code: public static int equal(int b, int c) {
      int result = 0;
      int xor = b ^ c;
      for (int i = 0; i < 8; i++) {
        result |= xor >> i;
      }
      return (result ^ 0x01) & 0x01;
    }
docs: Constant-time byte comparison.
  
  @param b a byte
  @param c a byte
  @return 1 if b and c are equal, 0 otherwise.