In this lesson, we're going to talk about
asset disposal and decommissioning.
Now an organization is going to expand
and modernize its technology stack over time
and there's going to be a significant volume of data,
software, hardware and services that are accumulated,
and eventually they're going to outlive
their usefulness and purpose.
However, we can't simply throw away these assets
in the trash.
Instead, we need to have a proper procedure in place
to ensure the data security, regulatory compliance,
and efficient use of resources is occurring.
To help us with this,
the National Institute of Standards and Technology
created a document known as the Special Publication 800-88
which is commonly referred to
as the Guidelines for Media Sanitization.
Now, these guidelines provide our organizations
with guidance on how to conduct sanitization,
destruction and certification for our asset disposal
and decommissioning processes.
Now, first we have sanitization.
Sanitization refers to the thorough process
of making data inaccessible and irretrievable
from a storage medium using traditional forensic techniques.
Now, whether the data is stored on a hard drive,
solid state device, memory card,
or other type of storage device,
sanitization is going to be used to ensure
that it completely is removed
so that it is impervious to recovery,
even with some advanced forensic techniques.
Common methods employed in sanitization
include overriding your data multiple times,
degaussing the storage medium,
or employing encryption techniques.
Our primary objective of sanitization
is to protect sensitive information
from unauthorized access,
especially when disposing of
or repurposing a storage device.
Now, one of our sanitization techniques that we commonly use
is to overwrite data multiple times.
Overwriting data multiple times involves replacing
the existing data on a storage device
with a random series of information
to ensure that the original data is going to be obscured
if anybody tries to recover it using forensic techniques.
Now, this overriding process is often repeated several times
to reduce any chance of the original data being recovered.
Most commonly, overwriting processes
are going to use a single pass, seven passes, or 35 passes,
depending on the classification level of the data
that you're trying to sanitize,
with higher classification levels needing more passes
during that overriding process.
Now, the logic behind this method is that each overwrite
is going to make it increasingly more difficult
for potential adversaries to retrieve any meaningful data
using forensic tools or techniques.
By employing this technique, we're not only ensuring
the confidentiality of our stored data,
we're also minimizing the risks
associated with data breaches or unauthorized access,
especially during device disposal or repurposing.
Now, another sanitization technique we have
is known as degaussing.
Now, degaussing involves using a single machine
called a degausser to produce a strong magnetic field
that can disrupt the magnetic domains on a storage device
like a hard disk drive or a tape backup.
This degaussing process renders the data on the device
unreadable and irretrievable.
Unlike overriding though which might leave
a small possibility of data recovery,
degaussing will completely erase
the magnetic properties of the storage medium
to ensure that the data is permanently destroyed.
However, it's also important to note
that once a device has been degaussed,
it could no longer be used for storage
because its fundamental ability to store data
has now been eliminated.
This method is especially valuable
when devices are set to be discarded or recycled
to ensure that no data remnants of sensitive information
remains on that discarded storage device.
Now, Secure Erase is our third method
and Secure Erase is another sanitization technique
that used to be very popular, and it was a precursor
to the newer cryptographic erase technique
that you're going to learn about.
Now with Secure Erase
we are aiming to completely delete data
from a storage device
while ensuring that it cannot be recovered
using traditional recovery tools or methods.
This method is typically going to be implemented
at the firmware level of a storage device
like a solid state device or a hard disk drive.
When the Secure Erase command is issued
the storage device's built-in erasure routine
is going to be activated
and it's going to purge all the data blocks
to make the data irretrievable from that device.
Overtime, some flaws were found
in the Secure Erase technique
and a newer, more secure technique
known as Cryptographic Erase or CE was introduced
to replace the Secure Erase technique
in most of our modern storage devices.
Now, Cryptographic Erase is going to leverage
encryption technologies as its primary mechanism
for doing data sanitization.
Now, when data is initially stored on a given device
it's going to be encrypted using cryptographic keys.
During the cryptographic erasure process,
instead of trying to erase the actual data on the device
we simply are going to deliberately destroy
or delete the encryption keys themself
because without these keys, the data remains on the device
but it's rendered unreadable.
So in practical terms, it's now considered irretrievable.
Now, one of the significant advantages
of using cryptographic erase
over traditional erasure methods is speed.
