Sign up ×
Information Security Stack Exchange is a question and answer site for information security professionals. It's 100% free, no registration required.

It certainly would be more convenient to store my KeePass database on either S3, Dropbox, or better yet SpiderOak. My fear is having my cloud storage account compromised then having the credentials recovered by either brute force or some other attack vector. How safe is this? What risks do I need to know about?

share|improve this question

8 Answers 8

up vote 7 down vote accepted

It is hard to quantify exactly, but if you have the DB on a mobile device then I wouldn't say this is particularly any less secure. KeePass encrypts the DB because the file remaining secure isn't expected to be a guarantee. It's certainly preferable that the DB file not get in the wild, but if your security depends on the encrypted file remaining confidential, then you have bigger problems than whether to use cloud storage or not.

A sufficiently strong master password should prevent brute forcing at least long enough for a breach to be detected and for you to change the passwords within it. In this way, it may even be slightly preferable to having a local copy on a mobile device as someone may compromise the file if you take your eyes off your device even momentarily and it would be much harder to identify that breach occurred.

Personally, I'd probably end up using my OwnCloud (which is self hosted), but I have the advantage of having my own personal web server and I realize that's not an option everyone can take advantage of. (The only reason I haven't is that I don't have a particular need to coordinate a key database in that manner.) Something public cloud based service should work as a fine second alternative though.

share|improve this answer
A VPS is worth having for just about every security-conscious person, IMHO. Vultr, DigitalOcean, et al start at $5/mo and you can load up a VPN, OwnCloud, etc on it. –  Arthur Kay Aug 20 at 20:09

I use the KeyPass-Dropbox combination. The password database is cryptographically protected using a key derived from a strong master password. Even if somebody acquires your encrypted password database through your cloud account, a strong enough master password renders brute-force attacks infeasible.

Simply put: Use a strong master password and stop worrying about this.

share|improve this answer

The cloud is inherently untrustworthy, and files kept on it should be considered vulnerable, so you need strong encryption to protect you. KeePass offers that. However, you then need to be able to trust every client you enter your password into. If you read them on an iPhone, do you trust the platform? Do you shield your password from the cameras on the subway when you enter it, every time? How about your laptop?

You also need to consider the value of what you're protecting. Is this safeguarding your retirement funds? Your fantasy bowling league scores? Political dissention that is illegal in your country? For some cases it's simply not worth the risk of making a mistake.

So yes, as long as you trust KeePass, and trust your devices, and trust your ability to keep your master key secured, don't worry about keeping the database in Dropbox.

share|improve this answer

Even if your KP database were to be compromised from Dropbox, using both a strong password, and additionally a keyfile not stored in Dropbox should give you security beyond any known means of electronic attack (as long as your devices aren't already compromised).

The keyfile should be stored in a separate secure location, such as a USB drive which you can secure physically. This provides 3 layers of protection:

  1. Dropbox account (assume low security)
  2. Your strong password (strong)
  3. Your keyfile (as secure as you make it)
share|improve this answer
Don't forget to have two or three USB keys with the encryption key on it. Preferably in separate, trusted locations. –  Arthur Kay Aug 20 at 20:07

You can increase the resiliency of your KeePass database to brute force by increasing the number of PBKDF2 iterations when deriving the database encryption key from your password. You can do this in KeePass under File > Database settings > Security. Personally, I use around 5,000,000 rounds (1 s delay). Remember that mobile devices are slower.

share|improve this answer
This is actually the best answer. In fact, what @Matrix suggests is crucial to secure a KeePass database. By default it is set to 6000 encryption rounds, which is insufficient to thwart a bruteforce attack. I don't understand why I'm the only one to upvote this answer. –  dr01 Jul 14 at 9:02

I am a strong believer in defense in depth on this.

No matter how strong your password is, it is also one that cannot be changed.

So to protect my Keepass DB, I am using three layers:

  • The database has a strong pass phrase (not just a password). I am not using a key file because, for me, the risk of losing the key file outweighs the security benefits.
  • The database is stored on an encrypted file system (I'm using encfs. By itself, it has of course been shown to be insecure, but it still adds a layer of protection).
  • The encrypted version is uploaded to an owncloud server, running on my own hardware, and of course over HTTPS.

On why the password cannot be changed: of course you can change the password, and it will actually re-encrypt the Keepass database, but you cannot retroactively change it on old copies.

Especially (but not only) if you store the database in the cloud, you have to assume that an adversary got a hold of the database at some earlier point in time, with an old password. That may give her the information she is after.

share|improve this answer

If you want to be really serious about things, run Boxcryptor in conjunction with Dropbox. Boxcryptor encrypts everything at your end PRIOR to sending to Dropboxs' servers. All that's at Dropboxs end is a load of encrypted stuff. Your keepass db ends up doubly encrypted!

share|improve this answer

If a group is able to compromise a cloud service enough to discover that you have a kdb to be cracked, they may have more motivation to plant a key logger/root kit on your personal devices. Of course, if such a group can see you downloading the software from sourceforge or an app store, they obtain similar information. In fact, this post is a much easier tip-off, so concern for this attack vector may be for individuals more paranoid than ourselves.

share|improve this answer
I'm not sure that this is an answer. –  schroeder Sep 20 '14 at 17:47

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.