Confidentiality of filename and metadata

[MeanMangosteen]

The filename and a file's metadata (size, date modified, permission) should be encrypted. This is because these entities can leak information about the file, which is meant to be secret, even though the file content is encrypted.

I think to start with, just the filename can be encrypted, we can deal with encrypted metadata after.

Both CryFS and EncFS encrypt filenames, however, only CryFS encrypts metadata aswell. It needs to be revisited on how they accomplish this.

[MeanMangosteen]

VeraCrypt encrypts both filename and metadata too.
https://github.com/veracrypt/VeraCrypt.

[CMCDragonkai]

We can revisit metadata encryption later. Hopefully no path dependency.

…

On 6 March 2019 14:49:52 GMT+11:00, ll-aashwin-ll ***@***.***> wrote: The filename and a file's metadata (size, date modified, permission) should be encrypted. This is because these entities can leak information about the file, which is meant to be secret, even though the file content is encrypted. I think to start with, just the filename can be encrypted, we can deal with encrypted metadata after. Both CryFS and EncFS encrypt filenames, however, only CryFS encrypts metadata aswell. It needs to be revisited on how they accomplish this. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: #6

-- Sent from my Android device with K-9 Mail. Please excuse my brevity.

[CMCDragonkai]

This is addressed in #8? If so, we can close this.

[robert-cronin]

One way to implement encrypted file structure would be to encrypt the directory
and file names in the lowerfs so that at each level in the heirachy, EFS will
have to decrypt in order to continue its traversal. This would mean O(n) on
every directory traversal.

Another way would be to store the entire directory listing as a unit of plaintext
that gets decrypted into ciphertext. This requires the directory listing to be
consistent. This comes with some possible errors, e.g. it will fail if the
underlying folder structure changes.

[robert-cronin]

Closing on account of migration to gitlab