The Role of Cryptography in Information Security
Cryptography can be used to achieve several goals of information security, including confidentiality, integrity, and authentication.
Confidentiality: First, cryptography protects the confidentiality (or secrecy) of information. Even when the transmission or storage medium has been compromised, the encrypted information is practically useless to unauthorized persons without the proper keys for decryption.
Integrity: Cryptography can also be used to ensure the integrity (or accuracy) of information through the use of hashing algorithms and message digests.
Authentication: Finally, cryptography can be used for authentication (and non-repudiation) services through digital signatures, digital certificates, or a Public Key Infrastructure (PKI).