TextSecure was an encrypted messaging application for
Android that was developed from 2010 to 2015. It was a predecessor to
Signal
In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The ''IEEE Transactions on Signal Processing'' ...
and the first application to use the
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 W ...
, which has since been implemented into
WhatsApp
WhatsApp (also called WhatsApp Messenger) is an internationally available freeware, cross-platform, centralized instant messaging (IM) and voice-over-IP (VoIP) service owned by American company Meta Platforms (formerly Facebook). It allows us ...
and other applications. TextSecure used
end-to-end encryption
End-to-end encryption (E2EE) is a system of communication where only the communicating users can read the messages. In principle, it prevents potential eavesdroppers – including telecom providers, Internet providers, malicious actors, and even ...
to secure the transmission of text messages, group messages, attachments and media messages to other TextSecure users.
TextSecure was first developed by
Whisper Systems
Whisper Systems was an American enterprise mobile security company that was co-founded by security researcher Moxie Marlinspike and roboticist Stuart Anderson in 2010. The company was acquired by Twitter in November 2011. Some of the company's s ...
, who were later
acqui-hired by
Twitter
Twitter is an online social media and social networking service owned and operated by American company Twitter, Inc., on which users post and interact with 280-character-long messages known as "tweets". Registered users can post, like, and ...
. The application's
source code
In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the wo ...
was then released under a
free and open-source software
Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...
license. In 2013, TextSecure's development was picked up by an independent group called
Open Whisper Systems
Open Whisper Systems (abbreviated OWS) was a software development group that was founded by Moxie Marlinspike in 2013. The group picked up the open source development of TextSecure and RedPhone, and was later responsible for starting the devel ...
, who merged it with an encrypted voice calling application called RedPhone and renamed the product as Signal.
History
Whisper Systems and Twitter (2010–2011)
TextSecure started as an application for sending and receiving encrypted SMS messages.
Its
beta version
A software release life cycle is the sum of the stages of development and maturity for a piece of computer software ranging from its initial development to its eventual release, and including updated versions of the released version to help impro ...
was first launched on May 25, 2010, by
Whisper Systems
Whisper Systems was an American enterprise mobile security company that was co-founded by security researcher Moxie Marlinspike and roboticist Stuart Anderson in 2010. The company was acquired by Twitter in November 2011. Some of the company's s ...
,
a startup company co-founded by security researcher
Moxie Marlinspike
Moxie Marlinspike is an American entrepreneur, cryptographer, and computer security researcher. Marlinspike is the creator of Signal, co-founder of the Signal Technology Foundation, and served as the first CEO of Signal Messenger LLC. He is als ...
and roboticist Stuart Anderson.
In addition to launching TextSecure, Whisper Systems produced a firewall, tools for encrypting other forms of data, and
RedPhone
Open Whisper Systems (abbreviated OWS) was a software development group that was founded by Moxie Marlinspike in 2013. The group picked up the open source development of TextSecure and RedPhone, and was later responsible for starting the devel ...
, an application that provided encrypted voice calls.
All of these were