ECES - Practice Exam Questions with correct answers

Which of the following is generally true about key sizes? a. Larger key sizes increase security b. Smaller key sizes increase security c. Key size is irrelevant to security d. Key sizes must be more than 256 bits to be secure - correct answer a. Larger key sizes increase security How did the ATBASH cipher work? a. By shifting each letter a certain number of spaces b. By Multi alphabet substitution c. By rotating text a given number of spaces d. By substituting each letter for the letter from the opposite end of the alphabet (i.e. A becomes Z, B becomes Y, etc.) - correct answer d. By substituting each letter for the letter from the opposite end of the alphabet (i.e. A becomes Z, B becomes Y, etc.) DES has a key space of what? a. 2^128 b. 2^192 c. 2^56 d. 2^64 - correct answer c. 2^56 Which of the following are valid key sizes for AES (choose three)? a. 56