Peter@TheNetherlands

Q: secure file deletion not in El Capitan

Everybody noticed? Secure deletion of your files in your recycle-bin is not there any more in El Capitan.

 

Who has the solution for this problem?

iMac, OS X El Capitan (10.11)

Posted on Oct 1, 2015 7:22 AM

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Q: secure file deletion not in El Capitan

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  • by Ric Donato,Helpful

    Ric Donato Ric Donato Oct 1, 2015 8:20 AM in response to Peter@TheNetherlands
    Level 4 (1,109 points)
    Oct 1, 2015 8:20 AM in response to Peter@TheNetherlands

    Using Terminal here is my solution:

    1. Create a new empty desktop folder, it will be labeled  untitled folder.
    2. Move the files from Trash to that folder.
    3. Open Terminal, wait until you see your name followed by the $ symbol, then type: srm -rfv -s  
    4. NOTE: there is a space after srm and -rfv  and -s
    5. Drag that folder you placed those files into, again mine is "untitled folder" onto terminal
    6. Press return.

     

    Here is more information on that line: srm -rfv -s  https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/ man1/srm.1.html



    Hope that helps you.

     

    Cordially,

  • by babowa,

    babowa babowa Oct 1, 2015 8:06 AM in response to Peter@TheNetherlands
    Level 7 (31,900 points)
    iPad
    Oct 1, 2015 8:06 AM in response to Peter@TheNetherlands

    Who has the solution for this problem?

     

    There is no problem - using secure erase was never necessary as the space would be overwritten by other things shortly after you erased the files. So, Apple fixed it by removing the option. As well, secure erase cannot be used on SSDs and many machines have SSDs these days, so it was becoming superfluous. Rather than using a terminal hack, just use the regular erase function; the only time you need to be concerned about a secure erase is when you are about to sell your Mac.

  • by Ric Donato,

    Ric Donato Ric Donato Oct 1, 2015 9:24 AM in response to babowa
    Level 4 (1,109 points)
    Oct 1, 2015 9:24 AM in response to babowa

    Hello babowa,

    srm -fv -s is not a "hack", it is a legitimate terminal technique for deleting files that Trash may be unable to erase.


    Thank you for that SSD information, I was not aware that secure delete does not work on SSD. My MBP is 2010 model with a HDD, thus, you taught me something new. On the SSD or HDD with much free space it may take a while rewriting to those locations. To me it would make those files recoverable, if that is true then deleting them would not be too secure. That is the reason folks used secure delete.

     

    Question: if Secure delete does not work on SSD, does the same apply to Disk Utility Erase Free Space as well? Being as I do not have a SSD truly I am all ears for that information. Looking forward to your response, it will help us.

     

     

     

    Cordially,

  • by babowa,

    babowa babowa Oct 1, 2015 9:33 AM in response to Ric Donato
    Level 7 (31,900 points)
    iPad
    Oct 1, 2015 9:33 AM in response to Ric Donato

    Well, sorry for the terminology - but to me, any elemental changes done to the system within the terminal from the default is a hack. You are changing the way the system is designed to work.

     

    That being so to me it would make those files recoverable, if that is true then just deleting them would not be too secure. That is the reason folks used secure delete.

     

    Well, I still see no reason for it: unless you are sharing your computer and/or giving admin rights to someone else, why do you need a secure delete - unless you are giving the machine to someone else (selling it). I've never used it; neither have I ever used clear empty space. The only time I did was when I erased the entire drive with a 3-pass erase (7-pass is an overkill) before selling it. Hence I can't answer your question re. clear empty space (and both articles below were published before el Capitan).

     

    And, as for SSDs - here are two articles:

     

    https://discussions.apple.com/docs/DOC-5521

     

    http://www.macworld.com/article/2906499/mac-911-how-to-erase-your-macs-hard-driv e-the-right-way.html

  • by Ric Donato,

    Ric Donato Ric Donato Oct 1, 2015 1:10 PM in response to babowa
    Level 4 (1,109 points)
    Oct 1, 2015 1:10 PM in response to babowa

    Hi babowa,

    No, an apology is not needed; you say tomāto, I say tomãto.

    Thank you for the links, interesting reading. Now I know and understand new things about SSD. Also, I appreciate your time explaining it.

     

    Cordially,

  • by JWD88,

    JWD88 JWD88 Nov 16, 2015 4:37 PM in response to babowa
    Level 1 (28 points)
    Nov 16, 2015 4:37 PM in response to babowa

    "There is no problem - using secure erase was never necessary as the space would be overwritten by other things shortly after you erased the files. So, Apple fixed it by removing the option."


    I respectfully disagree--strongly. Removing the SD option is another in a long line of dumbing-down moves that Apple has taken, esp since Jobs died. It is true that SSDs are difficult to securely erase, but most people still have regular hard drives. Also, you can't say things will be overwritten "shortly". They may or may not, and undelete software is simple and free for anyone who gets ahold of your computer (burglar). There are many reasons to want to securely delete a file, and this just makes a simple job more difficult. There was no reason to remove this function, and Apple should be ashamed of itself.

  • by babowa,

    babowa babowa Nov 16, 2015 6:48 PM in response to JWD88
    Level 7 (31,900 points)
    iPad
    Nov 16, 2015 6:48 PM in response to JWD88

    Well, my opinion actually matters little as the point is: the option has been removed and no amount of ranting will change that. It might have seemed necessary or important to you; unfortunately, it did not work reliably, so it was removed. Here is the info from Apple:

     

    https://support.apple.com/en-us/HT205267

     

    Finder

    Available for: Mac OS X v10.6.8 and later

    Impact: The "Secure Empty Trash" feature may not securely delete files placed in the Trash

    Description: An issue existed in guaranteeing secure deletion of Trash files on some systems, such as those with flash storage. This issue was addressed by removing the "Secure Empty Trash" option.


    https://support.apple.com/kb/PH5849?viewlocale=en_US&locale=en_US

     

    You can’t securely erase a CD, DVD, or a solid-state drive. If you don’t want data recovered from a solid-state drive, use full disk encryption.