On the Subject of Military Encryption

For fans of products with the word “tactical” in the name.

Use the rank insignia on the module to find one of the keysquares in the page below. This keysquare is used by the module’s encryption and does not change on a reset or a strike.

Pressing the ! button activates the module, starting a 90-second timer on the small display and displaying an encrypted word on the large display.

The encryption process used by the module uses the obtained keysquare and a secret four-letter transposition key, made up of the letters ABCD in some order. It is as follows:

Example
Key: 5, CDBA.
Word: FAAGGFAX
C D B A
G A A F
F X G A
Result: NEON

• Each letter is converted into an ordered pair of letters (Row, Column) and those ordered pairs are written out in sequence.
• The resulting string is written into a 4×2 grid row by row from top to bottom and its columns are reordered according to the transposition key. The resulting message is read out in column order.

The module will perform a soft reset every time the timer reaches zero, and will perform a hard reset every three soft resets. The LEDs will flash green on a soft reset, and red on a hard reset. The encrypted word will change on a soft reset, and the column the encyrpted words are chosen from, as well as the transposition key, will change on a hard reset.

To solve the module, enter a word from the column the encrypted words are chosen from that has not appeared in any prior soft resets for this hard reset, encrypted using the current keys.

Your input will be submitted automatically after eight letters; use the ! button to clear it. An incorrect submission will cause a strike and deactivate the module.

ACID	ANKH	BOAR	COPY	DAWN	FANG	GERM	HEIR
HOWL	ISLE	KNOT	LADY	LION	MIKE	NEON	OKAY
ORCA	PAST	QUIZ	RAID	SCAN	SILO	SMOG	TANK
TECH	TRIO	USER	VAST	VICE	WARD	YETI	ZINC

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

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

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

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

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

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

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

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

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

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

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

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