Re: data security
You can try to buy warranty that contain retain defective media that mean that you get a new disk without returning the defective one. I know that the Israeli army does it (and I am sure that also Rafael does) Shahar - Original Message - From: Erez D To: linux-il Sent: Wednesday, February 04, 2009 12:07 PM Subject: data security hi one day this week, i started my computer, it behaved very strange - i had a blank screen for about 2 minutes before i got the boot screen, then it continued to boot from ... network the reason was that the hard drive has died. it wasn't even recognized by the bios. the computer was 2 months old, so i replaced the hard drive. when a hard drive dies and it is under warrenty, we need give the old one when we want it replaced. usuallyon the hard drive we have some personal things - pictures, documents, or confidential data if it belonged to a company etc... assuming the data is backed up (backing-up is an issue for another thread), we are left with the possibility of someone retriving data from the damaged drive. and when the drive is damaged, we can't even access it to erase that info before replacing it with a new one. so i though of a solution - use a crypto FS. but there are many problems with it. the practical problems are at least: 1. i do not know of a major linux distibution (i.e. redhat/ubuntu etc... ) that fully support crypto-fs out of the box, so if i use it, i will need to do manual changes every time i upgrade the system. 2. it is not really secured if the key is stored on disk. however if the key is not stored on disk, then the computer can not acces the data without human intervention, which is not good either when it comes to servers. and guys/girls, take my advice and back-up your data every short while. everybody thinks it will not happen to him. but it does. it is just a matter of time. erez. -- ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
data security
hi one day this week, i started my computer, it behaved very strange - i had a blank screen for about 2 minutes before i got the boot screen, then it continued to boot from ... network the reason was that the hard drive has died. it wasn't even recognized by the bios. the computer was 2 months old, so i replaced the hard drive. when a hard drive dies and it is under warrenty, we need give the old one when we want it replaced. usuallyon the hard drive we have some personal things - pictures, documents, or confidential data if it belonged to a company etc... assuming the data is backed up (backing-up is an issue for another thread), we are left with the possibility of someone retriving data from the damaged drive. and when the drive is damaged, we can't even access it to erase that info before replacing it with a new one. so i though of a solution - use a crypto FS. but there are many problems with it. the practical problems are at least: 1. i do not know of a major linux distibution (i.e. redhat/ubuntu etc... ) that fully support crypto-fs out of the box, so if i use it, i will need to do manual changes every time i upgrade the system. 2. it is not really secured if the key is stored on disk. however if the key is not stored on disk, then the computer can not acces the data without human intervention, which is not good either when it comes to servers. and guys/girls, take my advice and back-up your data every short while. everybody thinks it will not happen to him. but it does. it is just a matter of time. erez. ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
2009/2/4 Shachar Shemesh shac...@shemesh.biz Erez D wrote: so i though of a solution - use a crypto FS. but there are many problems with it. the practical problems are at least: 1. i do not know of a major linux distibution (i.e. redhat/ubuntu etc... ) that fully support crypto-fs out of the box, so if i use it, i will need to do manual changes every time i upgrade the system. Debian does. The installer even offers to install it for you. And so does Ubuntu. 2. it is not really secured if the key is stored on disk. however if the key is not stored on disk, then the computer can not acces the data without human intervention, which is not good either when it comes to servers. What I do is to not encrypt everything (which is a good idea anyways). The root file system and all of the service directories are not encrypted, and only the data is. I also tweak the Debian startup sequence to not ask me for the encryption password during boot. This way, the system boots without a password (but does not contain any data), and I use a small script to perform the actual crypted file system mount later (by which time I can log into the machine from ssh). I didn't bother to use it yet (not quite relevant for my desktops) but I think current Ubuntu (8.10) also offers to encrypt only your home directory - so part of your login procedure is to provide the key to mount just the home directory of the particular user. That way you get the PC up, you don't get a performance hit from encryption of data you actually don't need to hide, your data is safe until you login (and then I think it's still accessible only to you), multiple users can share the computer, each with their own key. All this is implied from installing Ubuntu from scratch on my work desktop last week (finally switched from Debian). No actual experience (yet). Cheers, --Amos ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
