What is this line doing?

What are the two 26s for?

This is where we use the ApplyShifttoASCIICodeForCharacter functionTo get the encrypted text.

How do we decrypt?

The “rail fence”

T t a Jh i h r M oi s e m r ns y e s

Size = 4

The “rail fence”

T t a Jh i h r M oi s e m r ns y e s

Size = 4

The “rail fence”

T

h

i

s

i

s

t

h

e

a

r

m

y

M

r

J

o

n

e

s

Size = 4

The “rail fence”

T t a J

h i h r M o

i s e m r n

s y e

s

Size = 4

How the algorithm works

2 Counters

T t a Jh i h r M oi s e m r ns y e s

Counter one starts at the beginning and loops once only

Counter two starts at counter one and loops to the end

T t a Jh i h r M oi s e m r ns y e s

T t a J

h i h r M oi s e m r ns y e

s

For Count1 = 1 To SizeOfRailFence

While Count2 < OriginalText.Length Count2 = Count2 + SizeOfRailFence