Computer Audit an Introductory

Barclay Simpson
Recruitment Consultants
An Introduction to
Computer Auditing

Index
1. INTRODUCTION
1.1 Purpose 2
1.2 Definition 2
1.3 Origins of Computer Audit 2
1.4 Change 2
1.5 Nature of Computer Audit 3
1.6 Computer Auditors 3
1.7 Scope 4
2. SYSTEMS UNDER DEVELOPMENT
2.1 Background 5
2.2 Development of New IT Applications 5
2.3 IT Application Controls 7
3. LIVE APPLICATIONS
3.1 Background 10
3.2 Application Controls 10
3.3 General IT Infrastructure Controls 10
4. IT INFRASTRUCTURE
4.1 Background 12
4.2 IT Environment 12
4.3 Infrastructure Areas 12
4.3.1 Physical Security 12
4.3.2 Contingency Planning 13
4.3.3 Logical Access Controls 14
4.3.4 Change Control 15
4.3.5 Operating Systems 16
4.3.6 Telecommunications 16
4.3.7 Cryptography 17
4.3.8 Computer Operations 17
4.3.9 Databases 18
4.3.10 Storage Media 18
5. AUDIT AUTOMATION
5.1 Background 19
5.2 Audit Tools 19
5.3 Administration Tools 19
GLOSSARY OF TERMS 20
B A R C L AY S I M P S O N 1
AnIntroductiontoComputerAuditing

1. Introduction
B A R C L AY S I M P S O N2
1.1 Purpose
The aim of these notes is to give potential computer
auditors an overview of the main activities of
computer audit and the role of the computer auditor.
They have been written to assist candidates who are
planning to attend an interview for a position in
computer audit but have a limited knowledge of the
subject. For those from either an audit, business or
information technology (IT) background seeking a
move into computer audit, these notes will provide
useful background reading.
Whilst any organisation that has agreed to interview a
candidate who has limited experience of computer
auditing will judge them accordingly, there is
substantial scope for candidates to improve their
chances by demonstrating that they have done some
research and are conversant with the basic principles.
Further, as it is increasingly difficult to distinguish
between IT and business areas, many organisations
now require that all business auditors have an
awareness of computer audit. These notes, therefore,
should assist business auditors in obtaining a greater
appreciation of computer auditing.
Given the diversity of IT, it is not possible within a
document of this type to be specific about computer
audit in particular sectors or in relation to specific
hardware or software. The basic principles of
computer audit should be common to all sectors and
to most types of hardware and software.
1.2 Definition
One of the most important factors to consider when
discussing computer audit is that the term “computer
audit” can mean many different things to different
people. What may be regarded as computer auditing
in one organisation, and very much the realm of the
specialist computer auditor, may be undertaken by
business auditors in another similar organisation. For
example, computer audit may be restricted to
auditing systems software in one organisation, whilst
areas such as auditing systems under development
may be the responsibility of the business auditor.
Similarly, in some organisations, it is not uncommon
for the role of computer audit to be extended to
include the review of clerical procedures and the
production of compliance based audit work
programmes for field auditors, thereby providing a
wider systems audit service.
There are no hard and fast rules as to what
constitutes computer audit. Often, similar sized
organisations operating in the same sector may have
different approaches to computer audit. Even where
there appears to be commonality in the scope of
audit areas, there can be significant variations in the
depth of auditing undertaken. An audit of an
operating system in one organisation may require
between 5 and 10 man-days, whilst in another, the
same operating system may be subject to a more
detailed examination lasting several months.
1.3 Origins of Computer Audit
The absence of a common definition of computer
audit may, in part, be due to the relative newness of
computer audit. The history of traditional auditing or
inspection can be traced back many hundreds of
years. In contrast, computer audit is a relatively
recent development. It was not until the late 1970’s
that the majority of major organisations in the UK
established a computer audit capability for the first
time.
The use of IT in business is also a relatively recent
development. The father of modern day computing is
generally regarded as being Charles Babbage, who
produced his Difference Calculator in 1833. It was
not until the outbreak of the Second World War and
the widespread development of valve technology,
that the 1st Generation computers were used. Even
then, it was many years later that they became
commonplace in business.
1.4 Change
A key feature of many organisations today is change.
Although not necessarily the driver of change, IT is
invariably an intrinsic component and much of the
change would not be possible without IT. IT has had
a major impact on social, economic and political
factors throughout the world. Not only has it led to
the creation of new professions but it has also
revolutionised others, such as office work, or, when
combined with robotics, manufacturing industries.
Computer audit operates in a climate of constant and
rapid change. Computer auditors are continually
faced with the prospect of faster, smaller and cheaper
IT systems. An analogy that is frequently used to
describe the rapid development of IT, is if aviation
had developed at the same rate, man would have
landed on the moon in 1922. IT is a dynamic area
which in turn, requires a dynamic and flexible
control structure.

