Encryption Techniques Assignment 2022

Running head: ENCRYPTION TECHNIQUES
ENCRYPTION TECHNIQUES
Cryptography
Cheng-Jing Kuo
Name of the Student:
Name of the University:
Author Note:

ENCRYPTION TECHNIQUES1
Table of Contents
Introduction................................................................................................................................2
Discussion..................................................................................................................................2
Public Key and Secret Key Cryptography.............................................................................2
Substitution Ciphers and Transposition Ciphers....................................................................2
Substitution Techniques.....................................................................................................3
Transposition Techniques..................................................................................................3
Stream Cipher and Block Cipher...........................................................................................3
Block Cipher......................................................................................................................3
Stream Cipher.....................................................................................................................5
Shift Register..................................................................................................................5
Feedback Function.........................................................................................................5
Hybrid Algorithms, PGP........................................................................................................5
Conclusion..................................................................................................................................6
References..................................................................................................................................7

ENCRYPTION TECHNIQUES2
Introduction
For several centuries, cryptography was one type of secret technology which was used
in the black chambers by few governments. Two major ideas used for encryptions are
cryptography of public key and secret key. Cryptography is mathematical technique’s study
which is related with factors of information security like data integrity, data authentication,
confidentiality and entity authentication [5]. Cipher is method used for encrypting data.
Plaintext is original data that is encrypted and encryption output’s data is termed as
cryptogram or ciphertext. Cipher can be attacked by two ways: statistics attack and
exhaustive attack. There exists three major purposes of cryptography. First, creation of
confidentiality. Second, providing authentication that is used for recognizing if message
provider is authorized or not. And third is data integrity. Kerckhoff Principle is used for
modern cryptography [9]. It should be assumed that attackers know every details about
cipher, exact algorithm used and it’s every inner workings, but one small part of data known
as key.
Discussion
Public Key and Secret Key Cryptography
The major idea of how method of data encryption takes place is discussed in this
section. Difference among two ways of cipher which are asymmetric cipher which is used in
public key cryptography and symmetric cipher which is used in secret key cryptography are
discussed. These two ways of cipher are two key systems used for encryption in the field of
cryptography. Moreover, symmetric cipher can be implemented by using two kinds of cipher:
stream cipher and block cipher [11]. In secret key system, one single key is used only for
decryption and encryption. Transmitters and receivers have same secret key. Secret key’s
concept is fast and simple. However, it is not easy in keeping key safely as the number of
involved parties are increasing, secret key’s security becomes unsafe. For solving this
problem, asymmetric cipher was invented. Two keys are used in cipher algorithm. Data can
be encrypted by the person who have public key and data can be decrypted by person who
have secret key [10]. However, computing speed of asymmetric cipher is complicated and
slow.