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The
task of identifying assets that need to be protected
is a less glamorous aspect of information security.
But unless we know these assets, their locations and
value, how are we going to decide the amount of time,
effort or money that we should spend on securing the
assets? by Avinash Kadam
In
this series on Information Security Management System,
we have so far discussed Security policy writing and
Security organization structure. Security policy is
essential, since it shows the management's commitment
to the subject of information security, and establishes
an outline giving clear direction in this matter. Security
organization creates an administrative infrastructure
defining roles and responsibilities of various participants
who are entrusted with the responsibility of implementing
and monitoring various aspects of information security.
The task of identifying assets that need to be protected
is a less glamorous aspect of information security.
But unless we know these assets, their locations and
value, how are we going to decide the amount of time,
effort or money that we should spend on securing the
assets?
The major steps required for asset classification and
controls are:
A. Identification of the assets
B. Accountability of assets
C. Preparing a schema for information classification
D. Implementing the classification schema
A. Identification of assets
What are the critical assets? Suppose your corporate
office was gutted in a major fire. Coping with this
level of disaster will depend on what critical information
you previously backed up at a remote location. Another
nightmarish scene is that a hacker entered your network
and copied your entire customer database. What impact
will this have on your business?
Identifying
the critical assets is essential for many reasons. You
will come to know what is critical and essential for
the business. You will be able to take appropriate decisions
regarding the level of security that should be provided
to protect the assets. You will also be able to decide
about the level of redundancy that is necessary by keeping
an extra copy of the data or an extra server that you
should procure and keep as a hot standby.
Next question that we need to ponder upon is: What exactly
is an information asset? Is it the hardware, the software,
the programs or the database?
We can broadly classify assets in the following categories:
1. Information assets
Every piece of information about your organization falls
in this category. This information has been collected,
classified, organized and stored in various forms.
Databases: Information about your customers, personnel,
production, sales, marketing, finances. This information
is critical for your business. It's confidentiality,
integrity and availability is of utmost importance.
Data files: Transactional data giving up-to-date information
about each event.
Operational and support procedures: These have been
developed over the years and provide detailed instructions
on how to perform various activities.
Archived information: Old information that may be required
to be maintained by law.
Continuity plans, fallback arrangements: These would
be developed to overcome any disaster and maintain the
continuity of business. Absence of these will lead to
ad-hoc decisions in a crisis.
2. Software assets
These can be divided into two categories:
a) Application software: Application software implements
business rules of the organization. Creation of application
software is a time consuming task. Integrity of application
software is very important. Any flaw in the application
software could impact the business adversely.
b) System software: An organization would invest in
various packaged software programs like operating systems,
DBMS, development tools and utilities, software packages,
office productivity suites etc.
Most of the software under this category would be available
off the shelf, unless the software is obsolete or non-standard.
3. Physical assets
These are the visible and tangible equipment and could
comprise of:
a) Computer equipment: Mainframe computers, servers,
desktops and notebook computers.
b) Communication equipment: Modems, routers, EPABXs
and fax machines.
c) Storage media: Magnetic tapes, disks, CDs and DATs.
d) Technical equipment: Power supplies, air conditioners.
e) Furniture and fixtures
4. Services
a) Computing services that the organization has outsourced.
b) Communication services like voice communication,
data communication, value added services, wide area
network etc.
c) Environmental conditioning services like heating,
lighting, air conditioning and power.
B. Accountability of assets
The next step is to establish accountability of assets.
This is not difficult for the tangible assets like physical
assets. Usually the organization will have a fixed assets
register maintained for the purpose of calculating depreciation.
A more difficult task is establishing ownership for
the information assets. There will be a number of users
for these assets. But the prime responsibility for accuracy
will lie with the asset owner. Any addition or modification
to the information asset will only be done with the
consent of the asset owner. For example, any changes
to customer information will be done with the knowledge
and consent of the marketing head. Information technology
staff will probably make the changes, physically. But
ownership clearly lies with the business head who has
the prime responsibility for the content in the customer
database.
Using these criteria, we have to identify the actual
owners of each of the information assets. This is also
an important step for one more reason. Only an owner
of the asset will be able to decide the business value
of the asset. Unless the correct business value of the
asset is known, we cannot identify the security requirement
of the asset.
The next step is identifying owners of the application
software. Application software implements the business
rules. As such the business process owner should be
the owner of application software. But the responsibility
of maintaining application software to accurately reflect
business rules will be vested with the application developers.
