On the Subject of the Binary CM

A machine that knows no bounds when it comes to ciphers.

From the Binary Cipher module by Boxbomb.

Step 1: Axial Symmetry Transposition

Create five 4 by 4 grids by following the steps below:

Grid #1:

Convert the letter on screen A to a Value via the Value Table. Take the resulting value, modulo 8, plus 1. Fill the 1st and 2nd rows with the numbers 1 through 8, with the calculated value at the 1st position, and continuing in reading order.

Convert the letter on screen B to a Value via the Value Table. Take the resulting value, modulo 8, plus 1. Fill the 3rd and 4th rows with the numbers 1 through 8, with the calculated value at the 1st position, and continuing in reading order.

Grid #2:

Convert each hexadecimal character on screen 1 to get a 16-bit binary number. Fill the 4 by 4 grid with these bits.

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.

Grid #4:

Convert each hexadecimal character on screen 2 to get a 16-bit binary number. Fill the 4 by 4 grid with these bits.

Grid #5:

Take each cell in Grid #3 in reading order, and compare it to the cell horizontally opposite it in Grid #4. If the numbers are both even or both odd, place a 1 in the cell in Grid #5. Otherwise, place a 0.

Hexadecimal to Binary

0	1	2	3	4	5	6	7
0000	0001	0010	0011	0100	0101	0110	0111
8	9	A	B	C	D	E	F
1000	1001	1010	1011	1100	1101	1110	1111

Example

Screen A Value: 2
Screen B Value: 1
Screen 1: 263E
Screen 2: 2657

Grid #1	Grid #2	Grid #3	Grid #4	Grid #5
2 3 4 5 6 7 8 1 1 2 3 4 5 6 7 8	0 1 0 1 0 0 0 0 0 0 1 0 1 1 0 1	0 0 0 0 1 0 1 0 0 0 0 1 1 1 1 0	0 1 1 0 1 1 1 1 1 0 0 1 0 1 0 0	1 0 0 1 1 0 1 0 0 1 1 1 0 0 1 1

Step 2: Alphabet Transposition

Create a key using the keyword on screen 3 and the Boolean Expression on screen C. Remove the last 10 letters and rearrange the key into a 4 by 4 grid. Label the columns 1 through 4, left to right. Label the rows 1 through 4, top to bottom. This will be referred to as the Binary Key.

For each letter of the encrypted word, do the following:

• Identify what table you’re using based on the Nth letter of the encrypted word.
• Find the Nth letter on screen 4 in the Binary Key.
• Shift the X marks down equal to the row in the Binary Key.
• Shift the X marks to the right equal to the column in the Binary Key.
• Take all the positions of the X marks in reading order and take the binary digits of their positions from Grid #5.
• Convert the 5-bit binary into a letter via the ASCII Translation Table to get your Nth decrypted letter.

ASCII Translation Table

A	00001	H	01000	O	01111	V	10110
B	00010	I	01001	P	10000	W	10111
C	00011	J	01010	Q	10001	X	11000
D	00100	K	01011	R	10010	Y	11001
E	00101	L	01100	S	10011	Z	11010
F	00110	M	01101	T	10100
G	00111	N	01110	U	10101

A	B	C	D	E	F	G	H
X-X- X--- -X-- --X-	XX-- -X-- -X-X ----	XX-- X-X- ---- --X-	XX-- ---- ---X X-X-	XXX- ---- X--- ---X	XXX- -X-X ---- ----	XX-- XX-- -X-- ----	XX-- X--- -XX- ----
I	J	K	L	M	N	O	P
XXX- ---- --XX ----	XX-- ---X --X- X---	XX-- -X-X ---- --X-	XX-- -X-X -X-- ----	XX-- -X-- X--- --X-	XX-- --X- --XX ----	XX-- ---X -X-- --X-	XX-- ---X X--X ----
Q	R	S	T	U	V	W	X
XX-- --XX ---- ---X	X-X- X--- ---X X---	XX-- ---- X-X- --X-	XX-- X--X ---- --X-	XXX- -X-- ---- X---	XX-- --X- X--- X---	XXXX X--- ---- ----	XXX- ---- ---- X-X-
Y	Z
X-X- X--- -X-- X---	X-X- -X-- X--- X---

Example

Encrypted Word: LVZG
Screen 4: BTJE

	1	2	3	4
1	S	T	A	R
2	B	C	D	E
3	F	G	H	I
4	J	K	L	M

1 0 0 1 1 0 1 0 0 1 1 1 0 0 1 1

- - X - - - - - - X X - X - X -

01101 → M

1 0 0 1 1 0 1 0 0 1 1 1 0 0 1 1

- - X - - - X X X - - - - - X -

01001 → I

1 0 0 1 1 0 1 0 0 1 1 1 0 0 1 1

- X - X - - X - - X - - - X - -

01110 → N

1 0 0 1 1 0 1 0 0 1 1 1 0 0 1 1

- X - - - - - - X X - - X X - -

00100 → D

Decrypted Word: MIND