EncFs insecure, what to use now

Question

I love encfs as it provides file-based encrypting which is quite useful when it comes to cloud storage. But it looks like that especially for this use case, encfs is considered to be insecure. I'm aware that encfs 2 is in development but how to deal with it in the meantime? Are there any alternatives that integrate well in ubuntu?

Edit: The security issue I mostly refer to is this one. It is still present in version 1.8 and makes your files vulnerable if someone get's multiple versions of your encrypted files. If one is worried about services like Dropbox are not that thrustworthy and encrypts folders uploaded into the cloud because of that, the opportunity that the attacker (the service) gets more than one copy of the cyphertext is absolutely given.

Answer 1

The conclusion in the link sums it up:

4. Conclusion

In conclusion, while EncFS is a useful tool, it ignores many standard best-practices in cryptography. This is most likely due to it's old age (originally developed before 2005), however, it is still being used today, and needs to be updated.

The EncFS author says that a 2.0 version is being developed 1. This would be a good time to fix the old problems.

EncFS is probably safe as long as the adversary only gets one copy of the ciphertext and nothing more. EncFS is not safe if the adversary has the opportunity to see two or more snapshots of the ciphertext at different times. EncFS attempts to protect files from malicious modification, but there are serious problems with this feature.

So the question you need to answer: How likely is it that an attacker can get hold of the ciphertext?

---

But that audit is from 2014 and was done on v1.7. v1.8 already fixes some of the issues mentioned in the audit:

The first EncFS 1.8 release candidate fixes two of the potential vulnerabilities mentioned in the security audit and brings a few other improvements:

• improve automatic test converage: also test reverse mode (make test)
• add per-file IVs based on the inode number to reverse mode to improve security
• add automatic benchmark (make benchmark)
• compare MAC in constant time
• add --nocache option

v1.8 came out in 2014 too.

---

From the project page:

Status

Over the last 10 years, a number of good alternatives have grown up. Computing power has increased to the point where it is reasonable to encrypt the entire filesystem of personal computers (and even mobile phones!). On Linux, ecryptfs provides a nice dynamically mountable encrypted home directory, and is well integrated in distributions I use, such as Ubuntu.

EncFS has been dormant for a while. I've started cleaning up in order to try and provide a better base for a version 2, but whether EncFS flowers again depends upon community interest. In order to make it easier for anyone to contribute, it is moving a new home on Github. So if you're interested in EncFS, please dive in!

That is from 2013... I would consider the project dead if that was the latest news.

But it does list ecryptfs as an alternative for Ubuntu so have a look at that.

Answer 2

As I write this, there seem to be quite a few open source tools similar to encfs (but more "modern" than encfs) that could be able to encrypt files in a "cloud friendly" way (i.e. providing per-file encrytion, keeping modification times, and so on).

Most of them are fine if you are using only Ubuntu or any other Linux system (ecryptfs seems good), but things become difficult if you require interoperability with other OSes and mobile devices, as most of us is expecting nowadays.

Just to name a few:

• Cryptomator seems to be the only one that works "everywhere", from any GNU/Linux OS to Android. There's even a PPA for Ubuntu and binaries for several other distros and OSes.
• ecryptfs works only on GNU/Linux systems (like Ubuntu, but also ChromeOS), and it's nice if you won't need to access your files from non-Linux OSes, but people say there may be some problems with cloud sync tools.
• CryFS it's a young solution, works only on Linux for now, but there are plans to port it to MacOS and Windows also. Maybe it worths some attention in the future.

You may find also interesting this comparison of tools from the CryFS website: https://www.cryfs.org/comparison

Answer 3

Encfs is invaluable because of its reverse feature. This instantly makes off-site, semi-secure incremental backups possible, with no additional disk space cost.

Truecrypt doens't have this, nor Veracrypt, nor ecryptfs.

While encfs 2.0 is being worked on, check out https://www.cryfs.org/, which isn't 1.0 yet. Another possibility is https://github.com/thkala/fuseflt which lets you create filtered views of directories (e.g. an encrypted view using flt_cmd = gpg --encrypt).