What is Signal? A beginner’s guide to secure messaging

Nym explains what makes messaging apps private, and where you’re vulnerable

June 5, 20257 mins read

Signal is a free, open-source messaging app known for its strong end-to-end encryption. You can send messages, voice notes, images, and even make encrypted calls over data without anyone — even Signal — seeing your content.

With rising concerns over government surveillance and tech companies harvesting data, Signal is the go-to choice for people who need genuinely private and protected communications. But is it as secure as people say?

Absolutely! But when it comes to surveillance, even the best encrypted messengers have a vulnerability: metadata traces. Nym’s cybersecurity experts explain why and how you can pair Signal with mixnet protections like NymVPN to make your messaging impenetrable.

Try NymVPN for free today

Nym's Noise Generating Mixnet

Signal encrypts your messages. Not your metadata.

Nym hides your network activity too.

Try NymVPN free

Signal: FAQs

Not by default. To fully anonymize your IP, you can route Signal traffic through a privacy-focused network like NymVPN.

Yes. Signal’s group messaging is end-to-end encrypted, ensuring that only members of the group can see the messages—even Signal can't access them.

No, Signal voice and video calls use the same end-to-end encryption protocol. If someone tries to intercept it, they would only see scrambled data.

No. Signal does not store your contacts, message history, or logs. All data stays on your device, and not even Signal has access to it.

Yes, many journalists, lawyers, and doctors use Signal for secure communication. Just ensure your device itself is not compromised.

Yes, Signal currently uses your phone number as an identifier. However, the app does not store this data in a way that links you to specific messages.

Open-source code allows independent experts to verify the app’s security, ensuring there are no hidden vulnerabilities or backdoors.

Unlike many encrypted apps, Signal doesn’t store user metadata or serve ads. It’s also operated by a nonprofit and doesn’t monetize your data.

Signal is available on iOS, Android, Windows, macOS, and Linux. Your messages stay encrypted and synced across all devices.

About the authors

Benjamin Nemeroff

Ben is a core member of Nym’s marketing team. He writes about privacy, security, and VPNs, helping users protect themselves from tracking and surveillance.

Casey Ford. PhD

Technical reviewer

Casey is the Head of Communications, lead writer at Nym, and editorial reviewer at Nym. He holds a PhD in Philosophy and researches the intersection of decentralized technologies and social life.