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

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 to make your messaging impenetrable.

Signal's role in global privacy in 2025

Signal has been in the news lately, at the center of multiple scandals.

Signal has consistently refused to weaken its encryption or share data with governments. As other platforms cooperate with surveillance demands, Signal’s commitment to privacy makes it a stronghold for secure communication.

Note: When we talk about surveillance, we mean the practice of governments or companies watching your online activity. Signal helps block that by making it so they can't see your actual messages.

For example, during protests or high-risk journalism, activists and reporters worldwide rely on Signal to ensure their conversations remain safe from eavesdropping.

Why end-to-end encryption is so important

End-to-end encryption means only you and the person you’re communicating with can read your messages. Even Signal can’t see what’s being sent. And if someone intercepts the message in transit, it will be protected and unreadable.

This differs from regular messaging apps that might encrypt data between you and their servers, but can still access your content on the server side.

End-to-end encryption, like mailing a letter in a locked box that only your friend has the key to. Nobody — not even the mail carrier — can peek inside. This makes it an essential privacy and security feature to look for in a messaging app, and Signal is a great one to choose.

The importance of open source software

Another important bonus of Signal is that it is open-source, which means its code is public. Anyone can inspect it, making it a public recipe of the tech you’re using: anyone can look at it and make sure there’s nothing harmful or misleading inside.

Open source code ensures there are no hidden backdoors for hackers or governments, for example, to break encryption and access the contents of your communication.

Other proprietary apps may claim to be secure, but without open source code you have to trust their word. With open-source software, experts can independently verify security claims.

Signal’s approach to metadata protection: No logs

Metadata is data about your data. It includes information like who you messaged, when, and how often — even if they can’t see what was said. Think of metadata like the envelope of a letter: it shows who sent it, when, and where it's going.

Signal stands out by not storing this kind of metadata. That means they can’t show your communication patterns even if records are demanded or leaked.

Metadata is now the raw material of mass surveillance programs, so learn more from the Nym team about how to protect your metadata while you’re online.

What Signal doesn’t protect: Network-level metadata

Despite its strengths, Signal does not hide your metadata at the network-level. Surveillance systems can still detect that you’re using Signal, when, and possibly even where and with whom you’re talking to.

Even if the message is encrypted, patterns can emerge from traffic timing and size. This potentially reveals sensitive information over time.

While people watching your internet connection can’t read your actual messages on the app, they might see that you sent a message to someone at 8:42 PM every night from your hometown. That’s still revealing.

Strengthening your Signal app with Nym’s mixnet

Genuine privacy online these days requires a suite of tools. With NymVPN’s Anonymous mode, you can connect your device to a Noise Generating Mixnet, a novel privacy layer that masks your network-level metadata.

A mixnet sends your internet traffic through multiple encrypted relays where your data is mixed with the data of other peoples’. This makes it very difficult for surveillance to find your communication patterns.

NymVPN thus effectively protects all of your metadata while using Signal. It hides who you are, when you're sending messages, and where you're sending them to — on top of what’s inside the message.

So if Signal is the locked box with your message, a mixnet is like sending that box through a maze of tunnels with other locked boxes, which all look the same, so no one knows which came from you. Explore how encryption and network-level obfuscation work together.

Signal and geographic surveillance concerns

In some regions, simply using Signal could trigger surveillance due to strict internet controls. While the message itself remains private, your IP address and connection patterns can still be monitored.

Pairing Signal with tools like NymVPN can help shield your usage, even from nation-state observers. This is especially important for users in restrictive countries, human rights defenders, journalists, and people struggling against authoritarian governments.

Nym’s best practices for maximum Signal privacy

Signal is powerful, but using it the right way can make a big difference in how private you really are. These tips help you minimize metadata exposure and keep your conversations secure.

• Always verify your safety numbers with contacts
• Use disappearing messages for sensitive chats
• Turn on registration lock to prevent account hijacking
• Pair with NymVPN to protect network metadata
• Keep your app updated to receive the latest privacy enhancements
• Disable cloud backups for message content and app data, if applicable

Enhanced Privacy Is Within Reach

Signal is one of the best private messagers available, but it’s not invincible. For complete privacy, pair it with a VPN like NymVPN to shield your metadata, protect against surveillance, and stay anonymous online.