Online Access Free 212-81 Practice Test

Which of the following are valid key sizes for AES (choose three)?

• A.256
• B.512
• C.56
• D.128
• E.192
• F.64

Modern symmetric ciphers all make use of one or more s-boxes. Both Feistel and non-Feistel ciphers use these s-boxes. What is an s-box?

• A.A substitution box where input bits are replaced
• B.A black box for the algorithm implementation
• C.Another name for the round function
• D.A shifting box where input bits are shifted

What type of encryption uses different keys to encrypt and decrypt the message?

• A.Private key
• B.Secure
• C.Asymmetric
• D.Symmetric

Uses a formula, M_n = 2^n − 1 where n is a prime number, to generate primes. Works for 2, 3, 5, 7 but fails on 11 and on many other n values.

• A.Fibonacci Numbers
• B.Co-prime Numbers
• C.Mersenne Primes
• D.Even Numbers

The most widely used asymmetric encryption algorithm is what?

• A.Vigenere
• B.Caesar Cipher
• C.RSA
• D.DES