Please be clear in answering the questions.

LAB1.docx 6. Do you think it is difficult to crack the simple Caesar cipher with brute force attack? What about cracking a substitution cipher that does not use a fixed length shift value for all letters where every alphabet in the plain text can be substituted with any of the 26 letters?. 2How? Does the time to crack the AES decrease or increase? What is the relation between key size and security? 7. What about if a weak key was used to encrypt the message? Is it possible to crack it? Open the encrypted file associated with this LAB on Cryptool and try cracking it. What is the key and what is the corresponding plain text? 8. Approximately how big is the AES key spaces? 9. Compare AES and DES in terms of security (Note that DES Key size is 56 bits) DES uses 56-bit keys-has 26 key space 7.2 x 1016 l etisalat 2:41 PM 12% LAB1.docx LAB1.docx 9. Compare AES and DES in terms of security (Note that DES Key size is 56 bits). DES uses 56-bit keys-has 256 key space 7.2 x 10 10. What is the chance that someone could use the "DES Cracker"-like hardware to crack an AES key? (Read assumptions below). In the late 1990s, specialized "DES Cracker" machines were built that could recover a DES key after a few hours. In other words, by trying possible key values, the hardware could determine which key was used to encrypt a message With the currents technology let's assume that one could build a machine that could recover a DES key in a second (i.e., try 256 keys per second). How many years it takes to crack the AES algorithm. NB: I year -31536000 seconds What do you think about the security level of AES? To put that into perspective, the universe is believed to be less than 20 billion years old