Privacy Is Either for Everyone – Or It Is for No One
Global Solutions Talk with Signal Messenger's Udbhav Tiwari
In this first episode of the Global Solutions Talk video interview format, Paul Nemitz, Fellow of the Global Solutions Initiative and Professor at the College of Europe, speaks with Udbhav Tiwari from Signal, the nonprofit, open-source messaging app recognized as the gold standard of end-to-end encryption.
Watch the interview
Interview transcript
Transcript edited for clarity.
Paul Nemitz: Welcome to the Global Solutions Talk. I’m Paul Nemitz. I’m a fellow of the Global Solutions Initiative and a law professor at the College of Europe.
I speak today with Udbhav Tiwari of Signal, the messenger. Udbhav had positions at Google and Mozilla previously.
Democracy and technology: How does Signal fit in there? What are your numbers of users compared to other messengers?
Udbhav Tiwari: Signal as an application is quite unique. It’s a nonprofit, open source project where all claims about the project are publicly verifiable. We are one of the very few widely used applications that open-source not just the client code—what runs on your app—but also the server-side code.
This means that everything that runs in the background, performing the service you use on Signal, is transparent. Signal is the gold standard of end-to-end encryption.
Approximately 3.5 billion people use the Signal protocol—the underlying technology for encryption—which is also licensed to other players, most prominently WhatsApp.
But Signal is different from WhatsApp. We don’t just encrypt the content of messages, but also protect metadata. For example, if you place a call on Signal, we don’t have a record of that call happening. We only know that two accounts communicated—not whether it was a call or message. In contrast, WhatsApp and other messengers store metadata that governments can request.
Signal offers encryption and privacy as a fundamental right for everyone.
Paul Nemitz: What are your plans for future expansion? And what about interoperability—like in email, where everyone can communicate with everyone? Would that be useful in your space?
Udbhav Tiwari: We definitely have plans for expansion. Just this year, we were the top app on iOS and Android in the Netherlands and Belgium, and top three in Italy. We even reached the top five briefly in the U.S.
This shows the rising need for private communication.
Regarding interoperability, it’s a big topic in Europe due to the Digital Markets Act (DMA). The DMA obliges large dominant platforms to offer interoperability to smaller ones, if requested.
Signal has been very clear: We don’t want to participate. Why? Because we wouldn’t be able to guarantee the same level of privacy.
For example, metadata—Signal doesn’t store it. But with interoperability, we’d have to share it with other services like WhatsApp, which would compromise our standards.
Imagine I want to call someone on WhatsApp through Signal—I would need to share that number with WhatsApp. That means both platforms have the metadata.
Group membership, profile names, images—all of this is currently invisible to Signal, and interoperability would break that model.
WhatsApp’s own proposal under the DMA uses the Signal protocol for security. So if another messenger wants to interoperate with WhatsApp, they must adopt the Signal protocol too. That shows the level of trust in our standard.
Paul Nemitz: So, you’re saying that interoperability should require that the higher privacy standard of the participating services must be adopted?
Udbhav Tiwari: Absolutely. And so far, there’s no technical solution that allows interoperability without sharing identifiers. It’s like sending a package to another country but using an address format only I understand—no one else could deliver it. That “address” is the metadata, and that’s what Signal protects.
Paul Nemitz: Let’s move to politics. How has the Trump government or US politics influenced your operations?
I heard Meredith Whittaker, your president, moved to Paris before the elections because she anticipated potential risks. Have you moved operations or funding outside the U.S.?
Udbhav Tiwari: Signal is still based in the U.S. We’re a nonprofit foundation, with another entity underneath that hires engineers and maintains the open-source project. That hasn’t changed.
Why? Because the politics don’t really affect our operations. We don’t rely on promises; we rely on code. Everything we change is reflected in our open-source repositories, available for anyone to verify.
People use Signal not because we ask for trust, but because they can verify what we do.
We recently rolled out post-quantum cryptography to prepare for potential quantum threats. And this is all done by a global project.
We know countries like Italy, the Netherlands, Belgium are strong markets for us.
We have a vibrant community on our forums and GitHub, contributing to what Signal becomes. It’s global and open source—anyone can help shape the future. Signal stewards that process, but the community drives it.
We believe privacy is either for everyone or for no one. End-to-end encryption is the bedrock of privacy, communication, and existing as a human in the digital age.
Paul Nemitz: Under U.S. law, I am told the government can force providers through a so-called ‘gagging order’ to provide content access and gag them from talking about it. How can the community be sure Signal isn’t under such an order?
Udbhav Tiwari: Because the code that runs Signal is open source.
If there were to be a gag order upon Signal, the way Signal would resist it is by not collecting the data in the first place.
Gag orders can force you to share information that you have and not tell anyone else. But what sets Signal apart is that we actually have a website — signal.org/bigbrother — and on that website, you’ll actually see multiple gag orders that we have received from courts and law enforcement agencies, which we have contested.
We’ve managed to get the court to unseal those gag orders, and then we put them up for the world to see.
And when you open those reports, you’ll see that there are only three pieces of information we can share:
- Whether you have an account or not,
- The date on which your account was created, and
- The timestamp at which your account last connected to the service.
Those are the only three pieces of metadata that Signal has.
And the verification for this is that it is also exactly what we’ve provided to courts — and we’ve gotten those orders unsealed to verify it.
So, our promises rely on transparency and on the public believing in what we do. In code, we do that by being open source on GitHub. In law, we do that by releasing gag orders and showing how that metadata is a tiny fraction of what every other messenger collects.
Paul Nemitz: WhatsApp and other big messengers are now offering AI conversations as an add-on. Is that something you could envisage, or are there any other messaging add-ons you’re exploring with your capacity to build networks for democracy?
Udbhav Tiwari: When it comes to AI, our president, Meredith Whittaker, and Signal have been quite clear that a lot of the ways AI is being deployed on devices today is magical thinking. It makes you believe it can do certain things, but many of those things are actually quite risky for privacy and encryption.
For example, both in Europe and the UK, one of the most hotly contested encryption debates of the last five years has been client-side scanning which is the idea that your device will scan content before it gets encrypted by the app.
We literally believe that is thought police — because your device is listening to what you’re doing, and if you meet certain criteria, it reports you — before it’s even encrypted.
That’s the kind of service AI is increasingly being used for in operating systems because it’s AI that scans your images, and AI that probabilistically determines if something is “problematic” or not.
So we’ve cautioned against this.
We think a lot of the hype around AI agents seems like an attempt to put your brain in a jar, connect it to communications, and suddenly it’s doing things on your behalf.
But the risks around that — the data they know about you, where that data is stored, and whether it can even be performed in an end-to-end encrypted way — are still very open questions.
We’ve seen WhatsApp recently announce something called “private processing”, where AI operations on messages are performed on the cloud in a private way, one that even Meta can’t see.
But we already think there are many differences there as well.
Paul Nemitz: Thank you, Udbhav. Good to have you — and good to have Signal in the world. Thank you very much for the conversation.
Udbhav Tiwari: Thank you so much for having me.
The views expressed in this interview are those of the speakers and do not necessarily reflect the views of the Global Solutions Initiative (GSI).