Which statement about the Caesar cipher is true?

Which statement about the Caesar cipher is true?

• A. It uses a random substitution per letter.
• B. It changes every letter to a symbol with no shift.
• C. It is a modern, widely used encryption standard.
• D. It shifts letters by a fixed number.

Answer: (D)

The Caesar cipher works by shifting every letter in the plaintext by the same amount in the alphabet. Because the shift is fixed, the mapping is the same for all letters, which is why the statement about shifting letters by a fixed number is true. It isn’t a random substitution applied per letter, and it doesn’t replace letters with symbols without any shift. It’s also not a modern encryption standard; it’s an ancient method that’s much simpler than today’s algorithms. For example, with a shift of three, A becomes D, B becomes E, and Z wraps around to C. This fixed-shift nature is what makes it easy to crack by trying all 26 possible shifts.

The Caesar cipher works by shifting every letter in the plaintext by the same amount in the alphabet. Because the shift is fixed, the mapping is the same for all letters, which is why the statement about shifting letters by a fixed number is true. It isn’t a random substitution applied per letter, and it doesn’t replace letters with symbols without any shift. It’s also not a modern encryption standard; it’s an ancient method that’s much simpler than today’s algorithms. For example, with a shift of three, A becomes D, B becomes E, and Z wraps around to C. This fixed-shift nature is what makes it easy to crack by trying all 26 possible shifts.