This year, we’re working to bring this “HTTPS Everywhere” mission to our ads products as well, to support all of our advertiser and publisher partners. Here are some of the specific initiatives we’re working on:

We’ve moved all YouTube ads to HTTPS as of the end of 2014.

Search on Google.com is already encrypted for a vast majority of users and we are working towards encrypting search ads across our systems.

By June 30, 2015, the vast majority of mobile, video, and desktop display ads served to the Google Display Network, AdMob and DoubleClick publishers will be encrypted.

Also by June 30, 2015, advertisers using any of our buying platforms, including AdWords and DoubleClick, will be able to serve HTTPS-encrypted display ads to all HTTPS-enabled inventory.

Google AdWords "HTTPS Everywhere" [adwords.blogspot.com]