Why You Should Use Signal for Confidential Business Communication

What is Signal?

Signal is an encrypted messaging app developed by the nonprofit Signal Technology Foundation. The organization’s mission, as stated on its website, is “to develop open source privacy technology that protects free expression and enables secure global communication.”

What can Signal do?

Signal is a cell-phone-based messaging app. If you already use messaging apps, you may already be familiar with a lot of Signal’s features, including these:

• Video and voice calling
• Status updates
• Self-destruct messages
• Group chats
• File sharing

The Signal app shares much of the look and feel of WhatsApp, Messenger, Telegram and other platforms. Like those apps, Signal is linked to a cell phone number.

How does Signal protect privacy?

Signal uses end-to-end encryption to prevent others from seeing the contents of your messages or hearing your calls. It creates an encryption key for every action you take using the app and sends the decryption key only to the people you’re interacting with. The key is stored only on the recipient’s cell phone, not on Signal’s servers. [Learn about using data encryption in the cloud.]

To do this, the app uses the Signal Protocol, which is not exclusive to the Signal app; rival private messaging apps also use it but in a less private way than Signal does. Consider these examples:

• WhatsApp started using the Signal Protocol in 2016, but unlike Signal, it collects user data, such as phone numbers and locations, which it then shares with Google.
• Messenger uses the Signal Protocol only for its “Secret Conversations” function, where users must manually activate encryption. The protocol doesn’t work on group chats. Parent company Meta also collects data from users like its subsidiary WhatsApp does.
• Skype activates the Signal Protocol only for “Private Conversations,” similar to Messenger. Skype also collects data from users.

What makes Signal different?

Signal stands out from competing messaging apps for several reasons. For example, the program recognizes a user only by their cell phone number. Data encryption is the default position on Signal, meaning users don’t have to switch it on, unlike with WhatsApp, Messenger and Skype. 

Signal doesn’t store or retain any messages, videos, documents or other data transmitted over the app’s network. Furthermore, the program cannot decipher any data in transit. This helps ensure your private information — professional or personal — stays confidential.

There are no ads or trackers on Signal, either. There is no way for private companies or public agencies to advertise on the platform (although they are not barred from the app). At the very least, this means the app isn’t tracking your user behavior and giving this data to third parties that want to exploit that information for ad targeting.

These are some of Signal’s other notable security features:

• Relay calls: This function hides your IP address from contacts during video or voice calls. (An IP address can reveal an approximate location.)
• Sealed sender: This feature hides sender or caller ID by concealing metadata such as the user’s IP address or phone number. Only the receiver can see this information.
• Signal PIN: This tool encrypts your profile and account data and stores it on Signal’s servers. Such information is then accessible only via the PIN you set. Signal doesn’t know your PIN and can’t reset it if you forget it.
• Signal Payments: Via an integration with MobileCoin, Signal users can send and receive crypto payments from their contacts without revealing financial or personal information.
• Screen security: This feature stops Signal from being shown in apps such as Microsoft Phone Link, which can mirror your phone screen on a PC.
• Face blurring: This function blurs the faces of people in photographs you share on Signal to protect their privacy.

How does Signal compare to Telegram and other apps?

In the eyes of many experts, Signal is far more secure than rival platform Telegram, which was previously thought to be the most secure widely available messaging app. Telecom and security expert Paul Hanner, chief technology officer of communications company Metavoxx, said Telegram isn’t as secure as people think it is. 

“Telegram does not use end-to-end (E2E) encryption by default and not at all in groups, so it is necessary for both parties to set up a secure chat to enable full E2E encryption,” Hanner told business.com.

“On the other hand,” he continued, “WhatsApp and Signal both encrypt messages end-to-end, over the local network and internet, so they can’t be intercepted and read. And with the inclusion of [two-factor authentication] using a PIN, Signal also protects your account from being breached by SIM card cloning.”

Ultimately, Hanner said, “Signal wins on end-to-end encryption, and Telegram has the lowest security, with WhatsApp in between.”

Why is Signal beneficial for confidential business communication?

