What is "Signal," and Why Do Privacy Experts Love It?

In our conversations about technology, one topic comes up more than any other: privacy. We've heard your concerns about who has your data, how it's being used, and how you can protect your personal information in an increasingly digital world. It’s a valid and important concern.

So, for the second installment of our "Tech Explainer" series, let's look at an app that was built from the ground up to solve this very problem. You may have heard it mentioned in the news or by a tech-savvy family member. The app is called Signal.

Tech Explainer: A Guide to Understanding Signal

So, What is Signal? The Big Idea

At its core, Signal is a free app for your smartphone and computer that lets you send text messages, share photos, and make high-quality voice and video calls, just like you would with iMessage, Google Messages, or WhatsApp. The one enormous difference is that Signal is designed, from top to bottom, to be the most private and secure way to communicate digitally available today.

What Makes It Better Than a Regular Text Message?

To understand the benefit of Signal, it helps to use an analogy.

• A standard text message (also known as an SMS) is like sending a postcard. As it travels from you to your friend, your cellular carrier and others involved in delivering it can, if they choose, read the contents on the back.

• A message sent through Signal is like a letter sealed in a tamper-proof steel briefcase. This is because Signal uses something called end-to-end encryption for every single message, call, and video.

This means that the moment you hit "send," your message is scrambled into a secret code. Only the person you sent it to has the unique "key" on their phone to unscramble it. No one in the middle; not your phone company, not your internet provider, and not even the people who run Signal, can read what you've sent. Your conversation is completely and truly private.

The "Clever" Part: Why Its Structure Matters for Privacy

This is what truly sets Signal apart from many other tech companies. Most companies that offer "free" messaging or social media services make their money by collecting your data and using it for advertising.

Signal is different. It is developed and run by the non-profit Signal Foundation. They are funded entirely by grants and public donations from people who believe in their mission of private communication for all. They have no corporate shareholders and their business model is not based on advertising. This means they have absolutely no financial incentive to collect or sell your personal data. Their only mission is to protect your privacy.

Who Uses It and Why?

Because of this intense, verifiable focus on privacy, Signal has become the gold standard for journalists, human rights activists, and government officials who need to ensure their communications cannot be monitored. However, it has also become incredibly popular with regular people all over the world who simply believe that their private conversations with family and friends should remain just that—private.

Quick Tech Tip

To use Signal, the person you are communicating with must also have the Signal app installed on their phone. When you first install and open the app, it will ask for permission to see your contacts. It will then show you which of your existing contacts are already on Signal, making it easy to start a secure conversation right away.

Tech Term Demystified: 'End-to-End Encryption (E2EE)'

This is the gold standard for digital privacy, and it's a term worth knowing. "End-to-End" means that a message is encrypted (scrambled into a secret code) on the sender's device (the first "end") and can only be decrypted (unscrambled) on the intended recipient's device (the other "end"). Any servers or systems in the middle that help transmit the message can only see the scrambled, unreadable data, not the content of your conversation.

Good News Byte

The technology behind Signal's encryption, called the Signal Protocol, is so well-respected and secure that other major tech companies have adopted it to improve their own apps. For example, the end-to-end encryption features in WhatsApp and the secure parts of Google Messages are also built using Signal's powerful technology. Signal has effectively raised the bar for privacy across the entire industry.

Did You Know?

One of the co-founders of Signal, Brian Acton, was also one of the original co-founders of WhatsApp. After he sold WhatsApp to Facebook (now Meta) and grew concerned about their plans for user data and advertising, he left the company. In 2018, he used $50 million of his own money to help create the non-profit Signal Foundation, ensuring that Signal would have a sustainable, non-corporate, privacy-focused future.

Your Turn to Start a Conversation!

You don't need to use Signal to appreciate its mission. This week, ask a tech-savvy friend or family member if they've heard of Signal and what they think about it. It can be a great way to start a conversation about digital privacy and learn more about why it's becoming such an important topic.

Wishing you a week of private conversations,

Steve