A discussion of various methods of protecting information and other valuable resources, and the variousmethods utilized to bypass the security mechanisms. Everything from early locks and fortress walls to modern daycryptographic algorithms.Please support by purchasing my books from https://www.lulu.com/spotlight/n9mtk OR for Kindle from via direct donation from https://paypal.me/n9mtk, or via one of many crowdsourcing sites: https://www.patreon.com/n9mtk, https://www.makersupport.com/n9mtk, OR https://www.hatreon.net/n9mtk.