Even lookup is not easy to be done securely. You don't want that a malicious server/database knows that you are accessing always that record. See this discussi

Even lookup is not easy to be done securely. You don't want that a malicious server/database knows that you are accessing always that record. See this discussion about how to achieve that: https://news.ycombinator.com/item?id=31668814 https://news.ycombinator.com/item?id=31668814