End-to-end encryption

WhatsApp Messenger, commonly known simply as WhatsApp, is an American social media, instant messaging (IM), and Voice over IP (VoIP) service accessible via desktop and mobile app. Owned by Meta Platforms, the service allows users to send text messages, voice messages, and video messages, make voice and video calls, and share images, documents, user locations, and other content. The service requires a cellular mobile telephone number to register. WhatsApp was launched in May 2009. In January 2018, WhatsApp released a standalone business app called WhatsApp Business which can communicate with th

Telegram is a cloud-based, cross-platform social media and instant messaging (IM) service. It launched for iOS on 14 August 2013 and Android on 20 October 2013. It allows users to exchange messages, share media and files, and hold private and group voice or video calls as well as public livestreams. It is available for Android, iOS, Windows, macOS, Linux, and web browsers. Telegram offers end-to-end encryption in voice and video calls, and optionally in private chats if both participants use a mobile device.

instant messaging app developed by Meta Platforms

privacy-focused encrypted messaging app

video-conferencing software

end-to-end encrypted e-mail service from Proton AG

cryptographic paradigm involving uninterrupted protection of data traveling between two communicating parties

networking protocol for real-time communication and data synchronization

iMessage is an instant messaging service which was developed by Apple and launched on October 12, 2011. iMessage functions exclusively on Apple platforms – including iOS, iPadOS, macOS, watchOS, and visionOS. iMessage uses the Messages app client.

communication protocol for mobile phones, aiming at replacing SMS and MMS messages with a system that is richer, provides phonebook polling (for service discovery), and transmit in-call multimedia via mobile data

EncroChat was a Europe-based communications network and service provider that offered modified smartphones allowing encrypted communication among subscribers. It was used primarily by organised crime members to plan criminal activities.

non-federated cryptographic protocol

instant messaging client

Cryptocat is a discontinued open-source desktop application intended to allow encrypted online chatting available for Windows, OS X, and Linux. It uses end-to-end encryption to secure all communications to other Cryptocat users. Users are given the option of independently verifying their buddies' device lists and are notified when a buddy's device list is modified and all updates are verified through the built-in update downloader.

thumb|Logo of OMEMO OMEMO is an extension to the Extensible Messaging and Presence Protocol (XMPP) for multi-client end-to-end encryption developed by Andreas Straub. According to Straub, OMEMO uses the Double Ratchet Algorithm "to provide multi-end to multi-end encryption, allowing messages to be synchronized securely across multiple clients, even if some of them are offline". The name "OMEMO" is a recursive acronym for "OMEMO Multi-End Message and Object Encryption". It is an open standard based on the Double Ratchet Algorithm and the Personal Eventing Protocol (PEP, XEP-0163). OMEMO offers

cryptographic key management algorithm

Arattai Messenger (or simply Arattai) is an encrypted messaging service for instant messaging, voice calls, and video calls, developed by Zoho Corporation. The name Arattai means "chat" or "conversation" in Tamil. The app was soft-launched in January 2021. The app saw a sharp surge in downloads in September 2025, partially fueled by endorsements from Indian government officials. However, the app dropped from the top rankings in October 2025.

privacy preserving communication app

encrypted instant messenger app (IM)

organization dedicated to creating email with end-to-end encryption