Transcript An Improved Encryption Scheme

Why Is This Code Easy To Break?
In this encryption scheme, letters are input and then
encrypted in the following way:
Each letter is assigned a numerical value. “A” is assigned
a value of 1, “B” is assigned a value of 2, C = 3, and so on
for all the letters of the alphabet up through Z = 26.
Each value is increased by 2. If the increased value is
greater than 26, the value is divided by 26 and we use
the remainder. This is a process known as modular
arithmetic in base 26.
The values are mapped back into letters. So a value of 3
would be mapped to the letter C.
Example: The letters of the word ZAP are mapped to the
numbers 26,1,17. These values are each increased by 2
to result in 2,3,19. The values 2,3,19 are then mapped
back to the letters BCR.
What Is This Code Easy To Break?
ANSWER: The pattern is fairly easy to recognize! For
example, the word YAM is mapped to the values Y=25, A=1,
and M=13. These values are increased to 2,3,15 so
YAM is encrypted as ACO
If you simply have two strips of paper containing the
alphabet repeated. You line up the bottom strip so that the
encoded word corresponds to a real word. The number of
places the bottom strip is shifted reveals the coding
strategy.
To improve this encryption scheme, we could transpose all
values as part of the scheme. So 1 becomes 26, 26 becomes
1, 2 becomes 25, 25 becomes 2, etc.
For More Info, See An Improved Encryption Scheme