Cryptography is the branch of mathematics that deals with encoding messages to prevent them from being read by anyone except their intended recipient. In ancient times, it was used primarily as a means for securely exchanging messages in wartime.
Nowadays, cryptography is used for everything from ensuring privacy on Facebook to encrypting sensitive data at corporations such as Google and Apple.
There are many different types of cryptographic algorithms – some use complex math problems, and others use long strings of text called keys.
The application requirements will determine the algorithm (e.g., if what needs protection is small amounts of data like credit card numbers or passwords, then an algorithm with simple math would suffice).
Cryptography converts information from its original form into messages or data, called “ciphertext.” To become readable, the data must be decoded by various, often complex rules. The person who performs this process is called a cryptographer. The message itself is referred to as plaintext or cleartext.
The fundamental purposes of using cryptography are to protect electronic data during transmission across an insecure channel by converting it from a comprehensible format into an unreadable format so that only those intended for receipt can convert it back to its initial state.