I think something similar to a rubix cube encompasses the most commercially relatable idea of what encryption is(and the squares in it formed "Q"). I custom made the font to go along with it. Clean, simple, and easy to understand.
Quark Address: Qb62sX3J77RV7zvVpsQd3NZAdGyUCcHQ8p

https://lh6.googleusercontent.com/-_ESAVtE1cCA/UsRExbVIvRI/AAAAAAAAA_g/wwKWLjbvIgc/s512/Quark-Logo-PNG-HighRes-Small-font.png



Here's a couple alternate versions of the same concept.
https://lh6.googleusercontent.com/-vnkQ_6HebDE/UsRE0GmhQtI/AAAAAAAAA_o/uuB5JBqjwfc/s720/Quark-Alternate-Logo-2.png
https://lh6.googleusercontent.com/-sPA0YtuGIVo/UsRE2ArdUyI/AAAAAAAAA_w/kUL0qtUo0j8/s512/Quark-Alternate-Logo-1.png





There are some really great designs posted on here! Congratulations to the winner in advance!