Ciphertext

Understanding Ciphertext in Cryptography

Ciphertext refers to the encrypted and encoded form of plaintext achieved by applying an algorithm known as a cipher.

Encryption results from encryption, rendering the original plaintext unreadable to unauthorized parties or entities lacking the proper cipher to decrypt it.

From Manual to Modern Encryption Techniques

A cipher, on its own, is an algorithm that can be applied to plaintext to produce ciphertext. It generates an unreadable output through an encryption process.

It is important to note that earlier cipher algorithms, which were performed manually, differ from modern algorithms that are executed using computers or machines.

Exploring Substitution and Transposition Ciphers

One type of cipher is a substitution cipher, where an alternative representation of plaintext is employed.

Another type is the polyalphabetic substitution cipher, which uses multiple mixed alphabets to encrypt plaintext. The change in mixed alphabets is indicated by an uppercase letter.

The transposition cipher, also known as a rail fence cipher, is another type of cipher that rearranges the positions of characters in the plaintext.

There is also the permutation cipher, where the positions of plaintext characters are shifted according to a specific pattern, resulting in a ciphertext that is a permutation of the original plaintext.

In public-key cryptography, two different keys, namely the private key and the public key, are used for the encryption and decryption processes.

The sender employs the recipient’s public key for encryption, while the recipient holds the private key, which remains unknown to others.