration officials' decision to use the app for military operation discussions.

But if you're confused about what exactly Signal is and how secure it can be, WSJ tech reporter Sam Schechner has the answers. For listeners who have never used it before, who have never heard of Signal until today...

What is it used for? Signal is a chat app that works on your phone or your computer, actually, to have a desktop app. It's kind of like WhatsApp or iMessage, and it's encrypted. It's end-to-end encrypted. And so it's very popular with journalists like me for talking to sources, but also people who are

privacy conscious, including, you know, intelligence officials on their personal devices. I can vouch from personal experience, use Signal too. And we'll get to the intelligence aspect of this, but just explain first for people who aren't necessarily familiar, what does encrypted messaging mean exactly? That's a great question because there's things it means and there's things it doesn't mean. What they use is something called end-to-end encryption. So it's encrypting your message in transit.

So when you type something into the app on your phone, obviously you can see it. It's not encrypted. And then what the app does is it scrambles it in such a way that it can only be read by the other person's phone. And that scrambled message transfers along the internet in that scrambled way so that if somebody were to intercept it, which is easy to do on the internet, it's gibberish. There's nothing to see. And that keeps your message private until it gets to the other person's phone, which

unscrambles it. The way that Signal scrambles your messages is pretty robust. They publish it as open source and security experts say it has yet to be broken.

That's pretty incredible when you think about it, because so many messaging apps have been hacked before. Consumer data is all over the Internet. How do we know that, especially given the sensitivity of the discussions among these government officials, these top government officials at the White House,

How do we know that it's safe? Is it vulnerable to hacking? Signal, the algorithm itself, is, according to experts, safe. And in fact, it's so safe that WhatsApp uses the same encryption algorithm. They use Signal's guts, basically, to do the end-to-end encryption of WhatsApp. The issue is that

in order to be read, it has to be decrypted, right? Like on your device, it's not encrypted when you read it. It's in English or whatever language you speak. And likewise, when you type it in, it's not encrypted. And what's vulnerable are your phones, the endpoints. And that's the weak link when it comes to ending encryption. And that's why government officials aren't supposed to use personal devices to handle classified information. No matter what app they use, if your phone gets hacked, then...

then, of course, the hackers can read what's on your phone. So what do government officials use for this kind of communication usually? Normally, conversations concerning classified military plans like striking foreign targets are supposed to

only happen in what the U.S. government calls secure compartmented information facilities or SCIFs. And these are rooms that are specially designed to prevent conversation from being spied on. They have technical things about them that make it hard to be spied on and they have secure communications inside. And you're not supposed to bring your cell phone inside that room because a phone can be hacked. Walk us through who owns and operates SCIFs.

Because that's also a question for users when they start using a new app is who ultimately has access to my user data? Signal is owned by a nonprofit called the Signal Technology Foundation. So that doesn't necessarily tell you that much. It was started by a cryptographer, an entrepreneur named Moxie Marlinspike, who was very interested in private communications. And actually, the foundation was set up by Moxie along with Nucleus.

initial funding from WhatsApp's co-founder, Brian Acton. And it's still run by that foundation, which is funded largely by grants and donations. What the foundation says is that that actually should give you some reassurance that they're not looking to monetize your data. And what Signal says is that they actually keep almost no metadata about what its users are doing on the app. And that's an important distinction because there are apps that are encrypted end-to-end, but

That's the content of your message that's encrypted, not the fact that X phone number sent a message to Y phone number or X internet address sent a message to Y internet address. A company might actually have a network of who messaged who when, and that tells an adversary a lot without even knowing the content of the messages.

Signal doesn't keep any of that information. It's all purged. And so if they're hacked or if a government comes to them with a subpoena asking for information, they can only provide two pieces of information, they say. The Dayton account was created and the last time it was used, but not when and where and to whom messages were sent. That was Wall Street Journal tech reporter Sam Schechner.

Coming up, from clay models to computer stress tests, we'll hear how Ford is speeding up its car-making process thanks to artificial intelligence. That's after the break. This episode is brought to you by State Farm.

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Here's a good quiz night fact for you. Before we ever hop into the driver's seat of a brand new car, a life-size clay model is first painstakingly sculpted by a designer. It's then passed on to engineers who run lengthy stress tests to make sure it's safe. At least, that's how carmaking still originates at Ford.

But now, those same designers are getting a leg up from AI to cut down on development time. Wall Street Journal reporter Isabel Busquets told me more about a recent conversation she had with the carmaker's director of AI.

I was genuinely surprised, Isabel, to read in your story that Ford engineers actually create life-size clay versions of their car designs before they ever begin the manufacturing process. The company's director of artificial intelligence, though, has some ideas about how to make that entire process less time-consuming and more efficient by leveraging AI. Walk us through that.

These designers, they also really like to sketch, but the problem with a sketch is that it's two-dimensional. And what some of these AI engines can do now is you can give it a two-dimensional picture, a two-dimensional sketch, and it can generate essentially a three-dimensional model of a car.

And from there you can continue to make tweaks to it, the roof, the windows, et cetera. But yeah, getting from the 2D to this fully formed 3D model without having to do the whole clay sculpting process does seem like it can speed things up. They do not want to get rid of clay, totally. They still love being able to feel and see that. The AI is basically just looking to accelerate some parts of the process here.

part of the reason it's taking them so long is because there's the design process where they're building the clay model of the car, they're figuring out what they want it to look like. And then there's also the engineering team then comes in and has to run stress tests. They're using AI models that essentially can predict some of how the car will react in those stress tests a lot faster than it would traditionally take to run the stress test. In the past, one run might take 15 hours, but now

Now this AI model can predict what the output of the stress test will be in 10 seconds. Being able to speed that up a lot is really helpful for them. They're really looking for efficiency and speed right now, especially to compete with some of the Chinese automakers who are just rolling out new models really fast.

So what AI platforms is Ford leveraging? They told me they're using the OpenAI models, the Google models, Anthropic. They really like open source models. So those include Meta's Llama model and the DeepSeek model. In the past, companies have been kind of hesitant to use DeepSeek. They do like it because it's open source, which means you can build and customize a lot on top of that.

Cost is always a factor in some of these new technological innovations, and these AI models are powered by graphics processing units or GPUs. Brian Goodman told you that the company uses NVIDIA's chips, but cost, of course, is a hurdle to that. And I love the way he characterized it because he compared it to trying to get Taylor Swift tickets.

We had NVIDIA's developer conference recently, and they unveiled a whole new slate of chips. So how is Ford thinking about the need to use those chips? Ford's strategy is essentially to build its own data centers and buy its own GPUs, and it's been doing that for a while.

Ford has been coming to this NVIDIA conference for the last 10 years. They have a close relationship with NVIDIA. And they've been buying these NVIDIA chips and filling their own data centers with them. And I think they feel like that gives them the opportunity to not be reliant on the cloud providers. They don't have to wait for that capacity. They don't have to worry about what that capacity might cost today versus what it might cost tomorrow.

They sort of have their set costs. And yeah, they're continuing to buy GPUs and build out that infrastructure. That was WSJ reporter Isabel Busquets. And that's it for Tech News Briefing. Today's show was produced by Jess Jupiter with supervising producer Emily Martosi. I'm Victoria Craig for The Wall Street Journal. We'll be back this afternoon with TNB Tech Minute. Thanks for listening.