Google engineer Matt Cutts recently hinted at that in March, The Wall Street Journal reports.
According to the report, Cutts has had private conversations where he has expressed Google's interest in implementing encryption in its search results. The aim is to rid search results of spam sites, according to the WSJ.
Google's search algorithm is designed to encourage and discourage certain practices among Web sites. For example, it penalizes sites with malicious software and ones that load slowly.
In the last few years, Google has encrypted Gmail, Google Maps, and Google Search. After the revelations of the NSA's wiretapping, Google started encrypting traffic between its data centers.