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- In this lesson, 15.2,

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we're gonna focus in on
the information lifecycle,

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and then specifically deletion,

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disposal and destruction.

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Let's start with walking through

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the information lifecycle.

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We start with either creating information

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or collecting information.

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And if we're collecting information,

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we really wanna be cognizant

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of those OECD privacy principles,

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that we only collect what we need.

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That we collect it with
notice and lawfully.

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That we already specified the use

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for whatever we're gonna collect.

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We're not just gonna collect data

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'cause we think it might
be useful later on, right?

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We're gonna be very deliberate

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of what we're collecting.

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Or we may be creating,

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maybe we're creating a spreadsheet

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or we're creating a database,

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or we're writing the great American novel,

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but we could be creating or collecting.

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That's the beginning part
of information lifecycle.

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Then in our production environment,

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we're going to be using that information,

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but there is a parallel track.

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For some of that data,

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we are going to make copies of it

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and we're going to be retaining it.

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So we have these two parallel tracks

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of use and retention.

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And then we get to the
end of its useful life,

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whether it's been in use in production

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or it's been information
that we have archived.

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And we get to the end of it

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and we either have to dispose of it,

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or we need to go a step further

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and actually destruct the media

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that that information or
that data is written on.

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So you know how to use data,

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so let's talk about retention of data.

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Retention is a set of
rules, really a policy

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that dictates the data sets

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that must be kept and for how long.

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The data retention
strategies must be aligned

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with business and legal requirements.

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So, for example, here in the US, the SEC,

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the Securities and Exchange Commission,

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requires that certain financial documents

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be retained for seven years.

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And the IRS, our Internal Revenue Service,

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says that payroll tax records

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have to be retained for seven years.

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And there may be other state

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and federal requirements
that apply to you.

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And, of course, wherever
you are in the world,

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right, you wanna look at the requirements

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for your jurisdiction.

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Then there may be other data that you want

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to retain, kind of on a discretionary.

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It's like, oh, I think
we should keep our email

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or I wanna keep X, Y, Z kind of records.

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And my suggestion to you is before

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you make that decision,

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that you consult with legal counsel

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because there's always pros

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and cons of retaining information.

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So once we have determined
our retention rules,

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then we go through the process

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of actually saving that data.

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And the process is
referred to as archiving.

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Archiving, the process

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of securely storing
original, unmodified files

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for later potential retrieval.

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Now, data should be archived

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in accordance with its retention schedule,

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it should be stored securely in accordance

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with its classification

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and it should be properly disposed of

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at the end of the retention period.

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Now, I wanna make sure that we make

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the distinction between
archiving and backup.

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When we archive something,

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we are making a copy of it,

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and that copy will
forevermore remain unmodified.

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So we have an original document.

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We make another copy of it.

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It looks exactly like the
original document, right?

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It is pristine, it is unmodified

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and it is put away so
if we need to go back

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to that original document
later on, we can.

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That's really different
than backup and replication.

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Backup and replication is the process

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of making copies of data

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to ensure recoverability.

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So what we're trying to do there

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is our production data, right, if,

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for some reason, it got corrupted,

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it got deleted, system failed, whatever,

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we could restore that production data.

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So backup and replication

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is a distinctly different process

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than archiving 'cause in
backup and replication,

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we're always backing up whatever

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the current data state is,

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whatever that data looks
like at that moment.

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Where, once again, archiving,

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we store this unmodified, pristine file

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that maybe we have to go back to later on,

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no matter how many times it's been edited

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further down the line.

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Now, there might be another situation

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that you encounter where you have

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to also save documents,
and that's a legal hold.

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A legal hold is a requirement

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for an organization to preserve all forms

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of relevant information
when litigation, audit

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or a government investigation

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is reasonably anticipated.

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Now, the objective is to
avoid evidence spoliation,

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which means that you
either modify that evidence

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or even delete that evidence.

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Now, a legal hold is gonna supersede

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your organizational retention policies.

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So perhaps you don't
have a retention policy

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on saving your emails,

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but you get a legal hold,

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and the legal hold says all emails

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from person A to person B, you must save.

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So even though that's not
in your retention policy,

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this legal hold is going to supersede

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that retention policy.

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And then we get to the end of useful life.

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So we've reached the end of useful life

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for the data in production,

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or it could be end of
useful life for the data

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that you now have archived,

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and we need to get rid of it.

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So how do we do it?

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Well, we know that
conventional data deletion

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does not delete data, right?

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If you just click delete,

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it doesn't delete the data, right?

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If you put it in the trash bin

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and then you empty the trash bin,

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it does not delete the data.

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So what does happen?

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Well, when a file is deleted,

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the corresponding entry

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in the file system directory is cleared

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and the directory index is marked

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as ready to be reused,

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but that ones and zeros still exist

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on the media, right?

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The original file remains intact

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until the space is used

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and the original file is overwritten.

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Now, often, when we overwrite,

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we're not overwriting the full file.

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So it's very possible

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that potentially all or part

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of a deleted file entry can be recovered.

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Data remanence refers
to the residual traces

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of data that remain on that storage medium

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even after attempts
have been made to erase

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or delete the information.

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Now, there are a number of techniques

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that you wanna know to
counter data remanence,

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and these include data wiping, also known

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as data sanitization, encryption

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and physical destruction.

