Reader challenge explained

As I promised, here's a brief explanation of the reader challenge I posted earlier. (Deadlines in the summer? Baaad idea.) I will leave decoding as homework though.

Spoiler alert!

I. Almost trivial

This is a simple substitution cipher using my haxor handle (repeated characters removed) as the key:

WINDYTABCEFGHJKLMOPQRSUVXZ
ABCDEFGHIJKLMNOPQRSTUVWXYZ

Reversal is almost trivial due to the distinct pattern it leaves in the letter frequency spectrum. "Almost", because there is an added challenge in the language used.

II. Shouldn't be very hard either

This message was transformed into audio with the Hellschreiber teleprinter. There's no further encryption. Some people noticed that there's a hint in the audio metadata; this was unintentional.

III. Might take some effort

A visual encryption scheme. A message is encoded in the difference of these two random dot patterns. I tried to add noise into the encoded message to make the resulting similarities in the patterns less obvious to the eye.

IV. NSA-grade

Okay, it's not really NSA-grade. But it's a Playfair cipher, using the following key:

$square =
  "WINDY".
  "ABCEF".
  "GHKLM".
  "OPQRS".
  "TUVXZ";

Whitespaces and punctuation was removed, and full stops were converted to "STOP".

I was surprised at how many people actually reversed this!

Reader challenge: Obfuscated messages

I'm under the impression that some people are actually reading this blog. So, for the amusement of my readers, here are some little puzzles to be solved.

Send your solutions to windyoona at gmail dot com and I'll post your name or handle under the puzzle(s) you solved!

The challenge is over now. For more problems like this, take a look at Oona's puzzle corner in PoC||GTFO 0x09.

Ⅰ. Almost trivial

"Wjd bwpq qbkr pgwcj qby Ewiiyouknf?
Nkhy qk hx wohp, hx iywhcpb ikx!
K towiekrp dwx! Nwggkkb! Nwggwx!"
By nbkoqgyd cj bcp ekx.

'Quwp iocggca, wjd qby pgcqbx qksyp
Dcd axoy wjd achigy cj qby uwiy;
Wgg hchpx uyoy qby ikokaksyp,
Wjd qby hkhy owqbp krqaowiy.

II. Shouldn't be very hard either

III. Might take some effort

IV. NSA-grade

UGYPY PCTLX ISRLF OCWZG LDAXN DMAPS LFHYR ZQFWD UGWBO ZPQUG YPYPS FRGYE PDXLD YGSYQ
DBXPQ PDPTW IGSGB PCTCD TWRFD LYCPS DFEOR ZOZPQ PGDAQ CTAGS YQDBX BSQPW SPZOB WNEWD
UGWBO GDHFZ WTUHV UBPEW WQNYF BLBAG OFESD BDYSA WSXPR ZRZWT SIFRN DELDL YRBWI RPWSP
ZOLXW PZPMD OZPQN HWQYG EWFLP WRFRD RLFNW VPBFO GWPQW UYPFI UGFEG BPDZW SAUGG WOTTR
YLSOZ RWTUB WKRLU GPSOU GBUWF GLBXL OZTWO ULBWC PYGRT RLCWE UGYHN DPVDP NDHMD ZDFZS
FMPDC DYRLB GBNLN DERDF ZUCDE LLEGP OQWUE GWUWZ POCXC DSASF AQVIX OISAR RHADG PEGFO
EOLXF ATHLD FRESS GUGXA DPWCU WXCGE DYOZP QDACF MHWBY QINRD GEGDF WOSFL FLCFP LLXIN
UGLOG WWUXI XBOZP QURPW SPWAF OCWLD XOGTX ENDEO DMRTQ GNDHM WUZUR LGFYQ WTUPA DFOGB
XEMDM GPSAX GBYCN UFALD AXASX PNDBK FRHIV AEODX DBILY HRFME INUGL OFBXW WHDNZ WZFWT
UPYPL BEWAG RFTEA VMDUG FRGBR BSACW ALTLC WILFB GDFWO QLXBK LEWUE GWUZU XMARW QDCPY
ELOZP QPBZS PTOZB ELBAG QZLXF ZUWEZ ABDYH YHDWG SDOZP QUGCD FBAZD CRZOP BMYPG WZUDP
ADFOE GGSOZ NDEQL EBHRL OZPQB HLRDB XCFOR BKQSA IXOZA WPTRE GBXCE BZPLE PBLZG SXLOB
NDUGC WBCXH DRAXA TVIYR WTSIA XZUPB ORTBN DXWEW DYFMD BERWU ZURLG FDIGP NIFOZ RPSDX
WZPOL DCDTA HDHSL ECBER IMEWC FDLDN IKYPZ OYHAR DCSAU GFLPO VALRF COEXA YLFLC FSOSA
UGFCL RHWCW QPHDE FOZPQ FOEWA XFFAV NUBLY PEMBW PLEWC FDLDC ZUOEP SYNWC SDCWI LBLEW
BEPBC XLEXO BIHSM PFIHI DQCTL RDRND MOSGA RAZLB GSOZC BEZEM NDKAF OFRSA UGLEF WOZPQ
LBQPN DXAWR TPUZW TLFUG LRWUZ URLGP ZPBDI KBCWU LEFIP BGFDY PBZML RDRTA CFMHW BYQCW
YNQSP OHYRF WXTOT GDYRF DLPBG FWGDC EOMDW EXAOZ PQUGC DLBOE YPLEP BPMGW INUGB AGEPT
PDPMW TFNWV PBETC WYILE SPXCG AFWOZ PQLBO FELEO HDUZX GFLCW OFNYF NWVPB OBOZP QNYWQ
NYFBW SVHDC IGYHO ZPQWS VXFCL DCDCD XAOXB WDNWK BELRF CPDZW VITBA GXLPY XLRHD BYRWT
OBDYA SOXLB XLOZS AUGAD FWGPL FDPFE WULEW TUGFL UGBLT CPDPT RFURG RWUOF DYXOB IHSMP
SALBQ EXHBR PWSPZ OWTOU

Update: Explanations are in another post, so this is kind of closed.

Scoreboard

	I	II	III	IV
Alpak HD			✓
Ben		✓	✓	✓
Claude Vaillancourt	✓		✓	✓
Denis Liliom			✓
Hans Van Ingelgom	✓	✓	✓
inquisitas			✓
JasonD			✓
Karim	✓
Ken Arthur	✓
Liwei	✓		✓
Miguel Lechón	✓		✓
Nicolas Vanderavero	✓
Ole Andre Noss		✓	✓
Shaun Hey	✓	✓	✓	✓
Stefano			✓
Steve Pordon	✓	✓	✓	✓
Tim James	✓		✓
Zac Watts	✓