Encrypted USB Flash Drive Question

Discussion in 'OS X El Capitan (10.11)' started by mac_in_tosh, Aug 5, 2017.

  1. mac_in_tosh macrumors regular

    mac_in_tosh

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    #1
    I am using one of these with my MacBook Pro running El Capitan. So when I insert it in the USB port it asks for a password.

    As my laptop is getting on in age, I am wondering what would happen if it suddenly went caput. Is the encryption password stored on the flash drive, so that I could use it on another Mac, or is it on the laptop's operating system (I don't use File Vault)? And if the former, would there be an issue should I upgrade to a new Mac running the current OS?

    Thank you.
     
  2. Fishrrman macrumors G4

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    Feb 20, 2009
    #2
    I'm thinking that the password for an encrypted flash drive "sticks with" the drive.
    Plug it into another Mac, enter the password, and it should mount.
     
  3. Weaselboy Moderator

    Weaselboy

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    #3
    You can plug that USB key in to any Mac and type in the PW and it will work. It is not tied to the original machine at all.
     
  4. mac_in_tosh thread starter macrumors regular

    mac_in_tosh

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  5. mac_in_tosh thread starter macrumors regular

    mac_in_tosh

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    #5
    That brings up a related question. If I create an encrypted disk image on my desktop (not on a USB flash drive), then where does the password reside - the OS or in the disk image file? I ask because I'm thinking of uploading a disk image to some cloud site like Dropbox as a remote backup of the sensitive information I have on the USB drive. If the password is with the disk image file, then I assume, in the event of my laptop failure, that I could download it on another Mac and open it (the only downside being that I'm also putting the password out there in the cloud, but hopefully that's not easy to break). If it's with the OS then it would do me no good to have the disk image in the cloud if my laptop fails.
     
  6. dsemf macrumors regular

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    #6
    When you encrypt a disk image, the password is the secret that is used to encrypt the image. The only way to decrypt the image is by using same password. The password does not reside in the encrypted image. It is no where except in your mind, unless you record it somewhere else. The effectiveness of the encryption will depend on the quality of the password.

    DS
     
  7. Weaselboy Moderator

    Weaselboy

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    #7
    It works much like the USB key. You could put that encrypted DMG anywhere you like, then open on another Mac later anywhere in the world and as long as you have the password, it will open. It is not tied to the OS.

    Now that said, it will optionally save the password to the Keychain application so you do not have to enter the password each time you attach the USB key to that Mac. But that does not tie the DMG or USB key to that Mac.
     
  8. mac_in_tosh thread starter macrumors regular

    mac_in_tosh

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    #8
    How can that be? The actual password must exist somewhere else in order to verify the password that you enter.

    So based on Weaselboy's input, my understanding is that the password resides with the disk image. I can move that disk image to some place like Dropbox to have an off-site location for the information it contains. As I update the information, I can simply replace the disk image in Dropbox with the new version. I can download the disk image on any Mac and open it as long as I have the password.

    I am usually extremely wary about putting any confidential information in "the cloud." But, realistically, I assume that by choosing a complex password the chances of someone breaking into the disk image are very low.
     

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