The process of converting ordinary plain text into unintelligible text and vice-versa. It’s used to store and transmit data in a certain form so intended to receive it can read and process it.

 Functions of cryptography

1. Privacy/confidentiality: Ensuring that no one can read the message except the intended receiver.
2. Authentication: The process of proving one’s identity.
3. Integrity: Assuring the receiver that the received message has not been altered in any way from the original.
4. Non-repudiation: A mechanism to prove that the sender really sent this message.
5. Key exchange: The method by which crypto keys are shared between sender and receiver.

For example,  we start with the unencrypted data, referred to as plaintext. Plaintext is encrypted into ciphertext, which will  be decrypted back into usable plaintext. The encryption and decryption is based upon the type of cryptography scheme being employed and some form of key. For those who like formulas, this process is sometimes written as:

Cryptography algorithm examples:

1. Symmetric Encryption. or Secret Key Cryptography: Uses a single key for both encryption and decryption; also called symmetric encryption. Primarily used for privacy and confidentiality.
2. Asymmetric Encryption or Public Key Cryptography: Uses one key for encryption and another for decryption. 
3. Hash Functions: A hash value with fixed length is calculated as per the plain text which makes it impossible for contents of plain text to be recovered. Many operating systems use hash functions to encrypt passwords. No key usage for this algorithm.

In relation to cybersecurity, any sensitive information should be encrypted due to potential cyber criminals and hackers. Wireless devices are simpler for cyber criminals to access than wired hardware. Because so much information is now transmitted over wireless networks, encryption becomes more important.

Here are some video links about Cryptography: