Computer Security Literacy

Appendix B: Basics of Cryptography

B.1    INTRODUCTION

Cryptography is one of the most heavily relied-on security mechanisms to preserve confidentiality of information at rest (i.e., data stored on a computer hard drive) and in transit (i.e., data traveling over the Internet). Without cryptography, the Internet would be a drastically different place than we have come to know and depend on in our daily lives. The average user of information technology, whether or not aware of it, relies on cryptography virtually every day of his or her life (i.e., via HTTPS [Hypertext Transfer Protocol Secure], secure wireless networks, password hashes). This appendix describes cryptography’s underpinnings and explores classic cryptographic algorithms, principles, ...