There are 10 questions broken up into four different sections: I - Short Essays (20 points), II - Long Essays (30 points), III - Problem Solving (15 points), and IV - Programming (45 points). Start NOW and upload your answers in a single PDF file in Moodle when done. Good luck! I. SHORT ESSAY (20 points) 1. (2 points) What are the essential ingredients of a symmetric cipher? 2. (2 points) What are the two principle requirements for the secure use of symmetric encryption? 3. (2 points) What is a message authentication code? 4. (8 points) What six properties must a hash function have to be useful for message authentication? 5. (6 points) What security areas are addressed by IEEE 802.11i? II. LONG ESSAY (30 points) 6. (20 points) For Wireless Encryption Protocol (WEP), data integrity and data confidentiality are achieved using the RC4 stream encryption algorithm. The transmitter of the Medium Access Control (MAC) Protocol Data Unit (or MPDU) performs the following steps, referred to as encapsulation. i. Select initial vector (IV) value. ii. Concatenate IV value with the WEP shared key to form the seed, or key input, to RC4. iii. Compute 32-bit cyclic redundancy check (CRC) over all bits of the MAC data field and append to the data field. iv. The result from iii is encrypted using RC4 to form the ciphertext block. v. The plaintext IV is prepended to the ciphertext block to form the encapsulated MPDCU for transmission. a. (5 points) The MPDU changes slightly based on the MAC protocol used; however, all MPDUs have five common fields. Draw the MPDU and describe each field b. (5 points) Draw a block diagram illustrating the encapsulation processed describe in the steps above. c. (5 points) Describe the steps at the receiver end to recover the plaintext and perform the integrity check. d. (5 points) Draw a block diagram showing part b. 7. (10 points) List and describe the five operational phases of IEEE 802.11i. CMP 647 Mobile and Wireless Security – Dr. Kelly Due before midnight Friday, 6 March 2015 HW#2 (100 points) Spring 2015 III. PROBLEM SOLVING (15 points) 8. (10 points) Simple cipher. Given the ciphertext below, crack it using any method to find the plaintext. a. Ciphertext: Si spy net work, big fedjaw iog link kyxogy Plaintext: b. Ciphertext: Cf lqr'xs xsnyctm n eqxxqgsy iqul qf wdcp eqqh, erl lqrx qgt iqul! Plaintext: 9. (5 points) Ceaser cipher. Given the plaintext below, generate the appropriate ciphertext using the Caesar