Overview
Cryptography is one of the most complex issues faced by security practitioners. It is not a topic you can explain in passing; we spend a full day on it. You do not need a calculator for this day since we do not delve into the math behind crypto. We introduce you to cryptographic terms. We explain what steganography is. We then look at historical examples of cryptography. We do this because even the most advanced cryptographic systems today utilize methods of encrypting data that were used hundreds of years B.C. So we explain the historical examples that are very easy to understand to make it easier to understand modern cryptographic methods and principles.
We cover the "work factor" - the length of time necessary to break cryptography and why understanding this concept is so important. We cover some of the potential attacks against crypto and which ones are viable against modern cryptography and which attacks are nonviable. We cover hashing, symmetric & asymmetric cryptography and how each works. We then show real-world examples of how those cryptographic systems work. We cover the secure key exchange mechanism called Diffie-Hellman. We even briefly cover digital certificates and Public Key Infrastructure (PKI).
Once we have thoroughly explained how cryptography works, we end the day with a discussion of data encrypting protocols. Things that use cryptography to secure data on our networks and across the Internet. Here we cover email encryption, secure remote administration, secure file transfer, and three examples of Virtual Private Networks (VPNs).
Again, we do not spend our time on the mathematics behind cryptography, but instead, we are highly process focused. We explain the steps required to make crypto work, the order those steps must occur in, and which key you must use for each step.
Exercises
Lab - Crypto by Hand: Apply the knowledge and skills you've learned to encrypt information using mono and poly alphabetic ciphers and gain a better understanding of triple encryption (as used by Triple DES).
Lab - Visual Crypto: Observe the encryption process that occurs by turning plaintext (what you can read) into ciphertext (what you cannot read) in real-time. Increase your understanding of what "randomness in ciphertext" truly means. See ciphertext turned back into plaintext. Find out what happens if you edit cyphertext and try to decrypt it. Learn what happens if you attempt to decrypt data with the wrong key. The lab provides visual proof of many definitive statements made by the instructor throughout the lecture.