You will need to decrypt the string using a key word that should be easy to find.
Question is, which cipher?
bE CAREFUL iN CHOOSING THE CYPHER WITH THE CORRECT fiT OR YOU MIGHT SAY dOH!
cHALLENGING? iNDEED! pERPLEXING? hECKNO! eXASPERATING? rEALLY!
CONGRATULAIONS TO FLAMINGO_GIRL FOR THE FTF!