Because with cryptographic erase
we're only having to delete the encryption keys
and not all of the data on a one or two
or 10 terabyte hard disk drive.
This makes the entire sanitization process
really quick to perform
and it can be done in less than about 30 to 60 seconds
when you're doing a cryptographic erasure.
Also, because our data remains encrypted and indecipherable
without that description key
the storage device can then be repurposed
or resold without there being the risk of data leakage.
Next, let's talk about destruction.
Now, while sanitization is trying to make data unrecoverable
destruction goes a step further
by ensuring that the physical device itself
is beyond recovery or reuse.
The NIST guidelines recommend methods like shredding,
pulverizing, melting, or incinerating storage media
as possible forms of destruction.
For instance, I used to work
at the National Security Agency,
and whenever we decommissioned our old,
top secret workstations, we had to remove the hard drives
from those machines and then have them physically shredded
to prevent anyone from accessing
our nation's top secret information.
So if you're working in a high security environment
that include secret or top secret data,
usually data sanitization will not be considered
secure enough for this kind of high security environment.
Instead, we're going to use a data destruction technique
like shredding, pulverizing, melting, or incinerating
the storage device that is going to be used instead,
depending on the type of media and the nature of data
that it once held.
Now, once the data has been sanitized
or the storage device has been destroyed,
we want to document that the asset disposal
or destruction has been completed
by following a certification process.
According to the NIST standards
certification is an act of proof
that the data or hardware has been securely disposed of.
The certification can be especially important
for organizations who must comply
with strict regulatory controls or those organizations
that handle particularly sensitive data,
such as top secret government data, financial information,
or health records contained on your systems.
With certification, we are not merely focused
on the sanitization or destruction of the data
but we also want to ensure that we can provide evidence
that our organization is taking its data security
posture very seriously by creating an audit log
of the sanitization, disposal, or destruction process
for a given data set.
Now, when it comes to data, every piece of data
has what's known as a lifecycle and that lifecycle begins
when the data is first created and it ends
when the data is being disposed of or destroyed.
For this reason, it's important to consider
your data retention requirements
when you're developing your asset disposal
and destruction policies.
Now, data retention isn't about hoarding
every piece of data indefinitely, but instead,
we are focused on strategically deciding on what to keep
and for how long.
The data lifecycle is going to encompass stages
from data creation, data processing, data archiving,
and the eventual data destruction.
But why should we retain data in the first place?
Why not just delete everything
when you no longer need to use it?
Well, there's several reasons that might require us
to retain data.
Regulatory requirements, for example,
might mandate that certain types of data
like financial transactions or medical records
be preserved for a specific period of time.
Additionally, retained data could be valuable
if your organization needs to be able
to conduct historical analysis, trend prediction,
or even to resolve some disputes.
However, retaining everything is simply not feasible,
nor is it advisable.
Storing vast amounts of data comes with a cost
in terms of tangible things like server costs
and storage costs as well as intangible costs
like increasing the complexity of your data
and your system management.
Additionally, the more data that your organization retains,
the larger a target your data is going to become
for a cyber threat actor.
Personally, I like to think about this mantra
when I'm developing my data retention policies
within my organizations.
The more you store, the more you must secure.
So why don't we just retain everything?
Well, even though storage costs have been reduced
over the years it's still a pretty significant expense
when you try to keep everything,
especially for larger organizations
who store petabytes of data.
Moreover, storing data indefinitely
can lead to clutter that makes data retrieval
and analysis much more cumbersome and time consuming.
Another often overlooked aspect is data protection.
Every piece of data
no matter how trivial needs to be protected
from potential data breaches.
The more data you have
the more expansive your security measures
are going to need to be.
And this in turn translates into higher costs
and the need to make additional resource allocations.
So remember, asset disposal and decommissioning
is an important process that must be considered
so your assets can be properly handled
throughout their entire lifecycle
especially during retirement and disposal.
By following standardized procedures,
like the guidelines presented
by the National Institute of Standards and Technology,
we can ensure that we're not just in compliance
but we're also helping to increase our peace of mind.
Our end goal here is clear, dispose of assets securely,
retain data judiciously, and ensure the integrity
and reputation of our organizations remain untarnished.