Is it safe to carry on using Dropbox? Yes and No: Part II

Ever since the news of a potential breach at Dropbox emerged, my old post “Is it safe to carry on using Dropbox?” has been getting an elevated number of hits. It is time perhaps to update.

Firstly, what’s this about a breach? Well, Dropbox wasn’t breached in the traditional sense of the word. The likelihood is that a number of Dropbox users had the same log-in credentials (email address and password) that they used on a different web account that was breached. The criminals were able to reuse the credentials stolen from elsewhere, and gain access to a number of Dropbox accounts.

Unfortunately, one of these accounts belonged to a Dropbox employee. The criminals gained access to his account and found a file containing an unknown number of users’ email addresses. It was probably these users that were subsequently spammed, leading to the suggestion that Dropbox had been hacked.

This leaves us two questions: is Dropbox safe to use; and what lessons should we learn?

Dropbox is no more nor less safe than it was before; that is, it is not safe. This for two reasons: firstly, it is in the cloud; and secondly, Dropbox is a US company. You don’t know what is happening in a cloud that is not your own; so it is not safe. Dropbox is registered in the US, and is subject to the PATRIOT Act – the US authorities are able to demand details of you and your account simply because they want them. So Dropbox is just not safe for confidential or incriminating content (and nor, note, is any other US-based cloud company).

But why worry if the data you store is neither of these? You can increase the level of security by locally encrypting the files (with something like TrueCrypt) and storing only encrypted files. The basic rule is simple: if it is important that nobody else ever sees the data, don’t use Dropbox; if it doesn’t matter if other people see your files, you can use Dropbox. If you’re somewhere in-between, encrypt.

What should we learn from this? Well, it is good that Dropbox has or will be initiating additional security – including two-factor authentication. This will make your data more safe from hackers, but it has no effect on law enforcement intrusion. And judging from Google’s 2FA, few people will bother using it.

I also very much like the new security page (partial screenshot below). It’s available at your Dropbox settings location, and shows who has recently accessed your account and who is currently accessing your account. This is certainly worth checking regularly. Note also that this is where you change your Dropbox password.

The new Dropbox security page

But despite this good response from Dropbox, the fact remains that these are reactive and not proactive steps. Security is still an afterthought, added on to systems rather than designed into them. That’s one lesson we don’t seem able to learn. Secondly, it is sad that a Dropbox employee should be guilty of fundamental security no-nos: he stored a file with user emails in plaintext; and he was reusing the same password on at least two different accounts.

These are the main lessons that we all need to learn: do not trust other people or systems to do security for you. It is your, not their, responsibility (or at least, even if it is their responsibility, you cannot assume they will do it).

And finally, and fundamentally, and beyond all others: when will we ever learn to stop re-using the same password on multiple accounts? Tens of millions of passwords have been stolen from tens of major providers this year alone – and that’s just the ones we know about. Are you sure that your own password is not included? If it is, and you re-use it on multiple accounts, then you simply don’t know who has access to your accounts. And if that includes your email account or bank account, not to put too fine a point on it, you’re screwed.

So, is Dropbox safe? Probably not; but that doesn’t mean we shouldn’t use it under certain circumstances. I shall certainly carry on using it. But are we safe? Absolutely not until we start using unique, strong passwords for every different account. Hint. Use a good password manager.

Update: the revelations from Edward Snowden concerning US government access to cloud services, which will include Dropbox, adds new urgency to considering the use of Dropbox. See our latest commentary following Edward Snowden’s Prism revelations: Is it safe to carry on using Dropbox (post Prism)? Yes and No: Part III

See also: Is it safe to carry on using Dropbox following the DMCA takedown revelations? (03/31/2014)

Is it safe to carry on using Dropbox with Condoleezza Rice on the Board? (04/14/2014)