Hi! I'm one of the guys who designed GreenAddress and I think such technical document ('white paper') could be of interest to some people.
Direct link to the document, in pdf <a href="http://ghgreenaddress.files.wordpress.com/2014/04/greenaddressp2sh2of2hd-3.pdf" rel="nofollow">http://ghgreenaddress.files.wordpress.com/2014/04/greenaddre...</a>