1. Three Square Cipher encoder

Text : ABCD efghi
Key1 : one
Key2 : two
Key3 : three
Padding Character : z

Solution:

Key1 = oneabcdfghiklmpqrstuvwxyz

Key2 = twoabcdefghiklmnpqrsuvxyz

Key3 = threabcdfgiklmnopqsuvwxyz

Grid-1

	1	2	3	4	5
1	o	n	e	a	b
2	c	d	f	g	h
3	i	k	l	m	p
4	q	r	s	t	u
5	v	w	x	y	z

Grid-2

	1	2	3	4	5
1	t	w	o	a	b
2	c	d	e	f	g
3	h	i	k	l	m
4	n	p	q	r	s
5	u	v	x	y	z

Grid-3

	1	2	3	4	5
1	t	h	r	e	a
2	b	c	d	f	g
3	i	k	l	m	n
4	o	p	q	s	u
5	v	w	x	y	z

Plaintext = abcdefghi
Split into pairs of letters (digraphs)
Pairs : ab cd ef gh i

Pad at end, if necessary
If one letter is left at the end, then pad to make it pair
Pairs : ab cd ef gh iz

Encryption :
ab `=` a(G1,r1,c4), b(G2,r1,c5) `=>` a(G1,r1,c4), a(G3,r1,c5), t(G2,r1,c1) `=` aat

cd `=` c(G1,r2,c1), d(G2,r2,c2) `=>` o(G1,r1,c1), c(G3,r2,c2), c(G2,r2,c1) `=` occ

ef `=` e(G1,r1,c3), f(G2,r2,c4) `=>` e(G1,r1,c3), e(G3,r1,c4), c(G2,r2,c1) `=` eec

gh `=` g(G1,r2,c4), h(G2,r3,c1) `=>` a(G1,r1,c4), b(G3,r2,c1), h(G2,r3,c1) `=` abh

iz `=` i(G1,r3,c1), z(G2,r5,c5) `=>` o(G1,r1,c1), n(G3,r3,c5), u(G2,r5,c1) `=` onu

Plaintext	: abcdefghiz
Ciphertext	: aatocceecabhonu

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2. Three Square Cipher encoder

Text : hello world
Key1 : one
Key2 : two
Key3 : three
Padding Character : z

Solution:

Key1 = oneabcdfghiklmpqrstuvwxyz

Key2 = twoabcdefghiklmnpqrsuvxyz

Key3 = threabcdfgiklmnopqsuvwxyz

Grid-1

	1	2	3	4	5
1	o	n	e	a	b
2	c	d	f	g	h
3	i	k	l	m	p
4	q	r	s	t	u
5	v	w	x	y	z

Grid-2

	1	2	3	4	5
1	t	w	o	a	b
2	c	d	e	f	g
3	h	i	k	l	m
4	n	p	q	r	s
5	u	v	x	y	z

Grid-3

	1	2	3	4	5
1	t	h	r	e	a
2	b	c	d	f	g
3	i	k	l	m	n
4	o	p	q	s	u
5	v	w	x	y	z

Plaintext = helloworld
Split into pairs of letters (digraphs)
Pairs : he ll ow or ld

Encryption :
he `=` h(G1,r2,c5), e(G2,r2,c3) `=>` b(G1,r1,c5), d(G3,r2,c3), c(G2,r2,c1) `=` bdc

ll `=` l(G1,r3,c3), l(G2,r3,c4) `=>` e(G1,r1,c3), m(G3,r3,c4), h(G2,r3,c1) `=` emh

ow `=` o(G1,r1,c1), w(G2,r1,c2) `=>` o(G1,r1,c1), h(G3,r1,c2), t(G2,r1,c1) `=` oht

or `=` o(G1,r1,c1), r(G2,r4,c4) `=>` o(G1,r1,c1), e(G3,r1,c4), n(G2,r4,c1) `=` oen

ld `=` l(G1,r3,c3), d(G2,r2,c2) `=>` e(G1,r1,c3), k(G3,r3,c2), c(G2,r2,c1) `=` ekc

Plaintext	: helloworld
Ciphertext	: bdcemhohtoenekc