flexi auth - A user authentication library for CodeIgniter

[eluser]skunkbad[/eluser]
My Community Auth application has an example of encrypting and decrypting data going to/from the database. The field is named `license_number`. The problem with encrypting and decrypting an email addresses is going to be that if you are using email addresses to login, depending on the specific query(ies) used to login, you may need to modify the query(ies) so that the email address is encrypted. This is slightly more complex that just encrypting data as it goes in and out of your database. Also, remember that encrypting always makes a string longer. CI's default encryption creates strings that are roughly 10 times the size of the original. You may need to adjust the length of the field holding the email address in the database table.

Have said all that, you might consider that an email address is not usually considered sensitive data. Yes, it would be inconvenient, or perhaps annoying if somebody started emailing your users, but an email address is not by itself going to lead to identity theft. We generally encrypt birth dates, bank account numbers, social security numbers, and driver's license numbers.