DES Attacks Quiz

What is the first step in the DES algorithm process as shown in the diagram?

• L0 = R0

• PERMUTATION (IP)

• R1 = L0 ⊕ F(R0, K1)

• L16 = R15

According to the diagram, how many rounds of processing are there in the DES algorithm?

• 15 rounds

• 16 rounds

• 14 rounds

• 10 rounds

What operation is depicted by the symbol '⊕' in the DES algorithm diagram?

• Multiplication

• Permutation

• Bitwise AND

• Bitwise XOR

What is the final step in the DES algorithm process as shown in the diagram?

• PERMUTATION (IP)

• L16 = R15

• PERMUTATION (IP-1)

• R16 = L15 ⊕ F(R15, K16)

What is another name for the Round / Cipher Function F(Ri-1, Ki) in cryptography?

• Expansion Function

• Combiner Function

• Substitution Function

• Permutation Function

In the diagram, what is the bit size of the input to the expansion box (E)?

• 32 bit

• 48 bit

• 64 bit

• 128 bit

After the expansion box (E) and before the S-Boxes, what operation is performed with the key Ki and the expanded data?

• Addition

• XOR

• Multiplication

• Division

What is the bit size of the key Ki used in the cipher function diagram?

• 32 bit

• 48 bit

• 64 bit

• 128 bit

What is the final operation performed in the cipher function diagram before producing the output?

• Expansion

• XOR

• Substitution

• Permutation

What does the "F" function in a DES round use as its inputs?

• L_i and K_i

• R_i-1 and K_i

• L_i-1 and R_i

• R_i and L_i-1