Kryptos 2018 Challenge 3:

Dear Crypto Consultants:

We are trying to break up an international internet Trolling operation that has the potential to cause harm to civilians.  The group, led by an individual who goes by the name of "Grendel", has moved well beyond influencing social media sites.  Grendel is now using a few well-placed individuals to infiltrate into some local grass roots organizations in order to convince them to participate in some demonstrations and/or protest marches.  Grendel has infiltrated organizations from different sides of the political spectrum and plans to have each of them protesting on the streets on the same day. We fear that the results could turn disastrous and, possibly, violent.   Up until now, we have been able to intercept their communications via some computer and phone surveillance systems we have in place.  However, as we get closer to the day of the Big Event (this is how Grendel refers to the operation), they have started encrypting their messages.  Grendel has sent one encrypted message to his group of trolls several days ago, but now there has been no chatter on any of the usual communication links.  We feel they have gone "silent" and that the Big Event must be close at hand.  But, we have no idea when or where this event is planned to take place.  This is where we need your help!

 A copy of the last encrypted message from Grendel is given below.  While we do not know who Grendel is, we have identified one of his trolls.  An on-site security team managed to find a crumpled up, coffee-stained, piece of paper that might just hold the key to their encryption scheme.  I hope you can make some sense out of it.  If you manage to decrypt this, please let us know as soon as possible!

Sincerely,

G. W. Oman.

Hdqtrs.

 CT:

WPIQT BAVNV UKQZP NFPDW VCZMX XWWWU MCEHA VZVSN WNWOE FBEFF OWSWE OFHWG FHQAX LDEIA BKWTX KZPII OLLHJ GLQBY AEKVQ SEBGN VUEMQ NHADS HEXKL AAHOW NBOWP QGOID XAQUH NFKSR PAATX FUCTT FOLNW ZVOWV NUKVQ SEBGB VTAWQ CLCKN SQXYC KNPAN KWWEM QIOAT EUFPB LTEHF TELOW KUQHU OHYVF JPHNA QQBPT XSVCV MJLEB QUDUN AQCTC KNKUQ HUOXF NWOVQ KSRWO TFBRI FIIQK QZNUK JWLMF HWGKF OPSYO RVVPA ANRVE JUWTP WAVVM BNWAX OUOMH SUHWW AEFLI QJLES PVLAE KFJLI ZEHBC SN

[link to a text file with the CT]

[link to the piece of paper]