Java Security, 2nd Edition

Summary

Keys are a basic feature of any cryptographic system; they provide one of the inputs required to produce a digital signature (as well as other potential cryptographic operations). In this chapter, we looked at the basic classes that implement the notion of a key within the Java security package.

Keys are closely tied to the notion of certificates; a certificate contains a public key as well as an assurance from some known entity that the public key belongs to a specific entity. In a general sense, there are a great many things you can do with certificates, but for our purposes, we’re interested in certificates only from the perspective of the certificate’s user -- that is, we want to be able to import and verify a certificate, but we’re not too interested in creating our own certificates or in becoming a certificate authority.

Given that the operations we want to perform on keys and certificates are simple -- importing and exporting those certificates -- you’d expect that we could leave our discussion of keys for the time being. Unfortunately, the topic of finding a key for a particular entity (which is really just a case of importing a key) is a particularly troublesome topic, which we’ll examine in the next chapter.