Crypto
DESCRIPTION
Do you know what makes a fair game?
Flag format: $CDDC19${DECRYPTED_MESSAGE}
e.g. $CDDC19${THIS_IS_THE_FLAG}
MD5("FairPlay.zip"): 3577D366F00101597169C592B93AF2A0
ATTACHED FILES
FairPlay.zip
FairPlay $ cat fairplay.html
<!DOCTYPE html>
<html>
<head>
<title>Fair Play</title>
</head>
<body>
<br><br><br>
<center><font color="green">
<h1>Do you want a flag?</h1>
<a href="javascript:alert('F_NGNU_KNDV_NQ_LHUBWYFTY')"><img src="fairplay_qrcode.png"></a>
<h1>Here you go!</h1>
</font></center>
</body>
</html>
FairPlay $ zbarimg fairplay_qrcode.png
QR-Code:R09PREdBTUU=
scanned 1 barcode symbols from 1 images in 0.01 seconds
FairPlay $ echo R09PREdBTUU= | base64 --decode
GOODGAME
Use tool http://rumkin.com/tools/cipher/playfair.php
Encrypted: F_NGNU_KNDV_NQ_LHUBWYFTY Key: GOODGAME
$CDDC19${A_FAIR_PLAY_IS_IMPORTANT}