Which of the following block cipher modes XORs a plaintext block with the previous ciphertext block (or an IV) before encrypting it?

If the initial state is 0110, what is the period of the LFSR?

After the round 1 SubBytes layer.

What is the purpose of a security proof?

¬B1{“version”:”1.1″,”math”:”\neg B_1″}

Which of the following best describes the Salsa20 stream cipher?

How many possible answers to each quiz question would be required so that a 16-question quiz has at least 128 bits of entropy?

Given bits b1 and b2, what does b1 ⊕ b2 produce?

How many questions would be required so that a quiz has 128 bits of entropy?

After the round 1 ShiftRows layer.