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The 4 Best End-to-End Encryption Tools for Voice Chat

by Emily Iwankovitsch Social Media Marketing Manager

As our lives move increasingly online, encryption keeps our personal data private and secure — sometimes without us even being aware of it. And now that real-time voice communication is happening more and more in web and native apps, it’s important to think about how to ensure a conversation is truly private.

End-to-end encryption is widely used by many apps today, and is becoming the industry standard. It behaves like a lock and key, where just you and the people in the chat or call have access to the conversation. “End-to-end encryption is the act of applying encryption to the data on your device and not decrypting it until it reaches the destination. Even the service that is sending the data can't see the content of your message when it passes through the server.” Currently, this method is the safest way to communicate online. “This is different from encryption-in-transit, when messages may be decrypted at the server before going to a final destination.”

What are some examples of apps you can make calls on or send and receive messages that use end-to-end encryption? 

There are more, but let’s focus today specifically on the apps that have audio capabilities in addition to text messaging. How do they work? What encryption protocols do they use? 

The 4 Best End-to-End Encryption (E2EE) Tools for Real-time Voice Communication

First, to highlight why end-to-end encryption matters, we’ll quote the CEO of Wickr, Joel Wallenstrom: “When you give multiple third parties access to your company's data, you increase the risk of your data being stolen or used in ways that don't benefit you, or your organization. We have come to an inflection point where there may be too much risk and too little reward for giving large tech services access to all your data.”

He continues, “Encryption is the key to taking back some data control from technology processes that gain access to individual and corporate information just because they can. This makes encryption the real solution to the problem – and keeps your data out of the prying eyes (and ears!) of tech companies and cybercriminals alike. Encryption is one of the most transformative and vital technologies available today.”

1. Signal Protocol

“The Signal protocol (formerly known as the TextSecure Protocol) is a non-federated cryptographic protocol that can be used to provide end-to-end encryption for voice calls and instant messaging conversations.” The protocol was developed by Open Whisper Systems in 2013 and was first introduced in the open-source TextSecure app, which later became Signal

Tom’s Guide writes about Signal: “For starters, all Signal messages are encrypted end-to-end by default. Signal's open-source encryption protocol is available for all to see and anyone to examine, meaning that flaws can be found and fixed quickly.”

The Signal protocol is well on its way to accounting for a majority of the world's real-time text conversations. Andy Greenberg writes for WIRED in November 2020, “WhatsApp first adopted the Signal protocol in 2014 to end-to-end encrypt all messages between Android phones, in what [creator] Marlinspike told WIRED was ‘the largest deployment of end-to-end encryption ever.’ WhatsApp switched it on by default for all billion-plus users two years later. Shortly thereafter, Google rolled out end-to-end encryption via the Signal protocol as an opt-in feature for its now-defunct Allo messenger and in its Duo video chat service. Facebook followed by adding it as an opt-in "Secret Conversations" feature in Facebook Messenger a few months later. Google's decision to integrate the Signal protocol into Android's messaging app by default represents the biggest new collection of phones to adopt the standard in years, with hundreds of millions more devices.”

Greenberg continues: “Why have the tech giants of the world all chosen Signal as their go-to crypto protocol? Its standout feature, says Johns Hopkins computer science professor and cryptographer Matthew Green, is how it implements what's known as “perfect forward secrecy.’” You can read more about that here.

WhatsApp also provides a technical white paper with an encryption overview here, or here is its general FAQ.

Facebook Messenger provides more information about its encryption here.

You can read about how your calls on Google’s Duo stay private with end-to-end encryption here, and here’s the technical white paper.

2. Telegram’s MTProto 2.0 Protocol

Check out Telegram’s FAQ to learn more about its end-to-end encrypted voice and video calls that use the MTProto 2.0 protocol.

Tom’s Guide writes: “An academic research paper published in December 2020 analyzed Telegram's MTProto 2.0 protocol and deemed it fundamentally sound. It added that further investigation was needed in order to deem this protocol suite definitely secure, however. Many information-security experts state that Telegram's ‘homegrown encryption technology’ has a limited track record compared to Signal's, although the consensus seems to be that it is more secure than MTProto 1.0.”

Since we’re delving specifically into the audio component of apps offering end-to-end encryption, it’s worth mentioning that earlier this year, Telegram launched a social audio platform called Voice Chats 2.0. “The new feature allows for live voice chats in Telegram Channels for unlimited participants. The result is much like Clubhouse or Twitter Spaces albeit with some twists unique to Telegram. As the social audio market explodes, Telegram clearly sees a chance to compete against Clubhouse, which passed 10 million weekly active users in late February. The unique Telegram features and its reputation as a secure messaging service are likely to entice many to at least try hosting voice chats on the platform,” writes Eric Hal Schwartz for Voicebot.ai.

3. Viber’s Protocol

Viber’s protocol uses the same concepts of the “double ratchet” protocol used in Open Whisper Systems Signal application, however, Viber’s implementation was developed from scratch and does not share Signal’s source code.” Read the technical overview here; page 4 specifically discusses encrypted calls.

“Users can send voice and text messages, photos and videos to groups of any size using Viber. It also offers fully encrypted voice and video chats on mobile devices and major desktop operating systems. The company has stepped up its game when it comes to their end-to-end encryption as it used to be that only one-on-one communications were protected, but now group chats are also secured by E2EE.”

You can check out its general page on security here.

4. Wickr Secure Messaging Protocol

The Wickr Secure Messaging Protocol is the foundation for Wickr security, and supports “end-to-end encryption for file transfer, audio/video communications, or future use cases,” Wickr shares in its technical white paper.

Here’s an overview: “Wickr is one of the only secure messaging apps that can truly be used anonymously. This application allows users to communicate with others either one-to-one or in groups with fully encrypted text messages, voice messages and memos. Wickr can be a collaboration tool instead of just a messaging app as there is the ability to share screens, locations, and online statuses. Wickr does not require an email address or phone number upon registration, ensuring that user data is not collected and therefore, the app does not have access to it. Encryption is turned on by default, and transparency reports are available to anyone who uses Wickr. This application uses Perfect Forward Secrecy (PFS) and supports Two-Factor Authentication (2FA). Wickr does not log IP Addresses or other metadata.”

End-to-End Encryption with Spatial Audio

Since we have specifically discussed the audio component of these apps that offer end-to-end encryption, it’s worth noting that it’s now possible to enjoy group calls and social audio components in spatial audio while everything (of course) remains encrypted.


High Fidelity’s Local Spatializer actually mixes audio in real-time on the client only — so it works with any streaming service that offers end-to-end encryption.

It’s a self-contained C++ codebase (no third-party dependencies or libraries) that is designed to be independent of your native application’s user interface.

Why does using spatial audio matter so much for group calls and social audio? You might immediately think it’s to increase immersion, which is great… but it goes far beyond that. Clubhouse, for instance, recently integrated the Local Spatializer. As their Head of Streaming, Justin Uberti, explained in his interview with TechCrunch, “Your mind has to figure out who’s talking. Without spatial cues you have to use timbre… that requires more cognitive effort. [Spatial audio] could actually make for a more enjoyable experience aside from more immersion.”

Curious to learn more about how spatial audio decreases cognitive load while improving speech intelligibility? Check out the in-depth research.

Have questions about how the Local Spatializer might work with your end-to-end encrypted app? Get in touch with us.

Published by Emily Iwankovitsch November 11, 2021

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