3.3. Exposed Data
Another concern regarding databases is the exposure of sensitive data. Whether you're storing credit card numbers, social security numbers, or something else, you want to make sure that the data in your database is safe.
While protecting the security of the database itself is outside the scope of this book (and most likely outside a PHP developer's responsibility), you can encrypt the data that is most sensitive, so that a compromise of the database is less disastrous as long as the key is kept safe. See Appendix C for more information about cryptography.