What is Secret Key Cryptography (Symmetric Key)

Secret key cryptography is the type of encryption that is familiar to most people. In this type of cryptography, the sender and receiver both know a secret key. The sender encrypts the plaintext message with the secret key, and the receiver decrypts the message with the same secret key. Obviously, the challenge is to make the secret key available to both the sender and receiver without compromising it. For increased security, the secret key should be changed at frequent intervals. Ideally, a particular secret key should only be used once.