Fundamentals of Information Systems Security, 4th Edition

Symmetric and Asymmetric Key Cryptography

This section will present more information about the differences between symmetric and asymmetric key cryptography and their relative advantages and disadvantages.

Symmetric Key Ciphers

Symmetric key ciphers use the same key to encrypt plaintext into ciphertext and then to decrypt ciphertext back into plaintext, a fact that inherently represents a basic limitation for these cryptosystems. Because these ciphers require that both parties first exchange keys to be able to securely communicate, the parties must first be able to talk securely to exchange keys. This chicken-and-egg problem is what made cryptography difficult in the past for any large, dispersed organization, with the exception of governments, ...