What about /etc/shadow and other sensitive files? so no encrypting your root filesystem is also an issue. What if you put the hard drive under a very strong magnetic field? - Original Message - Subject: Re: data security From: Shachar Shemesh shac...@shemesh.biz To: Orr Dunkelman orr.dunkel...@gmail.com CC: linux-il linux-il@cs.huji.ac.il,Erez D erez0...@gmail.com Date: 04-02-2009 13:02 Orr Dunkelman wrote: I guess that the configuration may still reveal some secrets (like which hosts are important enough to be in /etc/hosts), but it's better than nothing... On my laptop, most of the data is not encrypted. I discovered that compiling inside an encrypted partition is horrendously slow. Still, I do it if the data is sensitive (e.g. - all data and sources belonging to clients automatically goes there). I also keep certain important stuff there (my email client folder, my documents folder, browser history etc.) This is fairly easily achieved with symbolic links. Also, keep in mind that some things are automatically generated but still sensitive. The most important examples are my bash history file ( .bash_history under your home directory) and the database for the locate command (/var/cache/locate). The former shows a history of the commands I type, and the later has a list of all files on the system, including those inside the encrypted directory. This configuration is more dangerous, no doubt, as it is entirely possible that I have missed something (do share if you think of anything). It works pretty well for me, however. Shachar ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
On Wed, Feb 4, 2009 at 1:10 PM, Meir Michanie me...@riunx.com wrote: What about /etc/shadow and other sensitive files? so no encrypting your root filesystem is also an issue. What if you put the hard drive under a very strong magnetic field? and what if your laptop is stolen ... - Original Message - Subject: Re: data security From: Shachar Shemesh shac...@shemesh.biz To: Orr Dunkelman orr.dunkel...@gmail.com CC: linux-il linux-il@cs.huji.ac.il,Erez D erez0...@gmail.com Date: 04-02-2009 13:02 Orr Dunkelman wrote: I guess that the configuration may still reveal some secrets (like which hosts are important enough to be in /etc/hosts), but it's better than nothing... On my laptop, most of the data is not encrypted. I discovered that compiling inside an encrypted partition is horrendously slow. Still, I do it if the data is sensitive (e.g. - all data and sources belonging to clients automatically goes there). I also keep certain important stuff there (my email client folder, my documents folder, browser history etc.) This is fairly easily achieved with symbolic links. Also, keep in mind that some things are automatically generated but still sensitive. The most important examples are my bash history file ( .bash_history under your home directory) and the database for the locate command (/var/cache/locate). The former shows a history of the commands I type, and the later has a list of all files on the system, including those inside the encrypted directory. This configuration is more dangerous, no doubt, as it is entirely possible that I have missed something (do share if you think of anything). It works pretty well for me, however. Shachar ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
Orr Dunkelman wrote: The question is whether your swap partition is encrypted or not. In case it is not - you are probably writing too many secrets to the hard disk. If it is - well, then I can understand why the machine is slow. It is encrypted, but swap is hardly used on my machine. And I didn't say my machine was slow. I said that having my entire home dir encrypted made compilations slow. Besides that, knowing about speeds of encryption and hard drives, it seems that if you use good ciphers, there should be no real performance lose (I know that there is such, but I never figured out why). Maybe because both compilation and encryption are CPU bound? Shachar ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
Shachar Shemesh wrote: Orr Dunkelman wrote: The question is whether your swap partition is encrypted or not. In case it is not - you are probably writing too many secrets to the hard disk. If it is - well, then I can understand why the machine is slow. It is encrypted, but swap is hardly used on my machine. And I didn't say my machine was slow. I said that having my entire home dir encrypted made compilations slow. Besides that, knowing about speeds of encryption and hard drives, it seems that if you use good ciphers, there should be no real performance lose (I know that there is such, but I never figured out why). Maybe because both compilation and encryption are CPU bound? Shachar If you are really into that, work with VM and encrypt/decrypt the directory containing its files. ( Just an example, YMMV ) VM is pretty fast by now, even on desktop machines. Moish ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