Compared with other private messaging apps, Signal’s combination of privacy and security features should give business owners and other professionals the confidence that it’s a secure means of exchanging confidential data. These are the top reasons Signal can be beneficial for sharing private business information:

• Complete encryption: All messages and calls are encrypted from end to end, ensuring that only you and your recipient can read, listen to or watch the contents of a message. No one at Signal can decrypt the message, nor could a hacker do so in a man-in-the-middle attack. 
• Secure account ownership: Signal’s “Registration Lock” feature protects your account when you switch phones. You need to register a unique PIN to connect your Signal account to a new phone. This prevents unauthorized access even if someone gets access to your phone number or SIM card. If you forget your PIN, you lose your account, because Signal doesn’t know your PIN. Registration Lock also securely transfers your contacts and conversations to your new cell phone.
• Lack of identifying markers: Other than your cell phone number, Signal knows nothing about you. Even if the app did, the platform doesn’t keep metadata on whom you talk to or message. Signal has nothing to sell to advertisers or hand over to governments, even under a court order.
• Open-source platform: You may not be a programmer or coder, but lots of people are. The code that powers Signal is open-source, so anyone, including someone you hire, can scrutinize its code to ensure there are no hidden vulnerabilities or backdoors. In other words, your in-house developers can work to make the app even more secure than it already is.

As a business owner, there are many practical reasons why you’d want to use an app such as Signal for sharing confidential information. Maybe you’re exploring a merger with a rival company and you and the fellow CEO want to keep these early talks on the down low. Perhaps your executive team is developing a new product and you don’t want any details to leak. Or maybe there is new data you need to share without leaving a paper trail. Whatever the case, Signal is ideal for such scenarios.

Does Signal have downsides?

No app is perfect, and you should keep some vulnerabilities in mind when using Signal, Hanner said. He recommended taking additional actions to protect confidentiality to the fullest extent possible.

“In addition to locking your phone, you should also use Signal’s screen lock just in case someone steals your phone in an unlocked state,” Hanner said. “If that happens, there’s no barrier stopping the thief reading the contents of your messages. Reporting your phone lost or stolen to get the SIM deactivated does not deactivate the Signal app.”

Furthermore, despite Signal’s strengths, “nearly all countries now require SIM registration,” Hanner added. “So even with an encrypted message, the metadata alone will give away your identity and who you are speaking to. He advised adding another layer of security by using a virtual private network (VPN) to conceal your IP address. However, you’ll have to make sure that the VPN doesn’t keep logs of your data.

Who has endorsed Signal?

Signal has strong brand advocacy among its users, many of whom are famous — or infamous — precisely because of their communication habits.

• Edward Snowden: In 2021, the notorious whistleblower responded to a Twitter user who questioned whether Signal could be trusted and if there was a reason to use it. “Here’s a reason: I use it every day and I’m not dead yet,” Snowden replied.
• Jack Dorsey: In 2019, Dorsey, founder of both Square and Twitter, declared in a tweet, “I love @signalapp. It’s come such a long way!”
• Elon Musk: The current owner of Twitter (which he recently rebranded to X) told his followers in 2021, “Use Signal.”

Signal itself once pointed out on Twitter that even Mark Zuckerberg uses its app when the Meta CEO could just use his own Messenger app instead. If these tech-savvy public figures are trusting Signal for their confidential communications, business owners may be wise to do so as well.

What are some alternatives to Signal?

Signal is a great tool for confidential communication, and it’s widely available — but will that always be the case? The company’s president, Meredith Whittaker, told The Verge in 2022 that it would discontinue service in any country where the government tried to interfere with its encryption and privacy measures.

Hanner predicted that “open-source encrypted and [peer-to-peer] message apps will at some point be banned because they offer real anonymity and security to users.” As an alternative, he suggested business owners carry out communication over messaging apps that don’t require a cell phone number. That’s because “these kinds of message apps when used with a VPN make the metadata meaningless because it can’t be attached to an identity,” he said. 

“They also offer E2E encryption and are classed as Web 3.0 and in some cases [peer-to-peer], so they don’t rely on a single corporate-owned central server that all messages pass through,” he added. Products on the market include Element, Session, SimpleX and Delta Chat. They allow many of the same video, voice-calling, messaging and file-sharing features available on Signal, but they use decentralized networks of servers.