cross-platform archive encryption?

January 27, 2008 8:21 AM

Is there any way to encrypt an archive so that everyone (PC and Mac, maybe Linux) can open it without installing additional software?

I'm using a mac... I was using rar to create the archives but I guess some people with PCs couldn't figure out what to do with them. I could make an encrypted zip archive with stuffit, but i don't know if windows users can unzip it natively. Also, I guess mac users that don't have stuffit installed would be out of luck.

Basically I just want to share some documents online and restrict them to a certain group. I'd like to do it without using .htaccess as well.

posted by sero_venientibus_ossa to computers & internet (14 comments total)

I've had luck opening winzip encrypted archives on linux using wine; I bet that they work on mac, too.
posted by a robot made out of meat at 8:46 AM on January 27, 2008

Oh, also 7-zip is cross-platform. If people can't figure out a rar, who knows what they can figure out though.
posted by a robot made out of meat at 8:48 AM on January 27, 2008

What's annoying is that Stuffit supports encrypted zips, but the standard OS X file decrypter doesn't. So if you just double-click on one of these files on a clean install, it will show you an error screen.

It's still probably your best bet, since it looks like Windows supports it natively.
posted by smackfu at 8:58 AM on January 27, 2008

Archive manager in Ubuntu (a version of file roller) handles .zip and .rar archives with no problems, though they advise against using rar as a non-open format; I presume it's the same for most other modern Linux distros.
posted by Abiezer at 9:02 AM on January 27, 2008

If all you want to do is make sure that only select people have access to a file, encryption is probably not the best tool to use. I think it's important to say this for a couple of reasons. First, I think it's unlikely that you're going to find any kind of encryption that's fully cross-platform: the good stuff, like GNU Privacy Guard, doesn't come with Windows. Second, even if you do find something like password-protected ZIP files that everybody can handle, it may not be strong enough to keep snoopers out: a good password cracker could probably make quick work of them. Whether or not that matters to you is your call—only you can decide how important it is that the data not fall into the wrong hands.

I think you'll encounter a lot less hassle in the long term if you use software that's designed to authorize that so-and-so is allowed to allowed to access the file. It's not clear why you're avoiding .htaccess—maybe an NFS or Samba server would work better for you?
posted by brett at 9:17 AM on January 27, 2008

It seems like encrypted ZIPs don't encrypt the filenames, if that matters to you.
posted by smackfu at 9:18 AM on January 27, 2008

(Now that I think about it, Windows probably doesn't know how to talk to an NFS server, ruling out that option too... but at least there's still Samba!)
posted by brett at 9:54 AM on January 27, 2008

Thanks for all the info, looks like the answer is going to be no... Could anyone confirm that a winzip encrypted archive would open natively on mac? I figured it wouldn't.. like a stuffit encrypted zip.

As far as security and .htaccess- the files don't need to be uber secure so I'm not too worried about them being cracked. I don't really want to use any additional software unless it's something that everyone is likely to already have because basically nobody will figure it out. The documents are being shared amongst students and I'm in the process of moving everything from my server to the school's. I don't want to use .htaccess because some documents are not intended to be accessed by teachers.
posted by sero_venientibus_ossa at 10:02 AM on January 27, 2008

I can confirm that Windows XP has native support for encrypted zip files.
posted by gmarceau at 12:30 PM on January 27, 2008

Encrypted RAR can be opened on either platform, in my experience.

RAR encrypts the filenames where ZIP (Winzip or other) doesn't. But whether your target audience has RAR on their computer is another matter.

ZIP and RAR are platform-independent; it's only the app that implements the packaging that's OS-specific (I think.)
posted by anadem at 6:22 PM on January 27, 2008

("...either platform" = Windows + OS X; sorry, don't know about Linux.)
posted by anadem at 6:23 PM on January 27, 2008

encrypted rar files work fine under linux. Like zips, the filenames do not get encrypted.
posted by jjb at 6:46 PM on January 27, 2008

I don't want to use .htaccess because some documents are not intended to be accessed by teachers.

Is there any reason to think that the teachers have full filesystem access to the web server? Why wouldn't you just use .htaccess and not give the teachers user/password pairs in the password file? If your files on the server have permissions such that only you and the web server process can read them, .htaccess should be plenty.

Unless you're in the US, and by "documents" you mean "movies and music", in which case the IT staff might eventually notice and ask you to knock it off. If that's what you're concerned about, leaving them on your server is the way to go.
posted by hades at 11:14 PM on January 27, 2008

Throwing out some different ideas here...

How big are these files? How about opening up an email account at gmail, uploading the files as attachments, and giving out the password to just the people you want? Or you could try something with Amazon's S3.
posted by philomathoholic at 12:01 AM on January 28, 2008