He asked about what to do with his broken harddisk. - Original Message - Subject: Re: data security From: Erez D erez0...@gmail.com To: Meir Michanie me...@riunx.com CC: linux-il linux-il@cs.huji.ac.il Date: 04-02-2009 13:47 On Wed, Feb 4, 2009 at 1:10 PM, Meir Michanie me...@riunx.com wrote: What about /etc/shadow and other sensitive files? so no encrypting your root filesystem is also an issue. What if you put the hard drive under a very strong magnetic field? and what if your laptop is stolen ... - Original Message - Subject: Re: data security From: Shachar Shemesh shac...@shemesh.biz To: Orr Dunkelman orr.dunkel...@gmail.com CC: linux-il linux-il@cs.huji.ac.il,Erez D erez0...@gmail.com Date: 04-02-2009 13:02 Orr Dunkelman wrote: I guess that the configuration may still reveal some secrets (like which hosts are important enough to be in /etc/hosts), but it's better than nothing... On my laptop, most of the data is not encrypted. I discovered that compiling inside an encrypted partition is horrendously slow. Still, I do it if the data is sensitive (e.g. - all data and sources belonging to clients automatically goes there). I also keep certain important stuff there (my email client folder, my documents folder, browser history etc.) This is fairly easily achieved with symbolic links. Also, keep in mind that some things are automatically generated but still sensitive. The most important examples are my bash history file ( .bash_history under your home directory) and the database for the locate command (/var/cache/locate). The former shows a history of the commands I type, and the later has a list of all files on the system, including those inside the encrypted directory. This configuration is more dangerous, no doubt, as it is entirely possible that I have missed something (do share if you think of anything). It works pretty well for me, however. Shachar ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
Erez D wrote: so i though of a solution - use a crypto FS. but there are many problems with it. the practical problems are at least: 1. i do not know of a major linux distibution (i.e. redhat/ubuntu etc... ) that fully support crypto-fs out of the box, so if i use it, i will need to do manual changes every time i upgrade the system. Debian does. The installer even offers to install it for you. 2. it is not really secured if the key is stored on disk. however if the key is not stored on disk, then the computer can not acces the data without human intervention, which is not good either when it comes to servers. What I do is to not encrypt everything (which is a good idea anyways). The root file system and all of the service directories are not encrypted, and only the data is. I also tweak the Debian startup sequence to not ask me for the encryption password during boot. This way, the system boots without a password (but does not contain any data), and I use a small script to perform the actual crypted file system mount later (by which time I can log into the machine from ssh). Hope this helps. Shachar ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
Orr Dunkelman wrote: I guess that the configuration may still reveal some secrets (like which hosts are important enough to be in /etc/hosts), but it's better than nothing... On my laptop, most of the data is not encrypted. I discovered that compiling inside an encrypted partition is horrendously slow. Still, I do it if the data is sensitive (e.g. - all data and sources belonging to clients automatically goes there). I also keep certain important stuff there (my email client folder, my documents folder, browser history etc.) This is fairly easily achieved with symbolic links. Also, keep in mind that some things are automatically generated but still sensitive. The most important examples are my bash history file ( .bash_history under your home directory) and the database for the locate command (/var/cache/locate). The former shows a history of the commands I type, and the later has a list of all files on the system, including those inside the encrypted directory. This configuration is more dangerous, no doubt, as it is entirely possible that I have missed something (do share if you think of anything). It works pretty well for me, however. Shachar ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
Meir Michanie wrote: He asked about what to do with his broken harddisk. - Original Message - Subject: Re: data security From: Erez D erez0...@gmail.com To: Meir Michanie me...@riunx.com CC: linux-il linux-il@cs.huji.ac.il Date: 04-02-2009 13:47 On Wed, Feb 4, 2009 at 1:10 PM, Meir Michanie me...@riunx.com wrote: What about /etc/shadow and other sensitive files? so no encrypting your root filesystem is also an issue. What if you put the hard drive under a very strong magnetic field? and what if your laptop is stolen ... - Original Message - Subject: Re: data security From: Shachar Shemesh shac...@shemesh.biz To: Orr Dunkelman orr.dunkel...@gmail.com CC: linux-il linux-il@cs.huji.ac.il,Erez D erez0...@gmail.com Date: 04-02-2009 13:02 Orr Dunkelman wrote: I guess that the configuration may still reveal some secrets (like which hosts are important enough to be in /etc/hosts), but it's better than nothing... On my laptop, most of the data is not encrypted. I discovered that compiling inside an encrypted partition is horrendously slow. Still, I do it if the data is sensitive (e.g. - all data and sources belonging to clients automatically goes there). I also keep certain important stuff there (my email client folder, my documents folder, browser history etc.) This is fairly easily achieved with symbolic links. Also, keep in mind that some things are automatically generated but still sensitive. The most important examples are my bash history file ( .bash_history under your home directory) and the database for the locate command (/var/cache/locate). The former shows a history of the commands I type, and the later has a list of all files on the system, including those inside the encrypted directory. This configuration is more dangerous, no doubt, as it is entirely possible that I have missed something (do share if you think of anything). It works pretty well for me, however. Shachar Take an advice from them: http://www.willitblend.com/ or Locate road compactors http://www.iroads.co.il/MazInternet/General/Pages/HomePage.aspx or buy http://www.veritysystems.com/degaussers/hard-drive-degaussers.asp?sub_category=hdd Moish ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
