MacMost Now 716: Encrypting USB Flash Drives

If you carry around USB flash drives, you may want to consider password protecting them in case they are lost or stolen. It is easy to format a drive with encryption using the OS X Disk Utility app.

Video Transcript
Hi, this is Gary at MacMost Now. On today's episode let me show you how to create password protected encrypted flash drives that work with Mac OS 10.

So suppose you have very important sensitive files that you want to carry with you but you are worried that if you loose it or it gets stolen that somebody will get access to these files. You can encrypt each one of these with a password so that only you with your password can get the data on them. Then you can carry them around secure knowing that if you loose it that nobody can get access to the data.

The key to doing that is how you create the drive, how you erase and format it. You are going to do that by using disk utilities. Run disk utilities and find that drive, and I've got it plugged in here. I have a 1 GB drive and it has nothing on it now and it is untitled. I am going to select the drive here and select erase and when I choose format I can choose say a windows based format or a Mac format like this and that's how I would normally format it as Mac OS Extended.

I can also choose Mac OS Extended (Journaled, Encrypted) and that's what I am going to do. Let me give it a name and then I am going to hit the erase button. Now what is going to happen is that I am going to get prompted to enter in a password so I am going to do something very simple and secure here and verify it. It is going to tell me that the password strength is very weak so I am going to add a couple of numbers to it to strengthen it a bit. I am going to give myself a "Hint" which is very useful. If you forget this password then you are just like anyone who has found this drive with no way to get into this stuff, so you want to make sure this is a password you can remember. Maybe write is down and put it in a drawer at home or use it in a secured thing like one password allows you to secure passwords securely or give yourself a good hint to tip you off and it won't give anyone else access to the information there. Then you hit erase and it will format the drive. It will be encrypted and the only way you can get access to it is if you have that password.

So what happens when you plug that drive into another Mac. Well, you can see right here I have plugged it in after ejecting it and it asked me for the password. If I don't have the password I can't get into it. Let's enter something random to unlock and you see it is not going to let me in. I'm going to use the password and I can select to have it remember this in my keychain. This could be useful. You can have it remember it in the keychain of your main Mac so this drive is always easy to get to on your Mac but then when you insert it into someone else's Mac it won't have the password stored in the keychain and you would have to enter it in. Once you unlock it you have it available now on other devices and you can add files to it as with any normal drive.

So it is important to know the distinction between simply password protecting something and password protecting and encrypting it. When it is encrypted that means the contents of the drive is completely encrypted and you can't actually look at the bytes on there and figure out what is on the drive. You need the password to decrypt what is on there. That means when it is merely password protected it simply means that the stuff is there and if you get past the password barrier you can get to the files. So you can basically break into the drive. That is not how this works at all. An encrypted file means it is very safe. It is important that you use a strong password, something like a dictionary word or your birth date or your son's name is not going to be strong enough to stop people from getting into it.

The big disadvantage to this of course is that it is Mac OS formatted which only means it will only work in other Macs and actually may require a recent version of Mac OS 10. It certainly works in mine but I am not sure how far back in Mac OS 10 an encrypted USB drive like this would work.

I hope you found this useful. I know I encrypted all of my USB drives whether it contains something important or not. It is just nice to know that if I loose it I don't have to worry about it.

Until next time this is Gary at MacMost Now.

Comments: 21 Responses to “MacMost Now 716: Encrypting USB Flash Drives”

    6/3/12 @ 9:03 pm

    Hi Gary, I don’t see the option for “Mac OS Extended (Journaled, Encrypted)… I’m running OS 10.7.4

      6/3/12 @ 9:15 pm

      Not sure why it wouldn’t show it to you. Perhaps try another drive?

    6/4/12 @ 4:42 am

    Thanks Gary, I found the problem. I had partitioned my thumb drive (Mac OS, & MS Dos) and was trying to format the existing Mac partition alone… not sure why this can’t be done… do you know of a way?

      6/4/12 @ 6:50 am

      Perhaps you can’t have an encrypted partition — only the whole drive.

    6/4/12 @ 1:52 pm

    Same Problem Here Garry&Richoff.I am running on a SnowLeopard 10.6.8.All i have is this:MS OS Extended(journaled); MS OS Extended ; MS OS Extended (Case sensitive,Journaled) MS OS Extended(Case sensitive) ; MS-DOS (FAT) and MS-DOS.
    Do i have to have this option on my Snow Leopard or how can activate it?
    Thank you

      6/4/12 @ 2:08 pm

      Pretty sure this isn’t available in Snow Leopard. You need to have Lion.

    John Wesley
    6/7/12 @ 11:23 am

    If I encrypt by 2 GB flash drive as Mac OS extended (encrypted), will this drive’s formatting still allow me to use it on me Windows 7 Bootcamp partition?

      6/7/12 @ 11:49 am

      I don’t think so. Not unless you also have some software installed in that Windows partition to read OS X-formatted drives. I don’t think Bootcamp has anything special to read OS X drives, but I’ve never looked into it.

    6/7/12 @ 11:40 am

    for those like me not using snow leopard, best to make an encrypted password protected dmg and save/move everything in there.

    J kehoe
    6/7/12 @ 3:47 pm

    Can this be done with a USB that already contains data, or will the data be erased?

      6/7/12 @ 3:59 pm

      Reformatting will erase the data. So you just copy it to your main hard drive. Reformat. Copy back.

    Frank Grimaldi
    6/30/12 @ 11:45 am

    Hi Gary, I don’t see the option for “Mac OS Extended (Journaled, Encrypted)… I’m running OS 10.7.4. I tried a second thumb drive, same problem????

      6/30/12 @ 12:08 pm

      Not sure why you don’t see it. Hard to tell where you nay be going on without a first-hand look.

        Frank Grimaldi
        7/3/12 @ 12:51 pm

        Hi Gary,
        I selected the wrong item, once I reviewed your video and selected the right item it worked. Thanks again.

    9/24/12 @ 6:25 pm

    What if i forgot the password for my encrypted usb drive. There is no info on the drive, i just want to be able to use it. I tried to use disk utility to re-format the drive but it won’t allow me to. Any help would be great. Thanks

      9/24/12 @ 7:18 pm

      I haven’t tried it, but you should be able to erase it. Try selecting the drive on the left and not the partition on the drive. See if that lets you erase it.

    Adriana Sanchez
    11/1/12 @ 11:09 pm

    I don’t feel very confident in using the Mac to encrypt my drive. For many years I was a windows fan until I switch to Mac. The Mac works great but the recent concerns on the internet about that Apple considers their system to be extremely secure but in fact it is working with out-to-date security measures made me purchase a third party software called “Encrypt Stick” from a company in Canada call ENC Securities. I’ve been using Encrypt Stick for a few month now and are very satisfied. Just a few days ago I realized that this product also works on my Windows machine which makes it even a lot better because a big draw back of everything that I do on my Mac (i.e. make documents with pages): it is’t compatible with any other OS.

    Charles De Poalo
    12/31/12 @ 3:27 pm

    Gary after setting a pass word can the Password be changed? How to?

    Thanks for your fine work.

      12/31/12 @ 3:39 pm

      Good question. Not sure. Try it — Control+Click on it after it is already encrypted. But my feeling is no, since it is encrypting the data using the password as a key. So you would need to un-encrypt it and then encrypt it again to get all the data encrypted with a new key.

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