Mobile phones have no default encrypted messaging

As mentioned in a previous blog post, your mobile device creates a vulnerability when it comes to protecting your online security. That does not mean there is nothing you can do to improve your privacy. For instance, you can replace your default SMS program with an encrypted messaging app without too much effort. By making this simple switch only the sender and recipient can read the messages, keeping them secure from any potential eavesdroppers. So let us look closer into Signal, an app that replaces your standard SMS messenger with end-to-end encrypted communication on your mobile phone.

Signal as a replacement of your default SMS client

It is important to note, though, that only messages to and from other Signal users are secured. Whenever you communicate with non-Signal contacts, it uses a regular SMS messaging service. The app does warn you when you try to send a non-secured message, and it tries to convince the receiver to make the switch to Signal. After all, by design, the app wants people to stop using their default SMS client on their mobile phones.

Also end-to-end encryption for voice and video calling

Text messaging is not the only security feature. Signal also provides end-to-end encryption for voice and video calling. The app can be used on Android and iPhone devices. A desktop version is at hand as well, but as with other communication applications, it needs to connect with the Signal app on your mobile phone. The desktop and the mobile apps synchronize messages with each other.

No access to messages in transit by third-party services

As said, all messages between Signal users have end-to-end encryption. This means that a message gets encrypted before sending it to the recipient. Only the intended receiver can decrypt the message. As such third-party services can not access messages in transit. Not even the Signal developers can access or view the content of your message; the only information kept on their servers and only until the message has been sent is some metadata. This log solely includes the user’s most recent connection to the app.

An open-source application using a secure messaging protocol

Many consider the Signal protocol as the most secure messaging protocol developed so far. It is based on various high-quality algorithms and cryptographic techniques, such as AES-256. X3DH, and Double Ratchet. . For further information, click on the provided link for those who are interested in a more technical explanation. As Signal is an open-source application, regular independent audits guarantee this encrypted messaging app keeps your messages private and secure. It has gained recognition for its commitment to open-source software and its dedication to transparency and accountability.

Widely utilized Signal-protocol for encrypted messaging

Some other popular communication apps, such as Facebook Messenger, WhatsApp (which is owned by Facebook), and Skype, also utilize the Signal protocol to ensure encrypted messaging. The difference compared to Signal is that these are closed source programs; which poses a potential danger of exposing your communication to their parent companies. History has shown that major companies such as Microsoft and Facebook are not the most reliable in guarding your online privacy.

A requirement to register your phone number

To begin using Signal, you must undertake a few straightforward actions. Download the mobile app from either the Google Play Store, the Mac App Store, or directly from the Signal website. An installation wizard will provide instructions to assist you throughout the installation process. Register your phone number by filling out an online form and verify the code sent to you via a text message. Previously Signal used to replace your default messaging app, and imported all your previous messages. At present it installs itself as another – safer – messaging application. Furthermore, the app will also have access to your contacts stored on your mobile device.

Your online privacy is not at risk

As the Signal app utilizes authentic telephone numbers for identifying your contacts, some people express disapproval towards this approach as it poses a risk to your online privacy. But you are the only person to access your contacts: Signal does not have the capability to view or access them. Additionally, once the app is installed and activated successfully, Signal operates independently without requiring any further contact details from your registered phone number. In simpler terms, you could easily register with a disposable or burner SIM card.

Some extra security features built-in

Alongside the encryption of your messages, Signal provides a couple of additional security features. When making voice calls you can verify the authenticity of the call through a pair of words displaying at the bottom of the screen when you make the call. Simply read these words out loud to the person you are communicating with. You can also enable a disappearing messages feature; you can set a time for deleting messages. And for both calls and conversations, there is session verification in order to prevent unauthorized individuals from intercepting these.

Use with dual SIM cards comes with restrictions

A fair amount of people have dual SIM smartphones. You can use Signal on these mobile devices, but there are some limitations in terms of functionality or compatibility. Sending and receiving encrypted messages is always used to and from the registered phone number. For plain SMS messages, these are sent and received by your default SMS app your and to the phone number they were addressed to. By long-pressing the Send button to send regular SMS, you can select the SIM card or phone number you want to use. See this article on GitHub for a more detailed clarification.

Replacement of default SMS texting to secure mobile communication

To secure your mobile communication, Signal offers strong encrypted messaging among registered users. This mobile application is user-friendly, has a great design, and can serve as a dependable substitute for your smartphone’s default SMS program. However, it is important to note that sending messages to individuals who do not use Signal is still insecure.