Shortly after the acquisition, Whisper Systems' RedPhone service was made unavailable. Marlinspike could help the then-startup improve its security'. The acquisition was done 'primarily so that Mr. The financial terms of the deal were not disclosed by either company. In November 2011, Whisper Systems announced that it had been acquired by Twitter. They also developed a firewall and tools for encrypting other forms of data. Among these were an encrypted texting program called TextSecure and an encrypted voice calling app called RedPhone. The company produced proprietary enterprise mobile security software. Security researcher Moxie Marlinspike and roboticist Stuart Anderson co-founded a startup company called Whisper Systems in 2010. Today, the Signal app is developed by Signal Messenger LLC, which is funded by the Signal Technology Foundation. In 2018, Signal Messenger was incorporated as an LLC by Moxie Marlinspike and Brian Acton and then rolled under the independent 501c3 non-profit Signal Technology Foundation. The group picked up the open source development of TextSecure and RedPhone, and was later responsible for starting the development of the Signal Protocol and the Signal messaging app. Open Whisper Systems (abbreviated OWS ) was a software development group that was founded by Moxie Marlinspike in 2013.
