NTFS and Mac security

[MacBH928]

Hello,
I installed Win7 on my macbook, while I was under the impression that NTFS can't read off Macs, I was amazed that win7 opened files from my mac partition and so did the Mac OS. It opened files from my Windows partition. how did this work? I don't know.

So what is worrying? While I do password to log in my Mac partition, logging into Win7 opens all my mac files with no password needed, and the opposite is true.

How can I protect my files from each partition accessing the other?

 

[0dev]

If you want to protect the partitions, encrypt them. FileVault does this natively in OS X (turn it on in System Preferences) and you can download TrueCrypt for your Windows partition. Do this and Windows can't read OS X's files and vice versa. It also means if someone steals your computer your data is safe

 

[MacBH928]

Very interesting, but this encryption, does it cause extra stress to the hard drive or the machine in general? does it cause any performance degrading?

is there any disadvantages or effects I should think about before I start using Encryption?

 

[murphychris]

Very interesting, but this encryption, does it cause extra stress to the hard drive or the machine in general? does it cause any performance degrading?

The disk will not care, it's just data either way. Depending on CPU, it might take up a bit of processing to do the encryption/decryption, but most people will not notice the effect because their CPU isn't fully utilized anyway. If you have a newer CPU with AES encryption instructions built in, then it's even less significant of an impact.

http://osxdaily.com/2011/08/10/filevault-2-benchmarks-disk-encryption-faster-mac-os-x-lion/

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Slightly different results:
http://www.practiceofcode.com/post/8681712620/macbook-air-ssd-benchmarks-2010-vs-2011-vs-lion

And in my own case, when it was encrypting the entire disk, the kernel process was about 15% higher on my 2008 laptop. (I don't have Lion on the Core i7 laptop to compare yet.) For ongoing usage, the kernel may have been 50% higher, somewhere around 8-12% total. But only during extensive file copying (reads or writes). It doesn't seem significant to me.

Also, the uncached tests are a little misleading for performance. Most people aren't writing out files so large that the cache will be filled. So the write performance is unlikely to be anywhere near as impacted as the uncached write tests suggest.

Another option is to create an encrypted disk image file, which mounts a disk like icon on your desktop into which you can save sensitive files. And just those files will be encrypted, stored inside the encrypted disk image.

 

[0dev]

I have a 2007 MacBook with FileVault on and I haven't noticed any degradation of performance. I can't speak for TrueCrypt but I imagine the same is true for that too.

The disk doesn't get damaged at all by encryption.

 

[throAU]

Encrypton performance will likely vary wildly depending on your CPU and the speed of the disk you're encrypting. If you have a core I series, they have AES encryption acceleration in hardware and are about 30x faster at doing AES (which filevault uses) than earlier CPUs.

You'd certainly notice the difference if running filevault on a core2 (or earlier) with SSD, i would wager (CPU probably can't keep up).

 

[MacBH928]

The disk will not care, it's just data either way. Depending on CPU, it might take up a bit of processing to do the encryption/decryption, but most people will not notice the effect because their CPU isn't fully utilized anyway. If you have a newer CPU with AES encryption instructions built in, then it's even less significant of an impact.

http://osxdaily.com/2011/08/10/filevault-2-benchmarks-disk-encryption-faster-mac-os-x-lion/

----------

Slightly different results:
http://www.practiceofcode.com/post/8681712620/macbook-air-ssd-benchmarks-2010-vs-2011-vs-lion

And in my own case, when it was encrypting the entire disk, the kernel process was about 15% higher on my 2008 laptop. (I don't have Lion on the Core i7 laptop to compare yet.) For ongoing usage, the kernel may have been 50% higher, somewhere around 8-12% total. But only during extensive file copying (reads or writes). It doesn't seem significant to me.

Also, the uncached tests are a little misleading for performance. Most people aren't writing out files so large that the cache will be filled. So the write performance is unlikely to be anywhere near as impacted as the uncached write tests suggest.

Another option is to create an encrypted disk image file, which mounts a disk like icon on your desktop into which you can save sensitive files. And just those files will be encrypted, stored inside the encrypted disk image.

I heard the disk image gets corrupt after some time, it does not last.


My computer is core2dou which means performance will get affected

 

[0dev]

I heard the disk image gets corrupt after some time, it does not last.

Not true.

My computer is core2dou which means performance will get affected

Mine's a Core 2 Duo from 2007 and the performance is fine.

 

[murphychris]

I heard the disk image gets corrupt after some time, it does not last.

I have placed my accounting files on a 128-bit encrypted disk image file, used at least weekly for 5 years, and never had a problem. About a year ago I created a new 256-bit encrypted disk image file, and transferred the data to it, and haven't had a problem with that one either. I'm fastidious about unmounting it though when not in use.

My computer is core2dou which means performance will get affected

It will consume some CPU, I have not found that it appreciably affects transfer rates in real world usage, or causes other apps to slow down, however.

If I were using something like Lightroom or Photoshop, that push the CPU to the limit at the same time it's read/writing to the disk, then yes I'd expect some noticeable performance reduction. The vast majority of the time, however, that CPU is at idle. So full disk (full partition actually) encryption is going to use a bit of that idle CPU that's you're usually not using anyway, and therefore you won't miss it.