Table of contents
- What is Signal: definition and philosophy
- How Signal works
- Key features of the Signal app
- Is Signal really free? How is it funded?
- Why choose Signal: advantages over other apps
- How to install Signal
- Signal’s limitations and challenges
In an era where digital privacy is increasingly at risk, the need for tools that truly protect communications is growing. Among the most reliable solutions is Signal, an instant messaging app known for its radical approach to security and transparency.
Used by activists, journalists, IT professionals, and privacy-conscious users, the Signal app has carved out a prominent role in the world of secure messaging.
In this article, we’ll explore what Signal is, how it works, its main features, how to install and use it on different mobile devices, and why it’s a valid alternative to more popular but less transparent apps.
What is Signal: definition and philosophy
Signal is a free app for instant messaging and voice calls that uses end-to-end encryption to protect conversations. This means only the sender and recipient can read the sent messages, making it impossible for third parties – including hackers, network providers, and even Signal itself – to access message contents.
Unlike many competing apps, the Signal mobile app is developed by a non-profit foundation, the Signal Foundation, which operates without commercial purposes and does not collect personal data for advertising. Its source code is completely open source, meaning anyone can inspect, modify, and contribute to its development. This transparency is one of the platform’s strongest assets.
How Signal works
Installing and starting to use the app is simple and fast. It is available for all major operating systems, including Androidand iOS, and can be downloaded from the official app stores. During registration, users are required to provide their own phone number as an account identifier, but Signal does not store or associate that number with any public or visible profile.
All communications – text messages, voice messages, voice calls, video calls, media files, stories that disappear after 24 hours, and disappearing messages – are protected by end-to-end encryption, enabled by default settings. The app does not require any manual encryption activation, reducing the risk of user errors.
Key features of the Signal app
The Signal app offers several features designed to enhance both security and the user experience:
1. End-to-end encryption
The most important feature of Signal. All messages and calls are protected using modern encryption based on the Signal Protocol, which is also used by other platforms (like WhatsApp), but forms the core of the entire Signal infrastructure.
2. Disappearing messages
Users can set a timer after which messages self-destruct. This is especially useful in contexts where confidentiality is critical.
3. Temporary stories
Recently introduced, these are multimedia contents that disappear after 24 hours, similar to those on other platforms, but with the advantage of full data protection.
4. Secure voice and video calls
Signal allows for secure voice and video calls, ensuring that content is never transmitted in readable form through external servers.
5. Protected groups
Group creation does not reveal phone numbers to other participants unless authorized, and all group messages remain encrypted.
6. No advertising, no tracking
Signal does not use cookies, trackers, or any advertising systems. Your experience remains private and uncompromised.
Is Signal really free? How is it funded?
Yes, Signal is completely free. There are no premium versions, no ads, and no paid plans. It is mainly funded through voluntary donations and grants from organizations committed to digital privacy. This non-profit model ensures no conflict of interest and promotes development focused on user needs.
Among its key supporters is Brian Acton, co-founder of WhatsApp, who left the company after its acquisition by Facebook and co-founded the Signal Foundation, contributing an initial donation of $50 million.
Why choose Signal: advantages over other apps
While many other messaging apps exist, few offer the same level of security, transparency, and privacy respect as Signal. WhatsApp, while using the same encryption system, is owned by Meta and collects a vast amount of metadata. Telegram, though very popular, does not enable end-to-end encryption by default.
Signal, on the other hand:
- does not store metadata on conversations,
- has no ads,
- does not track users,
- publishes the full source code for every version.
For these reasons, Signal is recommended by organizations such as the Electronic Frontier Foundation (EFF), Amnesty International, and by experts like Edward Snowden and Bruce Schneier.
How to install Signal
On Android:
- Open the Google Play Store.
- Search for “Signal”.
- Tap “Install”.
- Open the app and follow the steps to verify your phone number.
On iPhone:
- Open the App Store.
- Search for “Signal”.
- Tap “Get”.
- Verify your number and set your privacy preferences.
Signal is also available for desktop (Windows, macOS, Linux), but requires linking to an already active mobile account.
Signal’s limitations and challenges
Like all technologies, Signal has its limitations. Requiring a phone number can be a barrier for users who seek deeper anonymity. Additionally, some features like bots or cloud sync are deliberately omitted to preserve privacy.
Its user interface, while improved over time, remains more minimalist than alternatives like Telegram or Messenger. However, this aligns with the open source and privacy-first philosophy of the Signal Foundation.
Conclusion
In a digital world dominated by ads, surveillance, and privacy violations, the Signal app offers a concrete and effective response. Secure, open source, free, and developed by a non-profit foundation, Signal enables users to send messages, make calls, and share files with maximum confidentiality.
Anyone who values digital freedom should at least try this messaging app built around the fundamental rights of its users—not around data exploitation.
Questions and answers
- What is Signal?
It’s an instant messaging and voice call app that protects user privacy through end-to-end encryption. - Is it free?
Yes, it’s completely free and ad-free. It’s funded through donations. - How does the encryption work?
It uses the Signal Protocol to encrypt all messages and calls so that only the sender and recipient can access them. - Is it open source?
Yes, both the client and server have publicly available source code. - Does it work on Android and iPhone?
Yes, it’s available for both major mobile operating systems, as well as for desktop. - Does it collect my data?
No, Signal does not collect personal data or store metadata from communications. - Can I use it without a phone number?
A number is currently required to register, but it’s not visible to other users. - What are disappearing messages?
They are temporary messages that automatically delete after a set period. - Does it have stories like WhatsApp or Instagram?
Yes, it has stories that disappear after 24 hours, protected by the same encryption. - Why is it recommended by security experts?
Because it offers high levels of protection, transparency, and independence from commercial interests.
