DPKFC LISLA KWMDW ERUKW XPDID BRADA TRTMO LKKGN YUEIE LDEOC VRTUM FLCVG RBSVS DTHDK WMHOG TAECO MWEYM ITWOS SEFKF BEAWK SAEOK SRSNZ RNEOR LTHIS DWZCO RQSRA MYVSI RIRGE CZIDR MMVCR HGBYE WSLSO CWMBU LGKDA DELQU BWKLF CMWGQ RYSPA EZBDA PIRGW SQSFA CLUMA RVERU ILKBA ATNOF CKWWA TCKKI IUSWD EIAPK SWSGO HCFYM SDODS MUORA TDEKU NRRSG NETHD WPHRG AEODL LOEFH BEOWC QWNAO BRUWW CCHOS OLUAC CXPWA BEAWA ROHAR O The flag is the name of the person mentioned in the message
Now, I couldnt solve this challenge while the challenge was running, because I got stuck on 04, nevertheless, here’s a quick writeup
Checking out the cipher statistics, the results turn out to be
Length:336 IC:47 MIC:60 MKA:73 DIC:23 EDI:25 LR:7 ROD:46 LDI:569 NOMOR:124 NIC:51 PHIC:47 MPIC:48 BDI:218 SDD:131 CDD:222 SSTD:60 HAS_L:Y HAS_J:N DBL:Y SERP:N HAS_#:N HAS_D:N HAS_0:N DIV_2:Y DIV_3:Y DIV_5:N DIV_25:N DIV_4_15:Y DIV_4_30:Y PSQ:N A_LDI:606 B_LDI:630 P_LDI:600 S_LDI:609 V_LDI:621 PTX:488 RDI:554 (used maximum period of: 15) ------------------------------ Winner is Bifid with 42 votes out of 100 vote distribution: Bifid 42 Trisquare 31 Seriated_pfair 17 Cmbifid 9 Quagmire 1
The best vote based on statistical analysis hints towards Bifid Cipher. Referencing this video, I got to know about cool tools.
We can use Cryptocrack to crack the cipher.
It solves the cipher, giving out the key
ZXUTVQPKINBMSWOYLERAHGDCF and the ciphertext
donnieiproposewemeetupindoveratelevenpmnextweekfortheexchangeyoushouldbeong uardasibelievesomeofourmessagesmaybeencryptedhoweveritookextraprecautionwit hthismessagebysendingmybestmancampbelltoyoutoinpersontodeliverthekeyinadvan ceiwouldliketosamplesomeofthegoodssoitwouldbeidealifyoubringafewmenofyourow ntoensurethefedscantgetinourwayrocco
donnie i propose we meet up in doveratelevenpm next week for the exchange you should be on guard as i believe some of our messages may be encrypted however i took extra precaution with this message by sending my best man campbell to you to in person to deliver the key in advance i would like to sample some of the goods so it would be ideal if you bring a few men of your own to ensure the feds cant get in our way rocco
We can see
campbell is being referrenced here, so the flag is