How does the Google's smart updates technology work?

Question

I know the basics: they compute a difference between two versions and send it to the user's device where it is deployed. Precisely, I am interested in 2 questions:

1. What changes were made to the server's software and what changes were made to the Android Google Play Store application?
2. What algorithm is used to compute difference between the two application's versions?

Thank you.

Answer 1

OK, it seems that they use GDIFF algorithm that computes differences between streams. More information about GDIFF algorithm and GDIFF format here: http://www.w3.org/TR/NOTE-gdiff-19970901, http://gdiff.codeplex.com/.