## On the Subject of Binary Cipher

!bomb time. How do I use it?

On this module, you will see three screens, a keyboard, two small square buttons, and a screen that displays the current page you’re on.

Pressing the right square button will take you to the next page. Pressing the left square button will take you to the previous page. There are two pages.

The top screen on the first page will show a 16-digit binary number.

The middle screen on the first page will show a keyword.

The top screen on the second will show a single letter.

The bottom screen on the second page will show another 16-digit binary number.

Follow the steps below to determine what to submit:

### Step 1: Axial Symmetry Transposition

In this step, you are going to create five 4 by 4 grids.

#### Grid #1:

Take the battery count, modulo 8, plus 1. Fill the first and second rows with the numbers 1 through 8, with the calculated value at the first position, and continuing in reading order.

Take the port count, modulo 8, plus 1. Fill the third and fourth rows with the numbers 1 through 8, with the calculated value at the first position, and continuing in reading order.

#### Grid #2:

Take the 16-digit binary number shown on the bottom screen of the second page, and fill the 4 by 4 grid with these digits.

#### Grid #3:

Take each cell in Grid #1 in reading order, and compare it to the cell horizontally opposite it in Grid #2. If the numbers are both even or both odd, place a 1 in the cell in Grid #3. Otherwise, place a 0.