Today's key (June 5th) has been won.

JCDenton was today's winner.  He was the first to email us the code for today, June 5th.  It was in the spreadsheet under the notes section for the Vintage Procedure Mask.  It read "This is the c0de for today: 'polar bear.'"  Congratulations to JCDenton!  Good luck to everyone for tomorrow's free key.