CIPHERTEXT

GROUP MEMBERSM. USMAN AHMED

HUMZA KHAN MUBEEN

CIPHERTEXT

In cryptography, ciphertext is the result of encryption performed on plaintext using an algorithm, called a cipher.

HISTORICAL PERSPECTIVE

Cryptography began thousands of years ago.

Early 20th century, the invention of complex mechanical and electromechanical machines.

CONTRIBUTION OF MUSLIMS

Throughout history, the need for secrecy has been important.Abu Yusuf Ya’qub ibn e Ishaaq Al-Kindi was the first to De-Cipher an encrypted message.

TYPES OF CIPHERSHistorical pen and paper ciphers used in the past are

sometimes known as classical ciphers. They include:Substitution cipher: the units of plaintext are replaced

with ciphertext (Caesar cipher)Transposition cipher: the ciphertext is

a permutation of the plaintext (Rail fence cipher)Polyalphabetic substitution cipher: a substitution

cipher using multiple substitution alphabets (Vigenère cipher and Enigma machine)

Permutation cipher: a transposition cipher in which the key is a permutation

Private-key cryptography (symmetric key algorithm): the same key is used for encryption and decryption

Public-key cryptography (asymmetric key algorithm): two different keys are used for encryption and decryption