Caesar cipher uses a shift of each character by a key with a value between 1 and 255. An a with a shift equal to 3 becomes a d. For the encrypt method below, select the correct body. Assume the key shift property is accessible to the method.
Public int encrypt(int b) { __________ }
A) return (b + key);
B) return (b + key % 26);
C) return (b + key) % 256);
D) return (b + 26 % key);

Question

Quizplus · Accepted Answer

Option C is the correct choice because it ensures that the value of the shifted character will always be between 0 and 255, as required by the Caesar cipher. Option A and D do not take into consideration the range of valid characters and can result in shifted values that are outside the valid range. Option B is specific to the English alphabet, where there are 26 letters, but the Caesar cipher can be applied to any set of characters, so it is not a general solution.

Caesar Cipher Uses a Shift of Each Character by a Key