Cross-platform encrypted disk-image formats?

Is it possible to create an equivalent of an encrypted disk-image in a format that is readable under Windows? I am able to create a .dmg file using Disk Utility in MacOS and define the file-system as DOS, and encrypt it, but .dmg files are not readable under Windows. Some Win utilities claim to be able to read these, but I have not found any that work.
Is there a standard solution for creating a disk-image on my Mac that is not Mac-specific? I want to create an encrypted DOS/FAT file-system disk-image, store files in it, then open it under Windows. Does such a solution exist?
Thanks,
--- Christer

Does TrueCrypt do what you want?
(55088)

Similar Messages

Unable to create an encrypted disk image in Lion

disk utility gives the error Unable to create "Volume.dmg." (error - 60008) when creating an encrypted disk image. I am using the following steps:
    1.    Open disk utility
    2.    Select the disk (internal or external) to create the image on
    3.    Select File>New>Blank Disk Image…
    4.    Save As: 'Volume'
    5.    Name: Volume
    6.    Size: 50GB
    7.    Format: Mac OS Extended (Journaled)
    8.    Encryption: 128-bit AES encryption
    9.    Image Format: read/write disk image
    10.    Click the Create button
    11.    Password dialog appears
    12.    When I enter a password the dialog closes after entering only a few characters i.e. before I've finished typing, and the following error message displays:
Unable to create "Volume.dmg." (error - 60008)
I have previously, successfully, created encrypted disk images in Snow Leopard, and I don't know why I can't in Lion
Does anyone have any ideas?

Thanks for this Thomas.
I've tried naming the image differently, but still received the error, I did however try different permutations for the password.
The error seems to happen if I use a purely numerical password string and occurs on input of the 10th numerical character, if I start with numerical character but use an alpha before the 9th number I can continue and create a password, and I can create a password if I start with an alpha and switch to numerals after the first alpha character, purely alphabetical passwords are fine too.
It seems that Lion doesn't like purely numerical passwords greater than 9 characters, whereas Snow Leopard wasn't so fussy. Seems it's a bit of a bug.
Thanks for your help

Unable to create an encrypted disk image with Disk Utility

Hi:
With our upgrade to Lion a few weeks ago, we're now unable to create an encrypted disk image of any type using Disk Utility any more. This problem occurs on 3 different machines, and is reproducible whether one is using an internal HD or an external FW HD. We can successfully create nonencrypted disk images.
This is a duplicate post with all the details here: https://discussions.apple.com/message/18469359#18469359
We haven't had any luck with a solution trying various permissions fixes as helpfully suggested by other readers in response to the error message # (-60008 error), so I'm hoping that someone else has run across a solution from the encrypted disk image perspective and that this tag line will generate some help.
Thank you!

Save As: 01 (on Desktop)
Name: 01
Size: 100 MB
Format: Mac OS Encrypted (Journaled)
Encryption: 256-bit AES
Partitions: Single partition- Apple Partition Map
Image Format: read/write disk image
At the password window that pops up I enter: 1234567890
This says password strength is "Weak"
All works fine
Then I repeated this using:
Save As: 02 (on Desktop)
Name: 02
Size: 100 MB
Format: Mac OS Encypted (Journaled)
Encryption: 256-bit AES
Partitions: Single partition- Apple Partition Map
Image Format: read/write disk image
At the password window that pops up I enter: 1234567890 and when I start to enter the next "1" I get the "Unable to create "02.dmg." (error -60008)
OS 10.7.4
Disk Utility Version 12.1.1 (353)

Encrypted Disk Image to Password Protect Folder Not Working!

I have followed the instructions exactly for creating a Disk Image in order to password protect a folder. Folder contains multiple types of files including images, pdfs, etc. Here is what I've done and what happens:
In Disk Utility I created a New Disk Image from Folder. I chose the folder, which I have on my Desktop, and clicked Image. I gave the Disk Image a new name, placed in on my Desktop, indicated the image format as read/write and chose the 128-bit encryption. I chose a very strong password and unchecked the remember password box. At this point, all seems to have gone well.
Now, back to my Desktop. I have two things going on.
1. The initial folder that I wanted password protected is still present. Am I supposed to just send this to the Trash?
2. When I double click on the the new .dmg file that I've created, I am asked for my password, which I put in. Then, nothing. I mean, nothing happens. It doesn't open, it doesn't do anything. I can click on it and choose Open with DickImageMounter, and nothing happens. I can open with Disk Utility, but this just gives me the normal options to eject, burn, restore, etc.
I don't know why I can't get this to work properly, and I'm a little annoyed that Apple can't make it as simple as selecting a folder and having the option to password protect it, just like you can a normal file. PLEASE HELP!
Thanks.

