Secret Key Cryptography

16 Three pass protocol

This chapter covers

• Three pass protocol based on exponentiation
• Three pass protocol based on matrix multiplication
• Three pass protocol based on 2-sided matrix multiplication

Sections 2.2 and 2.3 describe how modern cryptography is divided into 3 branches, Secret Key, Public Key and Personal Key. Up to this point, this book has described only methods for Secret Key cryptography. Public Key cryptography is described in many books, so it will not be covered here. This chapter will discuss Personal Key cryptography, the lesser-known third branch of cryptography. Personal Key cryptography is sometimes called keyless cryptography, since the parties do not need to transmit or share any keys.

The basic concept of Personal Key ...