Chapter 17, Problem 47E

Program Plan Intro

Cipher:

• When encryption and decryption are performed in a particular type then it is called as cipher algorithm.
• There are different types of cipher and they are:
  • Substitution cipher
  • Caesar cipher
  • Transposition cipher
• The cipher algorithm such as transposition and substitution cipher does not greatly challenge with the modern computer systems much,
  • It is because the sender and receiver share their cipher key whenever the information is transmitted. The key that is shared creates a problem between the two parties and which may lead to risk in the future.
• To resolve the above problem, public key cryptography is utilized where in each user will be having a pair of keys.
  • The messages are encrypted using one type of key called public key and decryption is made using another key called private key.