How to find a precondition or postconditions in python , if possible with an example.(not a difficult one please).

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).

Leo is a recruitment executive for a large company. he has identified new labor resource requirements in both the marketing and production departments. what should be his first step in recruiting candidates for the positions? a. conduct background checks of candidates b. make job offers c. arrange interviews d. conduct reference checks e. place job ads on job sites

Which of the following is not a key player in the sale of travel products?