5. DES: Suppose we have an enhanced version of DES that uses 128 bit keys instead of 56 bit keys. a. Ifa DES chip can do three decryptions in five clock cycles and it is clocked at 10 GHz, compute the average and worst case time (in years) required to do a brute force attack with a known plaintext. How does this compare with the age of the earth which is estimated to be 4.55 billion years? b. If the chip speed doubles every 18 months (Moore's Law), how many years do we have to wait before this enhanced version can be broken by brute force in 24 hours? How do the results change if 10000 chips run in parallel in each case? Compare the times and comment on the results 5. DES: Suppose we have an enhanced version of DES that uses 128 bit keys instead of 56 bit keys. a. Ifa DES chip can do three decryptions in five clock cycles and it is clocked at 10 GHz, compute the average and worst case time (in years) required to do a brute force attack with a known plaintext. How does this compare with the age of the earth which is estimated to be 4.55 billion years? b. If the chip speed doubles every 18 months (Moore's Law), how many years do we have to wait before this enhanced version can be broken by brute force in 24 hours? How do the results change if 10000 chips run in parallel in each case? Compare the times and comment on the results