Is it worth encrypting email addresses in the database?

Question

I\'m already using salted hashing to store passwords in my database, which means that I should be immune to rainbow table attacks.

I had a thought, though: what if s

Answer 1

A copy of my answer at What is the best and safest way to store user email addresses in the database?, just for the sake of the search...

---

In general I agree with others saying it's not worth the effort. However, I disagree that anyone who can access your database can probably also get your keys. That's certainly not true for SQL Injection, and may not be true for backup copies that are somehow lost or forgotten about. And I feel an email address is a personal detail, so I wouldn't care about spam but about the personal consequences when the addresses are revealed.

Of course, when you're afraid of SQL Injection then you should make sure such injection is prohibited. And backup copies should be encrypted themselves.

Still, for some online communities the members might definitely not want others to know that they are a member (like related to mental healthcare, financial help, medical and sexual advice, adult entertainment, politics, ...). In those cases, storing as few personal details as possible and encrypting those that are required (note that database-level encryption does not prevent the details from showing using SQL Injection), might not be such a bad idea. Again: treat an email address as such personal detail.

For many sites the above is probably not the case, and you should focus on prohibiting SELECT * FROM through SQL Injection, and making sure visitors cannot somehow get to someone else's personal profile or order information by changing the URL.