For example, the Widget Works company might have an opportunity to provide super widgets for a large trade show and wants to submit a bid over the public network. Widget Works also wants to hide this information from any rivals. The company decides to use encryption. Figure 32 shows what happens. The Purveyor Encrypt WebServer provides extended access control to files and directories on the server.
Authentication takes place by using agreed-upon keys to generate and verify the message digest.
The message digest consists of summary information that is transmitted with the message and is uniquely derived from the message contents. Using a digital signature is one method of authentication. A digital signature is a unique group of random pieces of data. A digital signature serves as a signature for an electronic message in the same way that a handwritten signature serves as a signature for a printed message. Verify the authenticity of a digital signature that has been applied to a message.