Network security by block ciphers

الملخص EN

This paper reviews some of the encryption models through the block cipher technique used for the data encryption process.

As an introduction, we explained Classical Substitution Ciphers by two example models (Caesar Cipher and Vigenere Cipher).

They are followed by a block cipher which is presented by multiple encryption triple DES and block cipher modes of operation.

Multiple encryption DES algorithms are using two or three keys to make the encryption process more complex.

But still using a 64-bit fixed blocks message and also wasted a lot of time during the encryption and decryption process.

So we need some ways to encrypt and decrypt arbitrary quantities of data.

This paper presents five block cipher modes of operation to cover a wide variety of applications and can be used with any block cipher.