CISSP Training Kit

What is cryptography?

Cryptography is defined as hiding the meaning of a message and the revelation of that meaning at some later time or other place. As security needs became more complex and cryptographic algorithms evolved into sophisticated cryptosystems, cryptography grew to provide more than just confidentiality services. Contemporary cryptosystems provide five major services:

• Confidentiality. Encryption provides confidentiality: keeping the secrets secret. Confidentiality can provide a form of access control or authorization. If a message is encrypted and the decryption key is only provided to those who are authorized to read the message, then those without the decryption cannot access the information within the message.

• Authentication. Cryptography ...