Please answer all the questions:

Select the right answer and fill the blank for:

1)

Kerckhoff's Principle says that it should be assumed of a cryptosystem that an attacker knows...

A) the key and the encryption / decryption algorithms

B) the key but not the encryption / decryption algorithms

C) not the key but the encryption / decryption algorithms

D) not the key and not the encryption / decryption algorithms

2)

What are the values of w, x, y, and z after the following code snippet? Input your answers as exactly 8 binary digits with no additional characters (so like 00001111 and not like 0b00001111 or 0x0F).

uint8_t a = 0b00001111; // Assigns 00001111 to a uint8_t b = 0b10101010; // Assigns 10101010 to b uint8_t w = a ^ b; uint8_t x = a | b; uint8_t y = a & b; uint8_t z = (a << 4) | (b >> 4);

w: _______

x: _______

y: _______

z: _______

3)

The OpenSSL function EVP_CIPHER_CTX_free(ctx) does something to the structure pointed at by ctx. Which of the following best describes its function?

A) zeros and frees the structure

B) zeros but does not free the structure

C) frees but does not zero the structure

D) neither zeros nor frees the structure