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An EFS encryption question.


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Guest Brian Komar
Posted

Not a good idea.

The first time that you forget to import the PKCS#12 before you attempt to

access a file, a new EFS certificate will be generated

From that point on, all newly encrypted files will use the new default EFS

key

If you want to have the removal of the EFS certificate from software, then I

recommend you move to Vista and use a smart-card based EFS certificate

Brian

 

"bagassa" <not@available.com> wrote in message

news:e8Eqa9INJHA.5692@TK2MSFTNGP02.phx.gbl...<span style="color:blue">

> Good afternoon everyone,

>

> What I like to do is lock some of my sensitive files using the windows EFS

> encryption so that if someone were to steal my computer and somehow hack

> the password into my account, they still would not be able to read the

> files.

>

> If I were to:

>

> 1. encrypt the files

> 2. then export the "encrypting file system" certificate from the

> certificate manager (in the personal folder) to a thumb drive (and a

> backup drive).

> 3. delete the certificate managers copy

> 4. Every time I want to access the files, I plug the thumb drive in, and

> use it to decrypt the files.

>

> Is this a good way to do it ? Any red flags here ?

>

> Thanks for your time and help

>

> Peter

> </span>

Guest bagassa
Posted

Good afternoon everyone,

 

What I like to do is lock some of my sensitive files using the windows EFS

encryption so that if someone were to steal my computer and somehow hack the

password into my account, they still would not be able to read the files.

 

If I were to:

 

1. encrypt the files

2. then export the "encrypting file system" certificate from the certificate

manager (in the personal folder) to a thumb drive (and a backup drive).

3. delete the certificate managers copy

4. Every time I want to access the files, I plug the thumb drive in, and use

it to decrypt the files.

 

Is this a good way to do it ? Any red flags here ?

 

Thanks for your time and help

 

Peter

Guest Brian Komar
Posted

Inline...

"bagassa" <not@available.com> wrote in message

news:eFmgzvUNJHA.2824@TK2MSFTNGP06.phx.gbl...<span style="color:blue">

> Good afternoon Brian,

>

> You raised a good point. Does this mean that the burglar who stole my

> computer and broke into my account could still read the files, simply

> because Windows will always make a new certificate ?</span>

No. They would need access to the removed certificate's private key to open

previous files

<span style="color:blue">

>

> There is no registry change that can stop this automatic generation?</span>

No. You need to read the whitepaper on how EFS works.

You could prevent the creation of self-signed EFS, but the client would

still either request a Basic EFS certificate or autoenroll another

certificate.

 

<span style="color:blue">

>

> About those smart card readers you mentioned. Where can I get a simple

> one at a reasonable price ?</span>

You need three things:

1) Smart card

2) Smart card reader

3) Middleware/mini-driver

Google is your friend. Search for Gemalto

 

 

<span style="color:blue">

>

> Thanks for your time and input, Brian.

>

> Peter

>

> ========================================

><span style="color:green">

>> Not a good idea.

>> The first time that you forget to import the PKCS#12 before you attempt

>> to access a file, a new EFS certificate will be generated

>> From that point on, all newly encrypted files will use the new default

>> EFS key

>> If you want to have the removal of the EFS certificate from software,

>> then I recommend you move to Vista and use a smart-card based EFS

>> certificate

>>

>> Brian

>></span>

> ========================================<span style="color:green"><span style="color:darkred">

>>>

>>> What I like to do is lock some of my sensitive files using the windows

>>> EFS encryption so that if someone were to steal my computer and somehow

>>> hack the password into my account, they still would not be able to read

>>> the files.

>>>

>>> If I were to:

>>>

>>> 1. encrypt the files

>>> 2. then export the "encrypting file system" certificate from the

>>> certificate manager (in the personal folder) to a thumb drive (and a

>>> backup drive).

>>> 3. delete the certificate managers copy

>>> 4. Every time I want to access the files, I plug the thumb drive in, and

>>> use it to decrypt the files.

>>>

>>> Is this a good way to do it ? Any red flags here ?

>>>

>>> Thanks for your time and help

>>>

>>> Peter</span></span>

> </span>

Guest bagassa
Posted

Good afternoon Brian,

 

You raised a good point. Does this mean that the burglar who stole my

computer and broke into my account could still read the files, simply

because Windows will always make a new certificate ?

 

There is no registry change that can stop this automatic generation?

 

About those smart card readers you mentioned. Where can I get a simple one

at a reasonable price ?

