. An electronic mail system could be used to leak information. First, explain how the leakage could occur. Then, identify controls that could be applied to detect or prevent the leakage.

Java g array testgrades contains num_vals test scores. write a for loop that sets sumextra to the total extra credit received. full credit is 100, so anything over 100 is extra credit. ex: if testgrades = {101, 83, 107, 90}, then sumextra = 8, because 1 + 0 + 7 + 0 is 8.

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).

Consider the usual algorithm to convert an infix expression to a postfix expression. suppose that you have read 10 input characters during a conversion and that the stack now contains these symbols: (5 points) | | | + | | ( | bottom |_*_| now, suppose that you read and process the 11th symbol of the input. draw the stack for the case where the 11th symbol is