It looks like the author anticipated that someone would try to unblur the key and left a little easter egg there :)

    >> "7965616820746869732069736E277420746865207265616C206B65792E2E2E2E".scan(/../).map { |x| x.to_i(16).chr }.join
    => "yeah this isn't the real key...."

The joke's on you

I’ve seen techniques used to reverse text that has been blurred with a fair degree of success, but that text was still easily readable in spite of being blurred. Which is weird because they must have looked at it while performing the transformation and thought “I can still read this”.

Anyhow, the hack itself is impressive. I tip my hat to them.