GSMK CryptoPhone for Windows is a free software application for desktop or notebook computers running the Microsoft Windows® operating system. It uses the same 4096-bit Diffie-Hellman key exchange and 256-bit AES and Twofish symmetric encryption as all other GSMK CryptoPhone products, thus permitting not only secure computer-to-computer telephone calls, but also encrypted calls to GSMK CryptoPhone secure mobile and satellite phones.

CryptoPhone for Windows is a free software-only encryption application and thus offers no protection against targeted attacks against the computer itself.