*** This bug is a security vulnerability ***

Public security bug reported:

Hi,

as far as I understand, the "Encrypt the new Ubuntu installation for
security" option in the Ubuntu installer is meant to provide full disk
encryption.

However, when using that option, it seems like as if the encryption
would finish instantly, it literally does not seem to take any time at
all.

When using BitLocker on Windows to encrypt the entire disk, it can take
hours to fully encrypt the disk, even on SSDs. With BitLocker and other
encryption tools like DiskCryptor or TrueCrypt for example, there's also
a progress indicator, which shows how much of the disk is encrypted
already.

Why is that not the case with the "Encrypt the new Ubuntu installation
for security" option in the Ubuntu installer?

Even on my 1 TB SSD the encryption seems to be set up instantly and
there's no progress indicator whatsoever.

How's that possible?

Someone on the forum said:

> http://ubuntuforums.org/showthread.php?t=2330425&p=13516293#post13516293
>
> Data doesn't become encrypted until written

But if that would be true, then the "Encrypt the new Ubuntu installation
for security" option in the installer is not full disk encryption at
all.

If he is correct, then it does not encrypt the entire disk then. It only
encrypts used disk space. The empty space is not encrypted then.

At least with BitLocker you have the option to choose between encrypting
used disk space only or encrypting the entire disk, see following
screenshot for example:

https://i-technet.sec.s-msft.com/en-us/windows/jj983729.bitlocker-screen
(en-us,MSDN.10).jpg

On the forum it was also mentioned that:

> http://ubuntuforums.org/showthread.php?t=2330425&p=13516293#post13516293
>
> If you want to randomly initialize the storage areas PRIOR to writing 
> anything,
> that will take some. I seem to recall it being an optional checkbox for the 
> installation.

And, indeed, there is a "For more security: Overwrite empty disk space
(The installation might take much longer.)" option on the next screen
after the screen which has the "Encrypt the new Ubuntu installation for
security" option.

Now, the question is: If that option is checked, does it just overwrite
the empty disk space? Or does it also encrypt it?

I was assuming that it only overwrites it with zeros before encrypting
it. I was assuming that the entire disk would be encrypted anyway using
the Encrypt the new Ubuntu installation for security" option, regardless
of the "For more security: Overwrite empty disk space (The installation
might take much longer.)" option.

Regards

** Affects: ubiquity (Ubuntu)
     Importance: Undecided
         Status: New

** Information type changed from Public to Public Security

** Description changed:

  Hi,
  
  as far as I understand, the "Encrypt the new Ubuntu installation for
  security" option in the Ubuntu installer is meant to provide full disk
  encryption.
  
  However, when using that option, it seems like as if the encryption
  would finish instantly, it literally does not seem to take any time at
  all.
  
  When using BitLocker on Windows to encrypt the entire disk, it can take
  hours to fully encrypt the disk, even on SSDs. With BitLocker and other
  encryption tools like DiskCryptor or TrueCrypt for example, there's also
  a progress indicator, which shows how much of the disk is encrypted
  already.
  
  Why is that not the case with the "Encrypt the new Ubuntu installation
  for security" option in the Ubuntu installer?
  
  Even on my 1 TB SSD the encryption seems to be set up instantly and
  there's no progress indicator whatsoever.
  
  How's that possible?
  
  Someone on the forum said:
  
  > http://ubuntuforums.org/showthread.php?t=2330425&p=13516293#post13516293
- > 
+ >
  > Data doesn't become encrypted until written
  
  But if that would be true, then the "Encrypt the new Ubuntu installation
  for security" option in the installer is not full disk encryption at
  all.
  
  If he is correct, then it does not encrypt the entire disk then. It only
  encrypts used disk space. The empty space is not encrypted then.
  
  At least with BitLocker you have the option to choose between encrypting
  used disk space only or encrypting the entire disk, see following
  screenshot for example:
  
- https://i-technet.sec.s-msft.com/en-...s,MSDN.10).jpg
+ https://i-technet.sec.s-msft.com/en-us/windows/jj983729.bitlocker-screen
+ (en-us,MSDN.10).jpg
  
  On the forum it was also mentioned that:
  
  > http://ubuntuforums.org/showthread.php?t=2330425&p=13516293#post13516293
- > 
- > If you want to randomly initialize the storage areas PRIOR to writing 
anything, 
+ >
+ > If you want to randomly initialize the storage areas PRIOR to writing 
anything,
  > that will take some. I seem to recall it being an optional checkbox for the 
installation.
  
  And, indeed, there is a "For more security: Overwrite empty disk space
  (The installation might take much longer.)" option on the next screen
  after the screen which has the "Encrypt the new Ubuntu installation for
  security" option.
  
  Now, the question is: If that option is checked, does it just overwrite
  the empty disk space? Or does it also encrypt it?
  
  I was assuming that it only overwrites it with zeros before encrypting
  it. I was assuming that the entire disk would be encrypted anyway using
  the Encrypt the new Ubuntu installation for security" option, regardless
  of the "For more security: Overwrite empty disk space (The installation
  might take much longer.)" option.
  
  Regards

-- 
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https://bugs.launchpad.net/bugs/1602155

Title:
  "Encrypt the new Ubuntu installation for security" option does not
  seem to provide proper full disk encryption?

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