We discussed the general principles of computer security earlier. Here we will look at how secure communication is built into Apache. But before we do that, we have to look at the legal problems, which are somewhat trickier than the technical ones. This is perhaps not surprising, when one thinks about the social power that effective encryption gives the user.
Obviously, browser and server have to be thinking along the same lines if they are going to collaborate on tricky enterprises like PK encryption and decryption. In this case it is Netscape who calls the tune, with their Secure Sockets Layer (SSL) protocol, which uses the PK algorithm.[**]
[**] There is a rival scheme called Secure Hypertext Transfer Protocol (SHTTP) that is not widely used. If it is ever adopted by the Internet Engineering Task Force (IETF), who decide what is and isn't an Internet protocol, SSL will be called Transport Layer Security (TLS).
There are two areas of legal concern in making use of PK: patent rights and national security.
The patent position is this:
The Massachusetts Institute of Technology and the Board of Trustrees of the Leland Stanford Junior University have granted Public Key Partners (PKP) exclusive sublicensing rights to the following patents issued in the United States, and all of their corresponding foreign patents: Cryptographic Apparatus and Method ("Diffie-Hellman") No. 4,200,770 Public Key Cryptographic Apparatus and Method ("Hellman-Merkle") ...