The Official (ISC)2 SSCP CBK Reference, 5th Edition

CHAPTER 5Cryptography

Cryptography is the art and science of “secret writing” and has been used for thousands of years to provide its users with some degree of protection for their messages, documents, and other information. Today, it is the backbone of our e-business e-society—without pervasive, nonstop use of cryptography as an infrastructure, online banking, international business, personal communications, defense, and national security would be far more difficult (and far less profitable!) to conduct. Cryptography provides powerful ways to prove that a document or a file is what it claims to be and keep it secret and safe. It authenticates people and organizations as well. The transparency, reliability, and integrity of information are ...