“Hash function is any function that can be used to map data of arbitrary size to fixed-size values.” (Wikipedia)
In my case, I store API Key hash in the database and verify the API Key by hasing the incomding token. I don’t need to know the original value of the API token, as I only verify it by hashing it and compare the hashed value to the one in the database.
In cryptography, a cipher is an algorithm for performing encryption or decryption. To do encryption and decryption, I used Symmetric key and AES algorithm. You need a key and a new IV to encrypt or decrypt the value.