MacMost Now 41: Secure Empty Trash Login Alias

Gary Rosenzweig answers some questions from viewers, including ones about using secure empty trash, requiring people to logon to use some applications and the difference between aliases and symbolic links.

Video Transcript
"Hi this is Gary Rosenzweig with MacMost Now. Let's get to some viewer email.
Ed writes 'Having recently upgraded to Leopard I was wondering why the Secure Empty Trash feature sometimes takes forever even though there are only a few small files in the trash.' Actually the Secure Empty Trash feature makes for an interesting topic in and of itself. I bet you most people don't even know about this. Let me show you. Okay. So to use the Secure Empty Trash feature you need to go to the finder menu and you'll see the regular empty trash menu item but also there's a Secure Empty Trash item as well. So you can select that and you get a normal warning. It's hard to tell exactly why you're getting this problem. A few people have reported it. Now one explanation can be that the files are very large. For instance, you could have two files in there and one could be one gig and the other could be 1K, whereas another time you could have two 1K files. What's going to happen when you erase with Secure Empty Trash is you're going to get a rewrite every single bite on the files that used to be used by those files. So a large file will take longer than a small file. Now normally when you empty the trash it just erases the link to those files so you could have ten large file and they take the same amount of time to delete as ten small files. But not so with Secure Empty trash. So it could be the file sizes, not the number of files you need to look for. But it does seem like there are enough reports that maybe there is something wrong with Secure Empty Trash that sometimes it does take a little bit longer. It's really hard to tell. We don't have any problems here.
However there is alternative. There is another way to simulate Secure Empty Trash. So another way to go ahead and securely empty your trash is actually just throw away the trash normally. But then once you do that what you would want to do is go to your application utilities folder and open up disc utility. So what disc utility has is an extra function. You select your drive, Macintosh hard drive in this case, and you click on erase. Now you're not going to erase the entire drive, what you're going to do is look at this button here which is erase free space, click on that and it gives you several different options so you can zero out the files. You can zero out the files seven times or you can actually do 35. Now of course these take an extremely long period of time to do. I guess the extra safety here is that if somebody's trying to read your drive with some sort of incredible type of technology they won't find any trace of these files because they've been erased over so many a times there's not even residual memory on the drives.
Ed also had another question I though was interesting. He wanted to know if it's possible to force someone to enter a password every time every time the mail application's launched, force someone to enter a password every time the transmit application is launched or have a particular folder protected the first time any user tries to access it. Actually, I don't know any way to do any of these particular things but I think you're going about it the wrong way. I think instead what we should do is create a special user account that you have to log into in order to get access to all these things. So for instance, all your mail and transmit preferences would be saved under that one account and also that one folder will be there. That way the only way to access it is if you know the password for that account. Then make sure you log out of that account or even set it to automatically log out when you haven't used it for a while or when the computer goes to sleep or anything like that. That makes sure that all those things are secure and only for that person that knows the password to that account. That's my suggestion anyway and how I would go about it.
Justin wrote, 'Can you tell how you export your videos to look so good on blip.tv? A run down of the settings would be great.' Actually getting the correct settings can be a real pain. If you just set one thing a little wrong it won't or iPod or iPhones and won't download correctly in iTunes. So what we do is simply use the share menu in iMovie and the export function there. They've got some preset things there; we use the medium setting which creates a 640 by 360 wide screen video and this works everywhere. It actually creates an M4V file. We change its file name to MP4 and that allows us to upload it to just about any service, including You Tube and Revver and all sorts of other video services. We're on about a dozen on the Internet.
Lucas wrote, 'I've heard something about links called symbolic links. Is there any difference between and normal with control click?' So basically a symbolic link is something that you can create using a terminal window and a special LN command. These are typical on Linux and Unix machines. Aliases seem to do the same thing but aliases are a little smarter. You can actually move the file that an alias is linked to and the alias will follow that file. Whereas if you move the file that a symbolic link is linked to you will lose that symbolic link. So you probably want to stick to aliases for most things that you do. You can use symbolic links if you're a Linux guru.
That's all the questions for now. If you've got questions for me you can email me at questions (-at-) macmost.com. If you enjoy these podcasts please subscribe to them at iTunes and tell your friends to do the same. You can also review us there. We hope to one day to make it to the front page of the iTunes Podcast directory. Until next time this is Gary Rosenzweig with MacMost Now.

Comments: 2 Responses to “MacMost Now 41: Secure Empty Trash Login Alias”

    richard BENDER
    3/12/10 @ 1:10 pm

    In December 09 just before my Mac crashed and burned and had to have a new hard drive installed I hired a MAC guru to come to my office and help me with many things. He also helped me change the over write settings to MORE securely empty trash. I cannot locate my notes that told me how to do it again. Can/will you assist me in this quest? Walk me thru the steps?

    Thank you in advance,
    Rich

      3/13/10 @ 8:34 am

      I can’t imagine what steps he would have taken. Securely Empty Trash overwrites those bits on your hard drive with zeros. I can’t see how changing some settings would do more than that. Perhaps this was a long time ago, before the current function was available?

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