Power BI Secured Connectivity

I am really thrilled to see the power of PowerBI as Self Service BI..My client is in Insurance domain working with Highly Confidential data for reporting. They have in-premise SQL Databases (Relational and Analytics). Need some insights on how it can establish secure connectivity (over SSL) with on-premise databases. This is will help business to take the advantage of Power BI. Appreciate if anyone from Micorosft can throw some light on this. Thanks!