As of OS X 10.7.4, Disk Utility had a bug that prevented it from creating an encrypted disk image with a password of more than 10 characters. I haven't checked recently to see whether that bug has been fixed, but from your report it seems not to have been. There is a workaround, but it's complicated.

Creating a LARGE Encrypted Disk Image

Hello,
I have to encrypt a LARGE external Hard Drive for my work (a 1 Terabyte external drive, which comes to about 930 gigs to encrypt).
I have to do one of the regular encrypted disk images, not one of those expandable ones.
I know that encrypted disk images take a long time to create, as I’ve created smaller ones in the past and they take hours.
Does anyone know how long it will take to create an encrypted disk image of this size?
AND, since it will probably take quite a while, I was wondering if it is BAD for my MacBook Pro or the external drive itself to write information for this long of a period. I just want to make sure I don’t damage anything.
Thanks for any help.

I did a 400 GB one and it must have taken an hour to get the password prompt, a couple more for the creation, and another for formatting and mounting.
If you have a bed and sleep daily, as I suspect you do, start an hour before bed, enter the password and it should be done by morning.
You don't need a 900 GB image unless you have one 900 GB file which I doubt. Make one smaller one say 300, then copy it twice. The password will be the same in all 3 copies.
If you look at activity monitor not much is going on during all this so don't think the house will burn down (or your pants - see other question posted today).

Any gotchas for encrypted disk images?

I am about to set up e-bills and e-statements at various banks and credit cards and wanted to check a couple of things before doing something that may end up being bad
The assumption I am going with, is I will create an encrypted disk image to store all the PDF's.
1. Is that the right thing to do? Or is there a better way to keep the data secure?
2. If I do so, what is the backup impact? Can I simply set up a task to copy and paste the entire disk image to my external drive?
3. If I want to open the disk image on another computer, can I? How will it authenticate the user/pass on a different computer?
4. I can backup an encrypted disk image to a FAT-formatted external drive?
5. And finally, I have read disclaimers that if I forget the password the data is lost irretrievably. But also, that the password is stored in keychain. So if the password is stored in keychain, the worst-case scenario can only happen if I forget the master password, right? I don't need to truly remember the password to the disk image necessarily, right?

baltwo wrote:
Your profile info indicates that you're running Tiger. If so, post to those forums. If you're running Leopard, update your profile info. What are you trying to protect and from who? Is your computer secure?
IIRC, encrypted disk image passwords are independent from Keychain Access. So if you forget it, then you're hosed. BTW, that's the major failing with encrypted anything. If you forget the password, you're hosed. If the disk image gets corrupted, it's useless with or without the password. Anything stored in an encrypted disk image needs to be backed up in an unencrypted state and stored in some kind of physical thing like a safe. Methinks your a bit paranoid. Disable auto-login, use high-level passwords (that you remember), don't enable the root user account or activate a master password, and you should be secured enough.
I updated the profile. I am running Leopard. So this is the correct forum.
What am I trying to protect? I thought I put it in the first line - statements from banks and credit cards.
From whom? From unwanted entities who may get access to my computer, in any way.
I didn't get the part about the safe. Can I or can I not back up an encrypted disk image to an external drive "as is"? What about possibly opening it up on another computer? And how about putting it on a FAT-formatted disk? I repeat my original questions, but for a reason - they seem to have not been answered.
I do not have auto-login, and I remember my strong login password. I don't have my root account enabled. Under this scenario you think my data is going to be secure? What about if someone were to get control of my computer? Forgive me on this one, I am a switcher so there is a general paranoia about such things which I would like to clarify before reorganizing my life.

Making encrypted disk image takes hours?!

Before I made a Time Machine backup, I wanted to use Disk Utility to create an encrypted disk image on an external hard drive. This way, my computer backup is password protected.
So I set the file for 200G at 128 bit encryption.
That was 12 hours ago. According to the progress bar, Disk Utility is still only one-quarter done with creating the disk image.
Is it normal for Disk Utility to take a full day (possibly two) to create a disk image of this size? Is there any way to create a password-protected disk image quicker? (And, for what it's worth, the external drive is formatted for Mac OS Extended, Journaled.)
Thanks for any advice on this...

Hi, and welcome to the forums.
I'm not quite sure just what you're trying to do.
Are you planning to have Time Machine back-up to that encrypted disk image? If so, that's not going to work. When you start Time Machine, it will create a Backups.backupdb folder on whatever drive or partition you select, then place it's backups in that folder, not in a disk image.
If you want to encrypt your whole home folder, you can use File Vault (System Preferences > Security > File Vault). That will encrypt your entire home folder. But that's almost certainly vast overkill, and has many complications of it's own. Read up on it thoroughly before deciding to do it.
If you have a few files that you want to encrypt, create a (smaller) encrypted disk image on your internal HD, in your home folder. Then copy the documents into it, and securely-delete the originals.
Then TM can back-up your entire system "as is" -- without the overhead of encrypting OSX, your apps, configuration, and everything else in your home folder, but the disk image (and it's backup copy) will still be encrypted.

