another person knowing the ID of the record in the database is not what you should be worried about, the only way this does anybody any good is if they have access to the database directly.
and in that case, you're best hope is to have the sensitive data in each of the columns encrypted.
It will not speed up the database either, if anything it will slow it down since the values will be in text. text values take up more space in the database than numbers do, thereby slowing down any indexing.
this is an ineffectual strategy for protecting data in the database.