Code Breaker
Many modern codes are based on two very large prime numbers multiplied together.
This problem is based on a code using two different prime numbers less than 10. These two primes have been multiplied together and the resulting number has been used to shift the alphabet forward to new letters, assuming that A is at position 1, B at position 2 etc. For example, if the two prime numbers were 2 and 3, then to make the code, the alphabet would be shifted forward by 6 places. A would become G, B shifts to H and so on.
Which way will you need to shift the letters to decode?
When you have deciphered the code, there will be one word which will remain coded. You can decipher this word by adding the two prime numbers together and shifting the letters again.
Can you find the doubly coded word in this sentence?
JZF SLGP FUDFNHG TE
Make a list of all the prime numbers less than 10.
What are the different multiplication combinations you need to
try?
Remember if the code was made by shifting the letters forward, to break the code you will need to shift the letters by the same number but backwards.
I tried different pairs of prime numbers that it could be, until I found a pair that worked. The pair was 3 and 5, so I used 15 forwards on the red one, and got YOU HAVE UJSUCWV IT. So the third word was doubly encoded. Then I used 8 forwards on the blue one, and found that the third word was CRACKED.