Encrypted folders and files stay encrypted when copied

I just tried out Windows 7 feature to encrypt a folder. I found that when I access the encrypted folder from another computer (the parent folder of the encrypted folder is shared) I can see the files there but I could not open it (which is good). But when I copy the file to another folder outside the encrypted folder (regardless it is on the same remote computer or to the computer from where I am accessing the files) then I can open the file without any problem. This might be how it works ... but that's not what I need.

My question is: Can I encrypt a folder (and all files inside), access those files (create, edit) seamlessly while I am logged in normally to the computer ... but make the files stays encrypted when they were copied to another directory outside the encrypted folder? Regardless they were copied to the same computer or another computer or uploaded to a remote server.

If this is not a feature that Windows natively support, is there third party software that does that?

Thank you.

user66126

Posted 2011-02-04T20:51:18.500

Reputation: 21

2You want the files to remain encrypted even though they're not in an encrypted container? Really? – Ignacio Vazquez-Abrams – 2011-02-04T20:53:00.377

@Ignacio Vazquez-Abrams: pretty much, yes. Is that not a common practice or it is simply technically impossible? – user66126 – 2011-02-04T21:17:37.340

Impossible. The only option would be creating a TrueCrypt container, and carry it anywhere you like. I mean, what, you want Windows or another OS to simply recognize it as encrypted without any additional application? No just no. There are no standardized encryption application across OS, and your current encryption, EFS I believe, won't work on non-NTFS partition (such as your average flashdrive and most non-Windows system) – Martheen Cahya Paulo – 2011-02-05T04:50:45.467

Answers

I believe you would have to set the encryption on the file level not the folder level for this to function as you want it to. I have not tested this so I do not know for sure. Generally I do not like answering without testing first but I am answering with a suggestion. You should definitely consider Truecrypt, it's free, open source, easy to use, and has a great community.

Supercereal

Posted 2011-02-04T20:51:18.500

Reputation: 8 643

Hi Kyle, thank you for your response. My understanding of how Truecrypt works is: we create an encrypted file, for example 1GB in size, and then mount the file as a volume. Then we can access the volume just as we access folder. But when we copy a file from that volume to another folder it will be decrypted automatically? I might understand it incorrectly? – user66126 – 2011-02-04T21:11:42.867

@user66126 correct, once you take the file out of the container it will no longer be encrypted. – Supercereal – 2011-02-04T21:14:04.067

Reading this post: http://superuser.com/questions/188119/how-to-remove-encrypted-flag-when-copying-a-file-from-a-hdd-to-a-usb-drive

it sounds like copying the file should not decrypt it?

– user66126 – 2011-02-04T21:18:21.660

1@user66126 that person was using encryption on the file level like I mentioned in my answer... – Supercereal – 2011-02-04T21:20:16.213

You could also try and secure the file by going into the properties of the file and editing who has rights to view/change it.

w7pro

Posted 2011-02-04T20:51:18.500

Reputation: 692

Danger! While that will prevent unauthorized logged-on users from reading the file, an attacker with physical access to the system (or administrator-level access to the OS) can read any such file. – Ben N – 2015-12-28T22:26:37.057

You can permanently encrypt individual files using a file encryption utility (such as axcrypt). The file will stay encrypted regardless of where it is copied or move to.

Using Windows built-in encryption (EFS), once a file is encrypted by EFS in Windows, it should stay encrypted when copied or moved around in the same NTFS file system on the same computer. (According to this TechNet article, ):

If you copy or move an unencrypted file (or folder not marked for encryption) into a folder that is marked for encryption, that file (or all of the files in that folder) will become encrypted. Once encrypted, files will remain so no matter where you move them within the local file system—whether to folders not marked for encryption or to completely different partitions. The individual files themselves are not automatically decrypted. However, if a user has the permission to decrypt a file, and that user copies or moves an encrypted file to a file allocation table (FAT) or FAT32 partition, the destination file will be unencrypted.

MoonDogg

Posted 2011-02-04T20:51:18.500

Reputation: 51

The issue you are having is with inheritance. When you encrypted the folder, its contents - including the file - were encrypted. However, when you move the file out of the encrypted folder, it is no longer inheriting encryption.

If you want a file to always be encrypted, you need to encrypt the individual file, not the folder.

Keltari

Posted 2011-02-04T20:51:18.500

Reputation: 57 019