As such, the accountability for application software
should be with the application development manager.
System software ownership could be with the appropriate
persons within the IT team. The owner of these assets
will be responsible for maintaining all the system software
including protecting the organization against software
piracy.
Assets valuation
What is the value of an asset? Like beauty, which is
in the eyes of the beholder, an asset's value is best
known to the asset owner. It may not be merely the written
down value. A more realistic measure is the replacement
value. How much is it going to cost if the asset has
to be acquired today? Accurate valuation of an information
asset is a tricky task. Due care must be taken. A seemingly
small item may be immensely difficult to replace today.
True value of the asset will lead us to identify realistic
measures needed for protection of the asset.
C. Preparing a schema for classification
The next task is to create classification levels. The
criteria for the classification of assets could be:
1. Confidentiality: Can the information be freely distributed?
Or do we need to restrict it to certain identified individuals?
2. Value: What is the asset value? Is it a high value
item, costly to replace or a low value item?
3. Time: Is the information time sensitive? Will its
confidentiality status change after some time?
4. Access rights: Who will have access to the asset?
5. Destruction: How long the information will be stored?
How can it be destroyed, if necessary?
Each asset needs to be evaluated against the above criteria
and classified for easy identification. Let us look
at each category for classification.
Confidentiality could be defined in terms of:
a) Confidential: Where the access is restricted
to a specific list of people. These could be company
plans, secret manufacturing processes, formulas, etc.
b) Company only: Where the access is restricted
to internal employees only. These could be customer
databases, manufacturing procedures, etc.
c) Shared: Where the resources are shared within
groups or with people outside of the organization. This
could be operational information and contact information
like the internal telephone book to be shared with business
partners and agents.
d) Unclassified: Where the resources are publicly
accessible. For example, the company sales brochure
and other publicity material.
Classification based on value could be high, medium
or low value. A detailed explanation should be prepared
giving the reasoning for this classification. A critical
component costing a few rupees may be a very high value
item as it is not easily available and could stop the
production of a high cost item.
Access rights need to be defined for individuals as
well as groups. Who is cleared to access confidential
information in the organization? And who decides the
access rights? Logically, it will be the asset owner
who will decide these access rights.
Destruction should be a scheduled and controlled activity.
The information that is no longer needed by the company
but which could still be useful to competitors, should
be destroyed as per a pre-decided schedule and methoddepending
on the confidentiality classification. For information
recorded on hard disk, mere deletion of files does not
obliterate information. A more stringent procedure like
multiple overwriting may be needed.
Classification schema should lead to an implementable
structure. It should be simple to understand and identify.
D. Implementation of the classification schema
The real test of classification schema is when it is
implemented. Information is a fluid resource. It keeps
changing its form. The implementation should lead to
a uniform way of identifying the information so that
a uniform protection could be provided.
Let us take an example. A company's business plan is
a confidential document. Let us trace its journey in
the corporate world.
The plan will be discussed behind closed doors, known
to only a few senior members. In the next step the final
plan will be prepared and stored on the MD's computer
or that of his secretary. A soft copy of this plan would
be sent by email to all executives who need to refer
to it. The hard disk of every computer where the plan
is stored will also have a backup copy on floppy or
other media. Each member will no doubt print it and
keep a hard copy folder for reference. An extra copy
will also be prepared using the copying machine. If
the email is not available, the plan would be sent by
fax, post or courier.
So the 'confidential' plan is now distributed across
the organization, available on the hard disks of computers
belonging to each secretary and each senior executive.
You get the general idea. If this can happen to confidential
information, imagine how easy it is to get hold of other
types of information. The information explosion has
given rise to proliferation of information in every
nook and corner of the organization.
A practical implementation of classification schema
thus becomes very important. The classification label
should not give an easy way of identification, which
could be misused. It should provide the right amount
of protection.
In the example given above, each and every asset where
the confidential information is residing or transiting
through will have to be given the same classification
level as that of the information itself.
It may be desirable to altogether avoid transmission
of confidential documents in soft copy format, for example
as an attachment to email. Only a restricted number
of hard copies should be circulated. If it is necessary
to carry the soft copies, everyone should be instructed
to encrypt information for transmission and storage,
and to memorize their passwords and keep them secret.
Asset classification is thus the key to various security
controls that need to be implemented for asset protection.
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