# A Rotten Riddle

Someone gave me a scrap of paper and told me if I could solve this, I would get a prize. The only thing on the paper was the following: BdvryAGlELxdckgPEApujttwsfgatIzMGURzzcyejokpsyBiUgNol

Help! What is the answer and why?

Hint1:

Solving the cipher leads to a sentence, which in itself can be solved. Spaces are omitted.

Hint2:

The title is a clue, but beware the rotten fish (there are several of them).

Hint3:

This is irrational.

Hint4:

Exponentially irrational even

Hint5:

With this cipher, a single letter is NOT strictly mapped to another letter

Hint6:

What mathematical constant (given by a letter) is found in the title?

Hint7:

I'm a programmer

Hint8:

The cipher is based on position of letter

Hint9:

Irrationality is floored before rotting away

Hint10:

Spaces shown for clarity (but don't count as anything in cipher) B dvr yAGlELx dckgPE Apu jt tws fga tIzMGU Rzzcyejo kpsyBi Ug Nol

• Initial text is for flavor only. Not an ongoing contest for anything, content is my own. Jun 6 at 20:18
• puzzling.meta.stackexchange.com/questions/1717/… Jun 8 at 13:24
• @SQLnoob there was a big hint in the puzzle before any hints were added. z100 picked up on a variant of it. But looking at it, yeah there's another tag I could have added, but I'm not familiar with all the tags on the site. Jun 8 at 16:07
• About Hint #5: "a single letter is NOT strictly mapped to another letter" Does that mean that a single letter does not always map to the same letter, or that one letter may map to nothing or even to more than one letter? Or does it mean something else entirely?
– JLee
Jun 8 at 18:06
• No more hints please, let us suffer some more ;-) Jun 16 at 11:40

The process:

For each letter in the ciphertext, raise $$e$$ to the power of its position in the string (starting with 0). Take the floor of the result and ROT the letter that many positions.

The resulting text (with spaces added) is:

a box without hinges key or lid yet golden treasure inside is hid