Some form of cryptography can be found nearly everywhere in computer technology. Popular standalone programs, like PGP and GPG, aid in securing communications. Web browsers and other network client programs implement cryptographic layers in their channels. Drivers and programs exist to secure files on disk and control access thereto. Some commercial programs use cryptographic mechanisms to limit where they can be installed and how they can be used. Basically, every time you find a need to control the access and usage of computer programs or digital data, cryptographic algorithms are important elements in the protocol for use of these programs or data.