I met a girl and wow! it's like she's my muse (no, I am not an ancient Greek :) ). She inspired me to build an app that will have a simple riddle that will say

"Θελεις να βγουμε?" ("Do you want to go out with me?" in Greek).

I'm trying to think of a simple math equation that would result in +1, and then having the message be the greek letters that are one position before the letters in my message:

ηδκδθρ μω αβξτλδ?

where if you take the previous letter from the Greek Alphabet, the intended string will be revealed!

However, I am worried of how to hint to her to do this? I mean, I am in Computer Science and adding 1 from the ASCII code seems obvious to me, but she is not in CS. So how do I hint to her (without actually making it too easy) that the +1 means that she should take the previous letter for every letter in the given string?

• I would be very happy if the downvoter suggested how I could improve this question. :) Nov 24 '16 at 16:20
• How is that a riddle? If I understand you correctly, it's a ROT-1 cipher with the greek alphabet as the charset.
– user14478
Nov 24 '16 at 16:22
• @BeastlyGerbil It doesn't have to be a puzzle to be on-topic, though.
– user14478
Nov 24 '16 at 16:23
• BTW, I think you mean you have to take the next letter to reveal the plaintext.
– user14478
Nov 24 '16 at 16:33
• But "So how do I hint to her (without actually making it too easy) that the -1 means that she should take the previous letter for every letter in the given string?" is still incorrect if you give her the string ηδκδθρ μω αβξτλδ, since that means eta would become zeta .
– user14478
Nov 24 '16 at 17:20

This seems to be a rot 1 cipher so you could hint that by saying