Heres a puzzle

Here is a puzzle I made up. Hope your find it interesting.

a. Solve the cryptogram:

U PROP BY THERE, USE PARS PAR THERE PROP BY THERE IYBSM PAR YUCR THER, USE YH HS. THINE BP AUQQRS PAUP PAR HGBMBSUN PROP BY GRUTARE UP YHCR YPUMR?

b. If you have solved it, answer the question.

s p o i l e r s p a c e s p o i l e r s p a c e s p o i l e r s p a c e

I had to solve this one by hand (just don't ask!). Here are the keys, in the order that I discovered them.

R -> e P -> t U -> a A -> h S -> n E -> d B -> i H -> o G -> r M -> g Y -> s N -> l T -> c Q -> p O -> x I -> u C -> m

And the answer to the question is 'yes'. Consider ROT-13, for example.

spoilers below:

first, the decrypted message:

A TEXT IS CODED, AND THEN THE CODED TEXT IS CODED USING THE SAME CODE, AND SO ON. COULD IT HAPPEN THAT THE ORIGINAL TEXT IS REACHED AT SOME STAGE?

Cipher = [abcdefghijklmnopqrstuvwxyz] Plain = [ Plain = [him_d_rou

No, the answer is 'Yes, the original text *could* be reached at some stage.'

But it's possible for a cipher to replace one character with several, for example. (Silly example: transform the message into Morse code, spelled out using 'dot' and 'dash'; then apply a substitution cipher to replace the 6 letters with others.) If the text gets longer with each successive encipherment, then the original plaintext will never