On Wed, Feb 4, 2009 at 12:02 PM, Shachar Shemesh shac...@shemesh.biz wrote: Also, keep in mind that some things are automatically generated but still sensitive. The most important examples are my bash history file ( .bash_history under your home directory) and the database for the locate command (/var/cache/locate). The former shows a history of the commands I type, and the later has a list of all files on the system, including those inside the encrypted directory. Well, there is no problem in changing the location of locate's database, right? generate /var/sensitive/cache as a third partition, and throw there whatever you need. The question is whether your swap partition is encrypted or not. In case it is not - you are probably writing too many secrets to the hard disk. If it is - well, then I can understand why the machine is slow. Besides that, knowing about speeds of encryption and hard drives, it seems that if you use good ciphers, there should be no real performance lose (I know that there is such, but I never figured out why). -- Orr Dunkelman, orr.dunkel...@gmail.com a scientific man ought to have no wishes, no affections, -- a mere heart of stone - Charles Darwin. GPG fingerprint: C2D5 C6D6 9A24 9A95 C5B3 2023 6CAB 4A7C B73F D0AA (This key will never sign Emails, only other PGP keys. The key corresponds to o...@vipe.technion.ac.il) ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
This whole encryption thread reminded me of a recent xkcd: http://xkcd.com/538/ :-) --y On Wednesday 04 February 2009, Moish wrote: Shachar Shemesh wrote: Orr Dunkelman wrote: The question is whether your swap partition is encrypted or not. In case it is not - you are probably writing too many secrets to the hard disk. If it is - well, then I can understand why the machine is slow. It is encrypted, but swap is hardly used on my machine. And I didn't say my machine was slow. I said that having my entire home dir encrypted made compilations slow. Besides that, knowing about speeds of encryption and hard drives, it seems that if you use good ciphers, there should be no real performance lose (I know that there is such, but I never figured out why). Maybe because both compilation and encryption are CPU bound? Shachar If you are really into that, work with VM and encrypt/decrypt the directory containing its files. ( Just an example, YMMV ) VM is pretty fast by now, even on desktop machines. Moish ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il -- Yuval Hager [T] +972-77-341-4155 [...@] yu...@avramzon.net signature.asc Description: This is a digitally signed message part. ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
2009/2/4 Erez D erez0...@gmail.com: when a hard drive dies and it is under warrenty, we need give the old one when we want it replaced. usuallyon the hard drive we have some personal things - pictures, documents, or confidential data if it belonged to a company etc... assuming the data is backed up (backing-up is an issue for another thread), we are left with the possibility of someone retriving data from the damaged drive. and when the drive is damaged, we can't even access it to erase that info before replacing it with a new one. so i though of a solution - use a crypto FS. but there are many problems with it. the practical problems are at least: 1. i do not know of a major linux distibution (i.e. redhat/ubuntu etc... ) that fully support crypto-fs out of the box, so if i use it, i will need to do manual changes every time i upgrade the system. 2. it is not really secured if the key is stored on disk. however if the key is not stored on disk, then the computer can not acces the data without human intervention, which is not good either when it comes to servers. The solution is thus to have two partitions. One with the OS stuff and configuration, and one which is encrypted and contains your personal data. I guess that the configuration may still reveal some secrets (like which hosts are important enough to be in /etc/hosts), but it's better than nothing... -- Orr Dunkelman, orr.dunkel...@gmail.com a scientific man ought to have no wishes, no affections, -- a mere heart of stone - Charles Darwin. GPG fingerprint: C2D5 C6D6 9A24 9A95 C5B3 2023 6CAB 4A7C B73F D0AA (This key will never sign Emails, only other PGP keys. The key corresponds to o...@vipe.technion.ac.il) ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: data security
On Wednesday, 4 בFebruary 2009, Amos Shapira wrote: 2009/2/4 Shachar Shemesh shac...@shemesh.biz Erez D wrote: 1. i do not know of a major linux distibution (i.e. redhat/ubuntu etc... Debian does. The installer even offers to install it for you. And so does Ubuntu. And Fedora also of course ;-) -- Oron Peled Voice: +972-4-8228492 o...@actcom.co.il http://www.actcom.co.il/~oron No, You Can't Have My Rights, I'm Still Using Them ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
