Encryption and Decryption

What is encryption and decryption?

Encryption is the process of converting plain text into a cipher text that hides the true meaning of data. On the other hand, decryption is the process of converting the cipher text back to its original form. 

Objectives of Encryption

1. Confidentiality

• This means that no third party can read or access the information. 

2. Integrity 

• No third party can alter or change the message. 

3. Authenticity

• The receiver is assured that the sender sends the information.

4. Non-repudiation 

• The sender cannot deny sending the message

Cryptosystems

A cryptosystem is a structure or scheme consisting of a set of algorithms that converts plaintext to ciphertext to encode or decode messages securely. 

Type of Cryptosystems:

• Shift Cipher

• Substitution Cipher

• Vigenere Cipher

• Affine Cipher

• Public Key Cryptography

• Quantum Key Distribution

• Elliptic Curve Cryptography

• Authentication

• Steganography