What you’re going to realise pretty quickly
is that if you have a high need for security and/or privacy,
that this can be somewhat incompatible
with things being quick and easy,
if you try to do it all within the same environment or operating system.
So what I’m talking about here is Security Domains and Isolation,
and having different Security Domains and Isolation.
Sadly, it can be very difficult to get the operating system
that you use for daily use to be highly secure and to maintain privacy,
plus be fast enough for applications you might want to run
and for it to be easy to use.
So, if you want to use games
then if you’ve got full disk encryption,
it’s going to slow it down, as an example.
Which is why for everyday use,
you might have a low Security and/or Privacy Domain,
and when you want stronger security and/or privacy,
you use a different approach of Security Domain.
Security Domains are generally really either physical or virtual
in terms of how you can separate them in some way.
An example of a Physical Security Domain
could be that you have one lock down physical machine or laptop,
and the operating system and everything in it
is configured in a certain way that that gives you high security.
And you have another physical machine or laptop,
and that is for general use.
So that’s an example of a Physical Security Domain.
And you can also have Virtual Security Domains or Isolation.
A virtual example could be using Platform Virtualization software
or Hypervisors which, as we’ve discussed,
and you’ve seen, is software that emulates a whole physical computer,
and can often emulate multiple physical platforms.
Like having Windows as your Low Security Domain,
and perhaps a virtual machine that has Debian in it
for your High Security Domain.
There are actually quite a few options to give you
different Security Domains and Isolations
that aren’t too onerous,
including virtual machines is a good example.
So you can set yourself up these separate Security Domains or environments
if you really want to beef up security and privacy.
Virtual Isolation provides a barrier to compromise.
So if you have a virtual machine guest operating system,
so say for example Debian,
if this was compromised and your host operating system, say Windows,
then that would be difficult to access,
it would be difficult to get from Debian to Windows through the Hypervisor.
The Hypervisor would need to be exploitable,
or it would have to be poorly configured in some way
like you’ve allowed file sharing or something like that in order,
so the exploit from the Debian to the Windows environment can be done.
It’s worth noting that if security and/or privacy are paramount,
then you literally will need separate Security Domains for different tasks.
Not necessarily physical, but at least virtual.
The level of security you need to maintain high privacy
isn’t practical for day to day use of the internet.
Think about the type of Security Domains
that you might want as you go through the course.
Domains you might have in extreme cases could be Work Domain,
Personal, Banking,
a Temporary Domain: a Non-persistent Domain
that is used temporarily and then it’s destroyed, a High Privacy Domain.
All of these are possible in different ways with different techniques
and not necessarily that onerous, depending on how you set them up.
Let’s talk more about Physical Isolation.
Physical Separation provides the highest level of security and privacy.
It also protects you against any adversary
that has physical access to your device.
This would mean a different laptop or physical device
configured for security and/or privacy, and another for general use.
Let’s talk about some of the situations where Physical might make sense,
or a Physical Security Domain.
If you need, for example to enter a country
where Customs can access your laptop,
which to be clear is most countries,
many which have laws to force you to give up your password,
or can take your laptop,
or other countries where it’s even worse,
where they can use forms of threats and intimidation,
and abuse, and violence
in order for you to disclose your password
or get access to your laptop.
With Physical Separation,
you simply don’t take the laptop with the sensitive information
or the things you’re trying to keep private away from them.
This is something that I’ve actually had to recommend for Corporate clients
who need to travel to particular area’s or parts of the world
where they have valuable information
that we knew the Governments would potentially want to get hold of.
Those clients don’t want to be in a situation
where they have to resist forms of intimidation.
So do consider the laws of other countries if you travel.
Even adult material could be a crime in other legal jurisdictions.
If you have a Threat Agent that could visit your location,
you can physically hide or lock away a secure laptop,
making it impossible for it to be forensically examined
if they can’t actually find it.
And you keep a more standard laptop available.
With Physical Separation,
if your standard laptop is compromised by your Threat Agent,
that could be via Malware or via some other means,
because you have kept Physical Separation,
they can’t get access to your secure data from your standard laptop.
You don’t even have to use your own equipment
when it comes to Physical Isolation or a Physical Security Domain.
This can be dangerous, of course,
to use other people’s equipment for both privacy and security
if you don't take the right precautions,
which we'll cover as part of the course.
But you could use, for example,
an internet café to send an anonymous message.
You could also maybe boot that machine
with your own operating system and configurations.
You could use a internet connection that you don’t own, for privacy,
these are all separations of Physical Security Domains.
You could have a separate router,
or separate network equipment for a particular type of privacy activity.
You could have separate network cards,
or WiFi cards or Ethernet adaptors.
Physical devices can be tied back to the purchaser in some instances.
For example, the network cards within physical devices
have unique MAC addresses or hardware addresses.
If you purchase your secure laptop anonymously,
then the MAC, if somebody is able to determine it,
cannot be traced back to you.
There are ways to change your MAC address
which we can cover if you’re using a Virtual form of Security Domain.
But having an anonymously purchased laptop
provides an extra lair within the Physical Domain of Security.
Some Virtual Isolation is slow,
for example using virtual machines or hidden operating systems
and having a separate machine for speed and usability might be needed.
There are quite a few disadvantages though to having Physical Separation.
It means that you have to have another machine, which,
or multiple machines if you want different Security Domains,
which is cumbersome, and it’s expensive
and it can just generally be annoying and just inconvenient for your situation.
Transferring data between physical machines
really breaks Physical Isolation and it breaks those separate Security Domains,
so it’s hard to transfer data securely.
Physically separate machines are also just as vulnerable to attack,
even though they’re in separate domains.
So just having a separate machine is no good, it has to be secure as well.
The more domains you have or the more machines you have,
you end up having to keep them all up to date
and you have to keep them all secure.
And also, Malware has been known to bridge physical devices
called the Air Gap and that has been demonstrated,
which we'll discuss more about.
So there are some cases for Physical Separation
and Physical Security Domains,
and this is something that will be unique to your situation
as to whether or not you think you need a Physical Security Domain.
Let’s talk about some of the virtual ways you can create
separate Security Domains and Isolation.
First point worth making is that Virtual Separation,
a technology used to create the virtualisation can be attacked
in attempt to bypass the one Security Domain
and get into the other.
To create separate domains you could do things like dual booting,
you can use Platform virtualisation software and hypervisors,
the likes of VMware, Virtualbox,
Vagrant, Hyper-V, VPC.
There’s also Kernel Virtual Machine,
there’s Jails or BSD Jails,
Zones, Linux Containers, Docker.
You can also have hidden operating systems,
VeraCrypt and TrueCrypt provide that functionality.
You can have separate hard drive partitions
that are encrypted and hidden.
You can have things like Sandboxes.
You can have portable apps.
You can have non-persistent operating systems like Tails,
Knoppix, Puppy Linux,
JonDo Live, Tiny Core Linux.
You can have bootable USBs.
You can have operating systems
that are dedicated to Isolation/Separation like Qubes,
which is a very good operating system.
So there are lots of ways to create Security Domains
through Isolation and Separation.
And the useful ones we'll be covering throughout the course.