Entrance Test Caesar Cipher Hints

YNU  DWRKY  WJZ  HAP  OHEL  PDA  ZKCO  KB  SWN

The quickest way to solve a Caesar Cipher is by using Excel. Simply enter the code, or just one of the enciphered words – e.g. HAP – at the top of 3 columns, using a separate column for each letter. Then continue the alphabet in each column (using copy and paste for speed) until you make a word.

H A P

I B Q

J C R

K D S

L E T    is a word. We may have found the shift! Check against the rest of the cipher.

You can do this on paper too, without copying out columns and columns of the alphabet, using logic.

1. Almost every word contains a vowel or y
2. Look for the shortest word – here KB
3. There are 3 Ks in the cipher, but only 1 B, so K is probably a vowel.

4.. To encode i as K, we would shift forward 2 letters

5. So test a +2 shift against any other short word. Let’s pick YNU

Output Y Input w Transition -2
Output N Input l Transition -2
Output U Input s Transition -2

wls is not a word. Therefore the coding transition is not +2.

6. Try the next closest vowel – o.
7. To encode o as K , we would shift back 4 letters

8. So test a – 4 shift against the same short word – YNU.

Output Y Input c Transition +4
Output N Input r Transition +4
Output U Input y Transition +4

Cry is a word! Looks like we’ve cracked the code!

Try decoding the rest of the quotation, using +4 to decode.

Got it right? Why not make up your own Caesar code to test out your friends?