We have a system that searches user names. Since the names are encrypted (getting this working was tricky on the back end too), we can't accept an empty search or one with one letter, since that would start decrypting too many names.
We've been thinking about how to convey to the user that they've got to input a minimum number of letters, and nothing obvious is jumping out at us. Some ideas:
- We could gray out the search button until we get the minimum. The obvious drawback is that people might well think the search feature is somehow not active at all.
- We could warn people after the fact "sorry, you need to type at least 3 letters to search", but that's kind of annoying. Probably the best solution so far though, since most people will likely search on an actual name.
- More work on the backend might be able fix things, but searching and sorting encrypted data is "not easy", and might not be a good compromise, since there are plenty of other things that need doing with the system too.