Signal is the world’s most widely used truly private messaging app, and our cryptographic technologies provide extra layers of privacy beyond the Signal app itself. Since launching in 2013, the Signal Protocol—our end-to-end encryption technology—has become the de facto standard for private communication, protecting the contents of billions of conversations in WhatsApp, Google Messages, and many others. Signal also continues to invest in research and development in the pursuit of extending communications privacy. This commitment underlies our recent work to add a layer of quantum resistance to the Signal Protocol, and our previous work on metadata protection technologies that help keep personal details like your contact list, group membership, profile name, and other intimate information secure. This singular focus on preserving the ability to communicate privately is one reason that we work in the open, documenting our thinking and making our code open source and open to scrutiny—so you don’t have to take our word for it.