Computers) 2 questions

3. bob is arguing that if you use output feedback (ofb) mode twice in a row to encrypt a long message, m, using the same key each time, it will be more secure. explain why bob is wrong, no matter what encryption algorithm he is using for block encryption (15 points).

Which of the following is not a source of sustainable raw materials? a) coal mine b) flick of sheep c) cotton plantation d) line forest.

Consider the following function main: int main() { int alpha[20]; int beta[20]; int matrix[10][4]; . . } a. write the definition of the function inputarray that prompts the user to input 20 numbers and stores the numbers into alpha. b. write the definition of the function doublearray that initializes the elements of beta to two times the corresponding elements in alpha. make sure that you prevent the function from modifying the elements of alpha. c. write the definition of the function copyalphabeta that stores alpha into the first five rows of matrix and beta into the last five rows of matrix. make sure that you prevent the function from modifying the elements of alpha and beta. d. write the definition of the function printarray that prints any onedimensional array of type int. print 15 elements per line. e. write a c11 program that tests the function main and the functions discussed in parts a through d. (add additional functions, such as printing a two-dimensional array, as needed.)