Zip file encryption not working as expected

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rg1
Posts: 2
Joined: Wed Mar 28, 2012 1:30 pm

Zip file encryption not working as expected

Post by rg1 » Wed Mar 28, 2012 1:40 pm

With an eye to storing my backup zip files in the cloud, I decided that I would like to encrypt them. So I went to the Compression page in Backup Properties, and changed the setting from "No encryption" to "Strong encryption (AES), with the default 128 bit selected. I also set the password.

I did this in several backups, on three different computers. Overnight, 5 of them ran and for all 5 new incremental *.zip files were created. I was expecting that I would not be able to open these zip files directly (i.e., by opening them in WIndows Explorer), but that was not the case. Four of the five opened as usual, and I was able to view the files in each archive without ever having to provide the encryption password. One of the 5 behaved a bit different, I could not open it but only because I got a "The Compressed (zipped) Folder is invalid or corrupted." message, and not a password prompt.

So, what's going on? Why were these incremental zip files not encrypted? I have confirmed that the settings in the Compression page are still set to Strong encryption.

Anyone seen this before?

Thanks in advance for any help you might be able to provide.
-Rob

Support
Posts: 1475
Joined: Wed Dec 16, 2009 12:46 pm
Location: Cluj-Napoca, Romania
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Re: Zip file encryption not working as expected

Post by Support » Fri Mar 30, 2012 12:20 pm

Hi,

Were you able to see the file name or the file content?
Please note the encryption will protect the file content (you won't be able to open the file without the password) but it won't encrypt the file names.

rg1
Posts: 2
Joined: Wed Mar 28, 2012 1:30 pm

Re: Zip file encryption not working as expected

Post by rg1 » Sat Mar 31, 2012 1:13 pm

You're right, that's it. I did not actually try to open a file. When I do, nothing happens - there is no prompt for an encryption password - but that is satisfactory for my purposes.

Thank you very much!

-Rob

sierra
Posts: 3
Joined: Mon May 13, 2013 12:12 pm

Re: Zip file encryption not working as expected

Post by sierra » Mon May 13, 2013 12:34 pm

Hi,

On the other hand I think that being able to view file content of encrypted archives should be avoided by all means.
This is not what we naturally expect from strong encryption.

From what I understand it is related to the ZIP archive format:
http://kb.winzip.com/kb/entry/147/

7z archive format (and others maybe?) allows to encrypt everything (file name and data).

May I suggest to implement file name encryption in order to improve security and privacy?

Thank you!

Support
Posts: 1475
Joined: Wed Dec 16, 2009 12:46 pm
Location: Cluj-Napoca, Romania
Contact:

Re: Zip file encryption not working as expected

Post by Support » Wed May 15, 2013 7:51 am

Hi,

We are working to implement such a feature in the next version of Backup4all.

sierra
Posts: 3
Joined: Mon May 13, 2013 12:12 pm

Re: Zip file encryption not working as expected

Post by sierra » Wed May 15, 2013 12:54 pm

Hello,

If you are already working on it, that's a very good news.

Keep up the good work on B4A!

Cheers

sierra
Posts: 3
Joined: Mon May 13, 2013 12:12 pm

Re: Zip file encryption not working as expected

Post by sierra » Sat Jan 11, 2014 3:44 pm

Thanks for the implementation in V. 5.
It's very appreciated!
Cheers.

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