Ciphertext

What Is Ciphertext?

In the world of cryptography, the ciphertext is a result of encryption that has been performed on plaintext through the usage of an algorithm, and this algorithm is known as a cipher.

Ciphertext is known as encrypted as well as encoded information due to the fact that it contains the original plaintext which is unreadable by an unauthorized party, or in other words, a person or a computer that does not have the proper cipher in order to decrypt it.

Decryption is the process of turning a ciphertext into a readable plaintext.

A cipher by itself is an algorithm that can be applied to plaintext in order to achieve ciphertext. It is the unreadable output of an encryption algorithm. 

Keep in mind that earlier cipher algorithms that were performed manually differ from the modern algorithms that are executed through the usage of a machine. 

One type of cipher is a substitution cipher, which offers an alternative to plaintext. Then there's a polyalphabetic substitution cipher, where a mixed alphabet is used to encrypt the plaintext, where at random points it will change to a different mixed alphabet that indicates the change with an uppercase letter.

Then there's the transposition cipher, which is known as a rail fence cipher and is a permutation of the plaintext.

There’s also a permutation cipher, where the positions which are held by the plaintext are shifted to a regular system so that the ciphertext constitutes a permutation of the plaintext itself.

In private-key cryptography, the attacker is aware of the plaintext and the corresponding ciphertext. The sender, as well as the receiver, has a pre-shared key, and this key is kept secret from anyone else. DES and AES are algorithms that are used in his type of encryption. 

In public-key cryptography, two different keys (the private key and the public key) are used for the encryption and the decryption process itself, where the sender uses the public key in order to perform the encryption and the receiver does not know the private key.