Cryptography is the process of encrypting (scrambling) messages such that the messages can be stored and transmitted securely. This section introduces the basic terminology of cryptography and explains some of the common methods used.
Cryptography can be used to achieve secure communication, even when the transmission media (for example, the Internet) is untrustworthy. You can also use cryptography to encrypt your sensitive files, so that an intruder cannot understand them.
Cryptography can be used to ensure data integrity, as well as to maintain secrecy.
Using cryptography, it becomes possible to verify the origin of data and messages with digital signatures. For further details see Hashes and Digital Signatures.
When using cryptographic methods, only the session and private cryptographic keys must remain secret. The algorithms, the key sizes, and file formats can be made public without compromising security.