Security12.01.2021

WhatsApp compared to alternatives Telegram and Signal

Whatsapp on phone in hand

Facebook recently issued a notice within WhatsApp informing users that they need to accept its updated terms of service and privacy policy or lose access to the app from 8 February.

The ultimatum resulted in a backlash against WhatsApp on social media, with many people looking for alternatives to the popular instant messaging app.

Facebook has assured that the change only applies to business messaging on WhatsApp, but this hasn’t stopped people from checking out other platforms and more carefully scrutinising the data that Facebook collects through WhatsApp.

Telegram is a popular choice as a WhatsApp alternative due to its rich feature set. Its claims that it is more secure than WhatsApp has also helped drive adoption.

Signal is another alternative that has received a lot of attention after being endorsed by Elon Musk and Edward Snowden.

However, Telegram and Signal are not the only instant messaging apps that offer an alternative to WhatsApp’s dominance.

WeChat, Viber, Kik, Line, and even Google Hangouts or Microsoft’s Skype are options for people who want to use a messaging service outside of the Facebook ecosystem.

This comparison will focus on messaging apps that can be used as a drop-in replacement for WhatsApp and offer equivalent or better security and privacy features.

For that reason we will not be looking at WeChat, Viber, Kik, Line, Hangouts, or Skype as they either do not offer end-to-end encryption or they gather even more of your personal data than WhatsApp does (based on Apple’s App Store privacy labels).

Security vs privacy

First, it is necessary to make a distinction between a messenger’s security features and its privacy policy.

WhatsApp offers exemplary security, including:

  • End-to-end encryption by default using the Signal Protocol — the same encryption scheme as Signal.
  • Only holding encrypted messages for as long as it takes to deliver them, then deleting the messages from their servers.

WhatsApp’s main weakness security-wise is the way it handles cloud backups for your messages. If you choose to enable cloud backups, your messages are either stored on Google’s servers (on Android), or Apple’s (on iPhone) and you rely on whatever encryption they use.

Privacy-wise, WhatsApp is the weakest of the three apps compared in this article.

WhatsApp gathers much more personally-identifying information than Telegram and Signal. It is also part of the Facebook ecosystem and there are legitimate concerns over the amount of data that might be shared between WhatsApp and Facebook’s other services.

When it comes to security, Telegram takes an entirely different approach to WhatsApp and Signal:

  • Chats are not end-to-end encrypted by default. Optional secret chats are available.
  • Telegram has rolled its own encryption algorithm rather than using standard industry-recognised schemes. Information security professionals warn that this is dangerous as the protocol has not been vetted by people outside Telegram.
  • Messages are stored on Telegram’s servers where you can access them via various client apps at the same time (e.g. smartphone, PC, tablet).
  • You can choose not to expose your phone number in Telegram.
  • Telegram notifies you when contacts sign up to the app. Signal does this too.

Messaging app feature comparison – WhatsApp vs Telegram vs Signal

Ignoring Facebook’s insatiable need for ever more user data for the moment, let’s focus on the key technical and design differences between WhatsApp, Telegram, and Signal:

WhatsApp vs Telegram vs Signal
Feature WhatsApp Telegram Signal
End-to-end encryption Yes (Signal Protocol) Only in secret chats (MTProto) Yes (Signal Protocol)
Group chats Max. 256 people Max. 200,000 people Max. 1,000 people
Voice calls Yes Yes Yes
Video calls Yes Yes Yes
Group voice calls Max. 8 people Thousands of people Max. 5 people
Group video calls Max. 8 people Not yet available Max. 5 people
User ID Phone number only Phone number or username Phone number only
Cloud storage / backups Backups to Google or Apple servers available Encrypted messages stored on Telegram servers. Telegram has keys to decrypt them. None / Manual backups only

Messaging app privacy labels in the Apple App Store

Apple recently rolled out App Privacy Labels on the App Store, requiring developers to disclose what information they are gathering about users and how they intend to use it.

According to these labels, WhatsApp collects a significant amount of data which may be linked to your identity.

The data it collects is divided into several categories: developer’s advertising or marketing, analytics, product personalisation, app functionality, and other purposes.

For advertising and marketing, WhatsApp only uses your device ID and advertising-related usage data.

Most of the data collected is used for analytics and app functionality, according to the list.

Data gathered for analytics includes: purchase history, coarse location, phone number, “other user content” (i.e. not messages, photos, videos, or audio data), user ID, device ID, product interaction usage data, advertising-related usage data, and various diagnostic data.

Telegram only uses the data it gathers for app functionality purposes, according to its App Privacy Labels.

Signal gathers no data that is used to personally identify you. While it uses your phone number, it is never linked to your identity.

The table below summarises the App Privacy Labels for WhatsApp, Telegram, and Signal. For the sake of simplicity, all data that is gathered to personally identify you is shown, regardless of how it is used.

Privacy Details
Data WhatsApp Telegram Signal
Identifiers Device ID
User ID
User ID No data linked to your identity
Contact info Phone number

Email address

Phone number

Name

Contacts Contacts Contacts
Usage data Advertising data
Product interaction
Purchases Purchase history
Location Coarse location
User content Other (not messages, photos, or audio data)
Diagnostics Crash data

Performance data

Other

Now read: Cool new features coming to WhatsApp

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