4 A certain symmetric encrption system El uses the following secret key (KI) for confidential communication between A and B FEA01FAA3459012D (hex) A decides to deliver this secret key (K1) to B by transmitting it over the same insecure channel using a second encryption scheme E2 a- What method of encryption would you suggest for E2? b- Based on your suggestion, what would be the size in bits of the key (K2) used in encryption system E2? c- If a system of computers has the ability to try 64 keys every 100 microseconds in an effort to decipher the message encrypted by E1 by brute force, how long (on average) would it take to break the code? d- Is El computationally secure