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And then TRIM is a
command that can be used

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by operating systems to inform

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a solid state drive,

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which many of our systems have these days,

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which blocks of data are no longer in use.

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So when TRIM is executed,

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the solid state drive

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may immediately erase the associated data,

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reducing the likelihood of remanence.

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So data sanitization, which is also known

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as disk wiping, is a clearing technique

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that overwrites all addressable storage

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and indexing locations multiple times.

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A standard that you may
be familiar with is one

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that was created by the United States

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Department of Defense,

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and it's DoD 5220.22-M,

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which is a standard that specifies
data sanitization methods

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for secure erasure of
sensitive information

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from storage media.

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Now, the DoD 5220.22-M method

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requires overriding
all addressable storage

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and indexing locations on the drive

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three times, with zeros, with ones

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and with random characters,

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and then verifies all
the writing procedures.

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Now, just a little note there, you see

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on the bottom that solid state drives

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may not be effectively sanitized

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using this standard and may require

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a manufacturer-specific utility.

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But what if we want to just get rid

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(laughs) of the media, right?

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We wanna destroy the media that

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that data is written on.

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Well, we have four options: shredding,

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pulverizing, pulping and burning.

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Now, shredding is physically breaking

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the media into pieces.

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Pulverizing is reducing media to dust.

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Pulping is chemically altering the media.

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And then burning is
incinerating the media.

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So maybe we wanna really take it

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to its final end and we just wanna get rid

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of that media totally, right?

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We could shred, sometimes
you'll hear the word shearing,

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pulverize, pulp or burn.

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But very often, you're going

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to outsource that destruction.

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There are a number of
third-party companies

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that actually do all the destruction work.

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But if you are going
to outsource that work,

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you wanna make sure that you receive

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a Certificate of Destruction.

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Now, a Certificate of Destruction

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is gonna be issued by commercial services

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upon destruction of the media.

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And that Certificate of Destruction,

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at a minimum, should include

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date of destruction;

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the description of the media,

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including a serial number,

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if that's appropriate; the method

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of destruction, burning, shredding,

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pulping, pulverizing; who witnessed it;

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and the company name, address

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and other contact information.

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And that, my friends, brings us

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to a three-second challenge.

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Five challenge questions,
three seconds each.

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You know how to do it.

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A residual representation of data.

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One, two, three.

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And that's gonna be our data remanence.

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A clearing technique that overwrites

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addressable storage multiple times.

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One, two, three.

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And that's gonna be disk sanitization,

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also known as disk wiping.

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Number three, vendor proof of destruction.

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One, two, three.

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And that's our Certificate of Destruction.

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Number four, rules that
dictate the data sets

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that must be kept and for how long.

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One, two, three.

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That's gonna be your retention policy.

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And lastly, number five,

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the process of reducing media to dust.

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All right, this is one of those
four destruction techniques.

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One, two, three.

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And that's gonna be pulverizing.

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I hope you did great on those.

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Let's do a security-in-action

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about confidential data.

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Research published in 2019

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by security firm Rapid7

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revealed how problematic

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discarded technology can be.

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The researcher, Josh
Frantz, bought 85 devices

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for $650 at a second-hand store and found

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over 366,300 files,

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including images and documents.

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And after an analysis of each device,

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Frantz found email
addresses, date of birth,

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Social Security numbers
and credit card numbers,

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driver's license numbers,
even passport numbers.

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So my question to you is
how could this exposure

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00:11:33,840 --> 00:11:34,863
have been avoided?

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00:11:35,760 --> 00:11:37,230
Should that information have been there?

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We know definitely (laughs) not.

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00:11:39,030 --> 00:11:40,380
So what could have happened?

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00:11:40,380 --> 00:11:42,540
How could have that exposure been avoided?

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00:11:42,540 --> 00:11:43,740
Go ahead and put me on pause

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00:11:43,740 --> 00:11:45,993
and note some controls, then come on back.

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00:11:48,810 --> 00:11:50,970
Well, the owners should have sanitized

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the drive, right, or the
drives before disposal.

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00:11:55,740 --> 00:11:58,110
Now, alternately, the
owners could have used

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00:11:58,110 --> 00:12:00,660
a third-party service
to destroy the drives

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by burning, shredding,

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00:12:02,430 --> 00:12:04,923
pulping or pulverizing.

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00:12:06,660 --> 00:12:09,150
And if none of the above
are feasible, right,

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then the hard drives should be removed

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from the devices, right,
and securely stored

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prior to donating or selling a device.

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So either you wanna sanitize it.

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You can do disk wiping, disk sanitation.

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We could destroy those drives.

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Or if you really can't do any of those,

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well, you need to make sure

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that you're not sending systems

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to a second-hand store or donating them

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00:12:30,840 --> 00:12:32,790
to a nonprofit or to a school

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with the drives in there.

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You wanna make sure that
you remove the drives

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and you securely store the drives

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because you need to protect

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any information that's on there.

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Doing that, my friends,
security-in-action.

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All right, there's your word cloud.

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Make sure you are comfortable
with all of these terms.

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00:12:48,270 --> 00:12:49,740
You know what they mean,

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00:12:49,740 --> 00:12:51,930
you could speak to them,
you could teach them.

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And then, when you're ready,

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head on over to our next quiz.