Real-Time Communication

Discover secure and private ways to communicate with others online without letting any third parties read your messages.

Encrypted Instant Messenger

We only recommend instant messenger programs or apps that support end-to-end encryption (E2EE). When E2EE is used, all transmissions (messages, voice, video, etc.) are encrypted before they are sent from your device. E2EE protects both the authenticity and confidentiality of the transmission as they pass through any part of the network (servers, etc.).

All the client programs/apps we chose are free and open-source software unless otherwise mentioned. This to ensure that the code can be independently verified by experts now and in the future.

We have described the three main types of messaging programs that exist: Centralized, Federated and Peer-to-Peer (P2P), with the advantages and disadvantages of each.

Centralized

Centralized messengers are those where every participant is on the same server or network of servers controlled by the same organization.

Advantages

  • New features and changes can be implemented more quickly.
  • Easier to get started with and to find contacts.

Disadvantages

Signal

Signal Signal is a mobile app developed by Signal Messenger LLC. The app provides instant messaging, as well as voice and video calling. All communications are E2EE unless you choose to send as SMS. Its protocol has also been indepedently audited (PDF) Requires phone number VoIP


Keybase

Keybase Keybase provides a hosted team chat with E2EE. Its protocol has also been indepedently audited (PDF). Keybase can help you prove you own social media accounts though the use of cryptographic signing of "identity proofs". Warning


Federated

Federated messengers use multiple, independent servers that are able to talk to each other (email is one example of a federated service). Federation allows system administrators to control their own server and still be a part of the larger communications network.

Advantages

  • Allows for greater control over your own data when running your own server.
  • Allows you to choose who to trust your data with by choosing between multiple "public" servers.
  • Often allows for third party clients which can provide a more native, customized, or accessible experience.
  • Generally a less juicy target for governments wanting backdoor access to everything as the trust is decentralized. The server may be hosted independently from the organization developing the software.
  • Server software can be verified that it matches public source code, assuming you have access to the server or you trust the person who does (eg family member)
  • Third-party developers can contribute code and add new features, instead of waiting for a private development team to do so.

Disadvantages

  • Adding new features is more complex, because these features need to be standardized and tested to ensure they work with all servers on the network.
  • Some metadata may be available. Information like "who is talking to whom," but not actual message content if E2EE is used.
  • Federated servers generally require trusting your server's administrator. They may be a hobbyist or otherwise not a "security professional," and may not serve standard documents like a privacy policy or terms of service detailing how your data is utilized.
  • Server administrators sometimes choose to block other servers, which are a source of unmoderated abuse or break general rules of accepted behavior. This will hinder your ability to communicate with users on those servers.

Matrix

Matrix Matrix is an open-source project that publishes the Matrix open standard for secure, decentralized, real-time communication.
Riot.im is the popular reference client produced by the Matrix.org team. It offers optional E2EE for 1:1 and group conversations that must be turned on by the user. (This can be done by clicking on the toggle switch which is accessed by clicking the room name or user name of the chat → Security & Privacy → Encrypted). In the future it will be on by default.


Worth Mentioning

  • Other Matrix clients, that may however be less feature complete than Riot.im.
  • XMPP (Extensible Messaging and Presence Protocol) is an open-source communications protocol that began development in 1999. Since then, XMPP has been extended by the publishing of XEPs (XMPP Extension Protocols). OMEMO is the most popular XEP (XMPP extension) for E2EE. Unlike Matrix, clients are only developed by the community and not by the foundation itself. Warning
  • Kontalk is a community-driven instant messaging network based on XMPP.

Peer to Peer (P2P)

Peer-to-Peer instant messengers connect directly to each other without requiring third-party servers. Clients (peers) usually find each other through the use of a distributed computing network. Examples of this include DHT (distributed hash table) (used with technologies like torrents and IPFS, for example), or Ethereum's Whisper protocol (used with some newer DApps). Another approach is proximity based networks, where a connection is established over WiFi or Bluetooth (for example, Briar or the Scuttlebutt social networking protocol). Once a peer has found a route to its contact via any of these methods, a direct connection between them is made.

Advantages

  • Minimal information is exposed to third parties.
  • Modern P2P platforms implement end-to-end encryption by default. There are no servers that could potentially intercept and decrypt your transmissions, unlike centralized and federated models.

Disadvantages

  • Reduced feature set:
    • Messages can only be sent when both peers are online, however, your client may store messages locally to wait for the contact to return online.
    • Generally increases battery usage on mobile devices, because the client must stay connected to the distributed network to learn about who is online.
  • Your IP address and that of the contacts you're communicating with may be visible if you do not use the software in conjunction with a self contained network, such as Tor or I2P. Many countries have some form of mass surveillance and/or metadata retention.

Briar

Briar Encrypted instant messenger that connects to contacts via Wi-Fi, Bluetooth, or Tor over the internet to synchronize messages. Technology such as this has proven to be useful when Internet availability is an issue, such as in times of crisis.


Jami

Jami Encrypted instant messaging and video calling software. Uses TLS 1.3 for encryption. VoIP


qTox

qTox Encrypted instant messaging and video calling software. Uses its own encryption protocol that has not yet been officially audited by cryptographers. Experimental VoIP


Worth Mentioning

Recent news about breaking E2EE on centralized instant messengers

November 2019
October 2019
August 2019
July 2019
May 2019
January 2019
December 2018

Complete Comparison

Independent security audits


Video/Voice Calling

Linphone

Linphone Linphone is an open-source SIP Phone and a free voice over IP service, available on mobile and desktop environments and on web browsers. It supports ZRTP for end-to-end encrypted voice and video communication.


Mumble

Mumble Mumble is an open-source, low-latency, and high quality voice chat application primarily intended for use while gaming. Note that while Mumble doesn't log messages or record by default, it's missing end-to-end encryption, so self-hosting is recommended.


Worth Mentioning

Related Information


Team Chat Platforms

Matrix

Matrix Matrix is an open-source project that publishes the Matrix open standard for secure, decentralized, real-time communication.
Riot.im is the popular reference client produced by the Matrix.org team. It offers optional E2EE for 1:1 and group conversations that must be turned on by the user. (This can be done by clicking on the toggle switch which is accessed by clicking the room name or user name of the chat → Security & Privacy → Encrypted). In the future it will be on by default.


Rocket.chat

Rocket.chat Rocket.chat is an self-hostable open source platform for team communication. It has optional federation and experimental E2EE. Experimental E2EE


Keybase

Keybase Keybase provides a hosted team chat with E2EE. Its protocol has also been indepedently audited (PDF). Keybase can help you prove you own social media accounts though the use of cryptographic signing of "identity proofs". Warning