That was tough with the clues ....

Message:


Hash = Breakfast ...

Cyrus the Great and Potentate = Shah

Alphanumeric .... composed of letters and/or numbers. I'm assuming you meant like a cryptographic "Hash".

..... assign a numeric or alphanumeric string to (a piece of data) by applying a function whose output values are all the same number of bits in length. ....

And, then to specify “abcd dcba”.

K Man would have done the cipher and worked through the letters and then informed you of your mistake.

Riddles are tough.


Yours,