 

Thanks for your time and input, Brian.

 

Peter

 

========================================

<span style="color:blue">

> Not a good idea.

> The first time that you forget to import the PKCS#12 before you attempt to

> access a file, a new EFS certificate will be generated

> From that point on, all newly encrypted files will use the new default EFS

> key

> If you want to have the removal of the EFS certificate from software, then

> I recommend you move to Vista and use a smart-card based EFS certificate

>

> Brian

></span>

========================================<span style="color:blue"><span style="color:green">

>>

>> What I like to do is lock some of my sensitive files using the windows

>> EFS encryption so that if someone were to steal my computer and somehow

>> hack the password into my account, they still would not be able to read

>> the files.

>>

>> If I were to:

>>

>> 1. encrypt the files

>> 2. then export the "encrypting file system" certificate from the

>> certificate manager (in the personal folder) to a thumb drive (and a

>> backup drive).

>> 3. delete the certificate managers copy

>> 4. Every time I want to access the files, I plug the thumb drive in, and

>> use it to decrypt the files.

>>

>> Is this a good way to do it ? Any red flags here ?

>>

>> Thanks for your time and help

>>

>> Peter </span></span>

Guest bagassa
Posted

Last question Brian,

 

The only white paper I found on the MS website talks about security in

general, or about the BitLocker feature which I don't have (I have Vista

Business).

 

Can I get a link to that EFS white paper that you mentioned ?

 

Regards,

 

Peter

 

==========================

"Brian Komar" <brian.komar@nospam.identit.ca> wrote in message

news:%23Eyk8%23UNJHA.5232@TK2MSFTNGP05.phx.gbl...<span style="color:blue">

> Inline...

><span style="color:green">

>> Good afternoon Brian,

>>

>> You raised a good point. Does this mean that the burglar who stole my

>> computer and broke into my account could still read the files, simply

>> because Windows will always make a new certificate ?</span>

> No. They would need access to the removed certificate's private key to

> open previous files

><span style="color:green">

>>

>> There is no registry change that can stop this automatic generation?</span>

> No. You need to read the whitepaper on how EFS works.

> You could prevent the creation of self-signed EFS, but the client would

> still either request a Basic EFS certificate or autoenroll another

> certificate.

>

><span style="color:green">

>>

>> About those smart card readers you mentioned. Where can I get a simple

>> one at a reasonable price ?</span>

> You need three things:

> 1) Smart card

> 2) Smart card reader

> 3) Middleware/mini-driver

> Google is your friend. Search for Gemalto

>

> Thanks for your time and input, Brian.

>

> Peter

></span>

Guest GreenieLeBrun
Posted

bagassa wrote:<span style="color:blue">

> Last question Brian,

>

> The only white paper I found on the MS website talks about security in

> general, or about the BitLocker feature which I don't have (I have

> Vista Business).

>

> Can I get a link to that EFS white paper that you mentioned ?

>

> Regards,

>

> Peter

>

> ==========================

> "Brian Komar" <brian.komar@nospam.identit.ca> wrote in message

> news:%23Eyk8%23UNJHA.5232@TK2MSFTNGP05.phx.gbl...<span style="color:green">

>> Inline...

>><span style="color:darkred">

>>> Good afternoon Brian,

>>>

>>> You raised a good point. Does this mean that the burglar who stole

>>> my computer and broke into my account could still read the files,

>>> simply because Windows will always make a new certificate ?</span>

>> No. They would need access to the removed certificate's private key

>> to open previous files

>><span style="color:darkred">

>>>

>>> There is no registry change that can stop this automatic generation?</span>

>> No. You need to read the whitepaper on how EFS works.

>> You could prevent the creation of self-signed EFS, but the client

>> would still either request a Basic EFS certificate or autoenroll

>> another certificate.

>>

>><span style="color:darkred">

>>>

>>> About those smart card readers you mentioned. Where can I get a

>>> simple one at a reasonable price ?</span>

>> You need three things:

>> 1) Smart card

>> 2) Smart card reader

>> 3) Middleware/mini-driver

>> Google is your friend. Search for Gemalto

>>

>> Thanks for your time and input, Brian.

>>

>> Peter</span></span>

 

These may help:-

 

The Encrypting File System

http://www.microsoft.com/technet/security/...phyetc/efs.mspx

 

Best practices for the Encrypting File System

http://support.microsoft.com/kb/223316/en-us

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