Machine generated contents note: pt. I Setting the Scene 1.Basic Principles 1.1.Why Information security? 1.2.Security risks 1.3.Security services 1.4.Fundamentals of cryptosystems 1.5.Cryptosystem security assumptions 1.6.Breaking cryptosystems 1.7.Summary 1.8.Further reading 1.9.Activities 2.Historical Cryptosystems 2.1.Monoalphabetic ciphers 2.2.Historical advanceā¦