Make a 4×4 rectangle

2	j	n	t
o	p	s	8
o	k	y	f
z	5	v	7

Read in a zigzag pattern (or you could reverse rows 2 & 4).

2jnt8spookyf7v5z

An old greek historian will help you

Let’s start by making pairs

43 15 54 53 14 43 15 11 45 42 11 43 14 43 24 35 44 52 15

While it’s probably not obvious when you first start out, by experience you’ll remembers that pattern as a Polybius square.

Here’s what it looks like

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

Each pairs correspond to a grid coordinate. 43 is S, get the corresponding letter for each pair.

seyxdseaurasdsiptwe

7yxd7aurasd6p2e

What cipher usually start with a N

When counting 24 characters, Base64 should come up to mind. Base64 passcodes usually start with a capital N. We have that n at the end of the string. Let’s reverse it.

nfnbnvzjsu5tudfsrvu5vdjw

Now let’s make those letters all caps.

NFNBNVZJSU5TUDFSRVU5VDJW

Convert Base64 to text

4SA5VIINSP1REU9T2V

That doesn’t work, need a but of tweaking. Roman numerals, the 5 should be a V and VI is 6.

4sav6inspireu9t2v