Signal

Signal for Desktop is a Windows variant of the Signal mobile app, a chat and phone tool (including video calls) that transmits all communications encrypted and therefore completely secure. In addition to regular communication, files, photos and videos can also be transferred, and these are encrypted as well. The encryption key is known only to the sending and receiving applications, so its contents cannot be eavesdropped on. The identifier for using the Signal service is a phone number, which is needed to register for the service on a mobile phone, then you can log in to this desktop version via a QR code.