Who Owns Signal?

Signal's origins trace to 2010, when Moxie Marlinspike and Stuart Anderson founded Whisper Systems, a company developing encrypted communication tools for Android. Whisper Systems developed TextSecure, an encrypted SMS application, and RedPhone, an encrypted voice calling application. In November 2011, Twitter acquired Whisper Systems, primarily to hire Marlinspike. Following the acquisition, Marlinspike open-sourced the TextSecure and RedPhone code and left Twitter in 2013 to found Open Whisper Systems, a nonprofit software development organization dedicated to developing free, open-source cryptographic tools.

Open Whisper Systems released TextSecure 2.0 in February 2014, transitioning the app from encrypted SMS to an internet-based messaging protocol. This shift was significant because it allowed TextSecure to provide end-to-end encrypted messaging over data connections rather than relying on the SMS infrastructure, which is inherently insecure. The app was initially available for Android, with an iOS version following later in 2014.

In November 2015, Open Whisper Systems merged TextSecure and RedPhone into a single unified application called Signal, available for both Android and iOS. The consolidation simplified the user experience and established Signal as a comprehensive secure communication platform for messaging, voice calls, and video calls. The Signal Protocol, the cryptographic protocol underlying Signal's encryption, was simultaneously released as an open standard available for other developers to implement.

The Signal Protocol's adoption by major commercial messaging platforms was a landmark development in the history of encrypted communication. WhatsApp integrated the Signal Protocol in April 2016, bringing end-to-end encryption to approximately one billion users. Facebook Messenger added an optional Secret Conversations feature using the Signal Protocol in 2016. Google's Allo messaging app (later discontinued) also used the Signal Protocol. These adoptions validated the Signal Protocol as the gold standard for messaging encryption and established Marlinspike as one of the most influential cryptographers in the world.

In February 2018, Moxie Marlinspike and Brian Acton co-founded Signal Foundation to provide long-term organizational structure and sustainable funding for Signal's development. Acton, who had co-founded WhatsApp in 2009 and sold it to Facebook for approximately $19 billion in 2014, left Facebook in September 2017 over disagreements about Facebook's approach to user privacy and data monetization. His $50 million initial commitment to Signal Foundation provided the organization with financial stability to operate independently of commercial pressures.

Signal experienced a major surge in user growth in January 2021, when WhatsApp announced changes to its privacy policy that would allow greater data sharing with Facebook. The announcement triggered a mass migration of users to alternative messaging platforms, with Signal gaining millions of new users in a matter of days. The surge was amplified by a tweet from Elon Musk recommending Signal, which drove additional downloads. Signal's servers struggled to handle the volume of new registrations, resulting in temporary service disruptions.

Moxie Marlinspike stepped down as CEO of Signal Foundation in January 2022, citing a desire to allow new leadership to take the organization forward. Meredith Whittaker, a former Google employee and prominent AI ethics researcher who had co-founded the AI Now Institute at New York University, became Signal Foundation's President in 2022.

In early 2025, Signal became the subject of significant public attention when senior U.S. government officials, including members of the National Security Council, were found to have used Signal for communications about military operations. A journalist was accidentally added to a Signal group chat discussing planned military strikes, an incident that became known as "Signalgate." The incident demonstrated Signal's widespread adoption at the highest levels of government and generated substantial media coverage. Signal was named a TIME100 Company for 2025.