Encryption and decryption operations

1. Given short notes on RC5 key expansion process.

2. Explain about RC5 encryption and decryption operation in detail. 12. What are the advantages of RC5?

3. What is IDEA? Explain in detail about IDEA encryption and decryption operations.

4. Explain in detail about Blowfish encryption and decryption operations.

1. What is the total number of exclusive-or operations used in DES?

2. What is the purpose of the permutation in DES?

3. Explain about single round operation of DES in detail.

Consider a cipher composed of 16 rounds with an input bit block length of 64 bits and a key length of 64 bits. Input bits: 10101010 10101010 10101010 10101010 10101010 10101010 10101010 10101010; Key bits: 00111011 00111000 10011000 00110111 00010101 00100000 11110111 01011110. From the input bits and keys, find out the first eight round sub-keys.

Solution: