Understanding the Term
In the science of secure communication techniques, cryptography, a cipher is a tool used for information exchange without a third party being able to interfere or breach privacy. It follows a set of uniquely defined instructions that a system can follow in order to decrypt or encrypt a message or data.
The encrypted text that is unreadable without authorized access is called Ciphertext. By means of an encryption algorithm, Plaintext is transformed into ciphertext. This entire process is facilitated by the involvement of a particular piece of secret information, called a cryptographic key.
To achieve this process of turning clear information into unreadable or inaccessible data, and vice versa, cipher algorithms involve the use of a particular piece of secret information, called a cryptographic key.
Only those who are authorized to access the data should be able to decrypt the ciphertext back into readable plaintext.