Cryptography, An Introduction : Third EditionThe third edition is now online. You may make copies and distribute the copies of the book as you see fit, as long as it is clearly marked as having been authored by N.P. Smart.We give a numbering system to present versions.The first number presents the edition numberThe second number represents a correction which is major, i.e. something absolutely crucial has been corrected.The third number represents a minor change, e.g. small addition etc.The fourth number represents a very minor correction (spelling etc).The current number is 3.0.1.3