Can't paste password for new encrypted disk image.

Howdy all!
I have been trying to create an encrypted disk image with the Disk Utility, but I'm having trouble with putting in the password.
Using the password assistant, it only fills one of the two password fields, and I cannot copy/paste the password to the other field. If I generate a password elsewhere I cannot paste it into either box as well.
If I switch applications from Disk Utility and come back to the password dialog the menubar says I am still in whatever application I was last (in this case it says Firefox at the very left) and the Edit menu is completely grayed out.
Any idea how to get a non-typeable password into this dialog?
Thanks for your help.
Mike

You can paste it in if you use hdiutil to create or mount the disk image (In Terminal.app). That's the
only way to go if you use a "bullet proof monster" password like I do.
To create an encrypted, sparse disk image, open a Terminal window and cd to the directory in which
you want to create the image file. For example:
cd ~/Desktop
Then type the command:
hdiutil create -size thesize -encryption -type SPARSE -fs HFS+ thename
live command example:
hdiutil create -size 1g -encryption -type SPARSE -fs HFS+ myimage
(this will create a 1gigabyte sparse image with the hfs format with the name "myimage.sparseimage"
#note: I love sparseimages and sparsebundles because they mount so quickly#
Above, the size is the maximum size that the volume will ever be able to contain, for example,
660m for 660 megabytes or 1g for one gigabyte. Note that if you want the image file to remain
below a certain size (such as the size of a CD) you must allow for approximately 10% overhead.
Also above, thename is the name of the image file you want to create, not the volume name.
The volume name will be "untitled". Rename as you would any other mounted volume (after it is
mounted).
You will be asked for a password or phase to secure your file. In terminal you may copy and paste
or use command + V keyboard combo. It will mount normally after that.
I don't use the "Remember password (add to Keychain)" function because my passphrase will be
visible in the Keychain to anyone with physical access to your computer.
Instead I use Terminal to open my new image.
Open terminal.app, simply type:
hdiutil attach /path/to/imagefile
example:
hdiutil attach /Users/kj/Desktop/myimage.sparseimage
(remember, you can drag and drop the file path into the terminal from Finder)
Terminal will ask for your password, simply cut and paste from your favorite password program
(such as "1Password").
There is a manual page available; type man hdiutil in the Terminal.
Enjoy,
Kj

Encrypted Disk Image on TC?

Can anyone check for me whether Time Machine will backup to an encrypted disk image on Time Capsule?

The Time Capsule doesn't show up one the left side of the screen in disk utility. When you click the "new image" icon on the top of the screen in disk utility a menu pops up, there should be a down arrow button next to the top line that says "save as", click that down arrow button. The middle part of the popup menu should expand. To the left on the expanded part your time capsule should be listed under "shared". Select your time capsule, and then click the arrow button again next to the "save as" line. Your time capsule should now be shown on the second line that says "Where". Now pick what you want to call the disk image and type it in the "save as box". In the other pull down lines you can pick how big and what format to make the image. Then click "create" and that should do it. Does that make sense to you?

Encrypted disk image from ****

So i made an encrypted disk image and forgot the password.
The disk image:
Size: 100 mb
Format: Mac OS X Extended (Journaled)
Encryption: 25-bit AES
Partition: Single partition-Apple partition map
..and no, i didnt save the password on my keychain
...(you can stop laughing now :P )
I´ve been in contact with Apple Care and we spent about 3 hours trying loads of things with no luck.
I know im more or less f*ed, but i know there is a lot of smart ppl on this forum.
If anyone has idea, no matter how crazy, im willing to try it.

Hi Worm76;
My suggestion is forget about what was in the encrypted disk image. Write it off as lost.
It would take someone like the NSA to get it back for you and I doubt very much that you have anything in there to interest them.
Allan

DIsk Utility, encrypted disk image

I cannot create an encrypted disk image. I have searched through the discussion forums here but have not found an answer. After I select the name, location, image format, encryption and I hit save, I get an error that says "Unable to create '[file name].dmg'. (Resource busy)". I've tried different locations, image format and encryption, but I keep getting the same message. Any ideas what the problem is and how I can fix it? Thanks.
NB: I want to create the disk image so that I can encrypt a few files with sensitive information. I do not want to use filevault, as I understand that it has downsides (e.g., free space needed to turn on and off, and backup with TM).

