Mike, this article was really helpful. You covered a couple things here that I just didn't find in a lot of other reading. In particular the brief discussion about how expensive it can be to open symmetric keys was helpful. Mostly though, I am grateful for the piece you put in about searching on encrypted values. I have an app where I need to search a table full of 32,000+ rows for a specific SSN value that is encrypted. It was taking a ridiculous amount of time to return my results so I think when I implement your solution using checksum, it will help a ton!