Security in Computing, Third Edition

2.7. Public Key Encryption

So far, we have looked at encryption algorithms from the point of view of making the scrambling easy to do (so that the sender can easily encrypt a message) and the decryption easy for the receiver but not for an intruder. But this functional view of transforming plaintext to ciphertext is only part of the picture. We can also examine the role of keys in encryption. We have noted how useful keys can be in deterring an intruder, but we have assumed that the key must remain secret for it to be effective. In this section, we look at ways to allow the key to be public but still protect the message. We also focus on the RSA algorithm, a public key system that is a popular commercial-grade encryption technique.

In 1976, Diffie ...