1. Open the Disk Utility application. (If you don't know where it is, search for it in the spotlight.)
2. At the top of the Disk Utility window, you will see several icons. Click on the one labeled "New Image". Before you do this, make sure that none of the drives on the left column (including "Macintosh HD") are selected.
3. A new window opens. It asks you for the name you want to give the new disk, and where you want to save it to (you can choose to save it on the desktop). It will also ask you for the volume size of the new disk (the default setting is 100MB, but you can give it any size you want). It also asks you for the volume format, encryption (128- or 256-bit; 128 should be enough, unless you want to make it more secure, but compromise a bit of speed), partition (there is no need to partition; in fact, many recommend no partition at all), and image format (if you plan to frequently add and delete files on your encrypted disk, "sparse bundle disk image" is recommended".
4. Click "create". It will ask you to create a password for your disk image.
5. The new disk image should appear on your desktop (or other destination you chose). Double-click on the image to open it. It will ask you for your password. Enter the password you selected. You can choose to save the password on your keychain. That defeats the purpose of encrypting the disk image, since anyone who gains access to your computer will not have to enter the password to open the disk image and see its contents.
I hope this step-by-step guide helps you. Let me know if something is not clear or if I got something wrong.

Problem creating encrypted disk image

I have just moved from an Aluminium PB G4 with 10.3.9, on which I successfully created encrypted disk images and sparse images.
I now want to do the same on a brand new WD My Book attached to the new Macbook Pro. I open Disk Utility and click New Image. But when I do so, there are fewer options than there are on the old machine. I only have
Save As
Where
Image Format
Encryption
No option for specifying size, no sparse option.
Also, if I try and create a dmg on the My Book, I get 'Unable to create "myfilename.dmg". (Invalid argument)'
Any suggestions? Thanks

V.K.'s suggestion worked. Thank you. But now I've found that I get the full set of options in Disk Utility too. Baffled.
In the week I've been using my new Macbook Pro, I seem to be getting eerily similar experiences, i.e. apps don't work right, then I quit and next time they behave themselves. Yes, I know it sounds weird.
Is this an appropriate place for me to ask further questions. Namely, what's the best place to find out about 1. read/write v. sparse disk v. sparse bundle? 2. partitions - should I used them, whatever they are? and 3. why are the bigger disk images called CDs and DVDs? If I want a passworded place to put files on my external drive, bigger than 500MB, is there any reason not to use one of the CD/DVD size options?
Thanks

Does it work with encrypted disk images?

Hallo,
I have a 10 GB fixed size image on my account and it is encrypted. It uses about 4,8 GB on the disk.
I would like to know if time machine is able to detect when changes are made inside such disk image,
if yes, if it is able to add just modified data or if it will copy all 4,8 GB file every time backup is made.
Thanks

If it is a standard encrypted disk image, Time Machine will copy the whole 4.8 GB every time.
But you can convert your disk image to a "SparseBundle" with this Terminal command:
hdiutil convert -format UDSB -imagekey sparse-band-size=32768 -encryption -o ~/Desktop/newimagename /path/to/olddisk_imagename (make sure that is all on one line)
That will copy your old disk image to a new one on the Desktop. A sparsebundle looks and behaves the same way as a regular .dmg. But the sparsebundle is actually a package that contains all of its data in 16MB bands. With any luck, your data changes will clump together in a few of these bands, and Time Machine will copy only those bands over rather than the whole shebang.

Encrypted disk image on external drive prevents that drive from ejecting

I've tested this a few different ways, and it seems to be a rather consistent problem.
I have an external USB hard drive (seagate) and on that drive I use encrypted disk images to store my data.
(because it's a portable drive, I'm nervous I'll lose it and then someone will have access to my stuff).
So anyway, whenever I mount the sparse bundle disk image, when it comes time to eject the drive (after ejecting the disk image of course), it hangs for a while and then the Finder says it can't eject, but that I can Force Eject the drive. When I chose to Force Eject, it works, but I don't like having to force it every time.
Anyone know what's up?
Thanks,
Brian.,

Open Disk Utility > File > New >Blank Disk Image...
or use the "Option-⌘-N" Key combo (with Disk Utlity open).
Kj

Create encrypted disk image with OS install disk utility.

I thought to make a full backup of Macintosh HD, and followed instructions in /kb/ht1553. However, every time I tried to creae an encrypted disk image, it barfed with "Failed - User interaction required". I assume it needed the encryption password, but for some reason was unable to display a prompt for this. Anyone know how to fix this? Thanks, Stephen.

Create an encrypted sparse disk image instead of from folder, mount it, and then drag & drop your files into ii.

Cross-platform encrypted disk-image formats?

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