Tags: crypto loremipsum 

Rating: 4.0

**Cipher Text**
Incompraehensibilis Conseruator.
Redemptor optimus
Iudex omnipotens
Sapientissimus omnipotens
Redemptor fabricator
Iudex redemptor
Optimus magnus
Aeternus iudex
Auctor omnipotens.

This intriguing cipher was a new challenge for me since i had not come across such a cipher before. Anyway to decoding the cipher text.
First i engaged my favorite online crypto solver https://dcode.fr which identified the cipher as a Trithemius ave maria cipher. Using the same site to decode the cipher resulted to an all caps string "*RSTHISISTRITHEMIUS*".
However trying the result as the flag led to an incorrect alert. I decided to focus on the hint about the flag being case sensitive. First i tried out modifying different characters to caps to no avail.
Some google-fu led me to the polygraphia table. I know you are wondering what that might be. Remember i did'nt explain how the cipher encrypts a secret,here's the trick.
The trithemius ave maria maps characters to words in a famous book written by the inventor of the cipher; a german abbot known as Johannes Trithemius.
The character to word mapping table is as follows
* A-deus, clemens
* B-creator, clementissimus
* C-conditor, pius
* D-opifex, piissimus
* E-dominus, magnus
* F-dominator, excelsus
* G-consolator, maximus
* H-arbiter, optimus
* I-iudex, sapientissimus
* K-illuminator, inuisibilis
* L-illustrator, immortalis
* M-rector, aeternus
* N-rex, sempiternus
* O-imperator, gloriosus
* P-gubernator, fortissimus
* Q-factor, sanctissimus
* R-fabricator, incompraehensibilis
* S-conseruator, omnipotens
* T-redemptor, pacificus
* U-auctor, misericors
* X-princeps, misericordissimus
* Y-pastor, conctipotens
* Z-moderator, magnificus.

Therefore mapping our cipher text to the table respecting case sensitivity as in the cipher led us to getting the elusive flag.
A good challenge that required some out of the box thinking.