The rapid development of IT is perhaps best
indicated by the relative absence of specific IT
legislation, which, in England and Wales, is largely
based upon precedent established over many years.
The only specific IT legislation in the UK at present is
the Data Protection Act 1984 and the Computer
Misuse Act 1990, both of which have been subject to
considerable interpretation by the Courts. Both
pieces of legislation are security and control related.
1.5 Nature of Computer Audit
Although an IT system may achieve the same end
result as a manual system, the way in which it does
so, and hence the level of security and control
required, can differ considerably. There are a
number of significant risks associated with the
processing of IT systems. It is important, therefore,
that high standards of security and control are
maintained to minimise the potential impact on the
organisation.
Computer fraud and abuse can have a detrimental
effect on an organisation. Periodic surveys
undertaken by organisations such as the NCC
(National Computing Centre) and the Audit
Commission indicate the following common instances
of computer fraud and abuse:
• unauthorised disclosure of confidential
information
• unavailability of key IT systems
• unauthorised modification/destruction of software
• unauthorised modification/destruction of data
• theft of IT hardware and software
• use of IT facilities for personal business
When considering computer audit, it should be noted
that the basic control objectives and principles do not
change. The manner in which those objectives are
achieved, however, does change fundamentally.
Specifically, there is a need for greater preventative
controls rather than a reliance on the more detective
and corrective control mechanisms which would
usually be found in manual systems. The
development of on-line real time systems, where the
immediacy of processing can result in millions of
pounds being transferred away in a funds transfer
system, requires a robust level of security.
1.6 Computer Auditors
It was not until the late 1970’s that most
organisations in the UK established a computer audit
capability. This primarily arose out of the need to
provide business auditors with independent data
from the IT system. This in turn progressed to a
wider review of the IT applications and infrastructure
to provide an assurance that the organisation’s assets
were protected and that suitable security and control
mechanisms were in place. The high level of
technical knowledge required resulted in the birth of
the computer auditor.
It is important when considering computer audit to
note that it is an integral part of the overall audit
activity. It is usually separated to enable specialised
security and control issues to be dealt with more
effectively and to make better use of specialist staff.
Computer auditing, therefore, is a means to an end
rather than an end in itself. There is always a
temptation when dealing with IT to become
engrossed in the technical complexities of an
operating system or application and to ignore the
business realities of the organisation. Risk based
computer auditing, integrated as appropriate with
business audit, is essential if computer audit is to add
value to the organisation and to deliver the effective
service demanded of it by senior management.
Over the years, the role of the computer auditor has
changed to being more consultative and value
adding. Clearly, where a new system is being
developed, it is more cost effective for audit
comments to be provided prior to a system being
implemented, when improved security and control
features can be included more easily and cheaply.
Similarly, although computer auditors regularly
undertake audits of say logical access controls, there
is considerable scope for computer auditors to be
involved in the design of those components.
There is an issue of independence if the computer
auditor becomes involved in the design process as
this may be compromised if the same individual
subsequently audits that system. It is generally
recognised, however, that the costs of not getting
involved are so great that this is not an option. It is
unlikely, for example, that senior management will
be happy to receive an audit report just after a new
IT system has gone live which details significant
security and control exposures.
The role of the computer auditor continues to
mature and develop. This is essential if computer

audit is to provide a value added service to the
business in the face of increasingly sophisticated
technology. A key challenge for computer auditors is
to keep up to date with the constant and rapid
developments in IT. Continuous training and
development is essential. Successful computer
auditing is based upon a foundation of technical
excellence. Without this, computer auditors are
limited in their ability to audit effectively and to
provide a valuable service to the organisation.
It should also be noted that the role of the computer
auditor can, in some areas, overlap with that of the
computer security function and this can cause
confusion. It is essential to clearly define respective
responsibilities so that unnecessary duplication is
avoided. Essentially, the role of the computer
security section is to assist users in developing
security solutions and to administer that security on a
day to day basis. The role of the computer auditor is
to provide senior management with an independent
and objective assurance as to the level of security
applied within the IT environment. As an integral
part of the audit process, computer auditors will also
provide advice and it is in this area that duplication
and overlap may arise.
1.7 Scope
The following sections of these notes describe the
main areas of computer audit activity:
• systems under development
• live applications
• IT infrastructure
• audit automation
The extent to which these areas are reviewed and the
depth to which they are examined will vary. Key to
the performance of audit work is a comprehensive
risk based evaluation which should determine the
amount of audit resource required and should also
assist in determining an assessment of a satisfactory
level of security and control.
A brief outline of the involvement of the computer
auditor has been provided for each area. The
purpose of this outline is to give an indication of the
audit considerations rather than to provide an
exhaustive list. Readers are advised to refer to
appropriate text books where additional information
is required, specifically, “Computer Auditing” by Ian J
Douglas and the “CIPFA Computer Auditing
Guidelines” by CIPFA.
Acknowledgement
Barclay Simpson would like to acknowledge
the assistance of Graham Burggy QiCA MIIA
ACIB, in the completion of these notes.
Graham Burggy is an experienced Computer
Audit Manager who has worked in computer
audit for three major financial services
organisations.
No part of these notes may be reproduced or
transmitted in any form or by any means without
prior permission.
©Barclay Simpson Associates Limited.

2. Systems Under Development
2.1 Background
“There is nothing more difficult to plan, more
doubtful of success, nor more dangerous to manage
than the creation of a new system” Machievelli.
The development of a new computer system
represents an area of potentially significant risk to an
organisation. New computer systems are developed
to meet a variety of business needs, whether they be
to meet new legal requirements, to maintain or
enhance profitability, to improve efficiency or to
reduce costs. The failure of a new system could
have a major impact on an organisation’s future
viability and well being.
A review of an organisation’s financial statements will
usually indicate that, with minor exceptions, the
development of IT systems is also one of the
organisation’s major areas of investment.
The potential sources of a new IT application are
many and varied. A number of factors, such as cost,
time constraints and availability of a skilled resource,
will determine which source is the most appropriate
for a particular organisation. Options include:
• a bespoke development by an in-house IT team
• a package solution from a software house
• a bespoke development by a software house
• joint bespoke development (partnership) by a
software house and the in-house IT team
• end-user development
Computer audit activity within systems under
development is focused on two main areas:
• the manner in which a new IT application is
developed
• the adequacy of security and control within an IT
application
2.2 Development of New IT
Applications
It is important to ensure that new IT applications are
developed in a controlled manner so that they
perform only those functions that the user requires
and that adequate security and control is included.
The manner in which a new IT system is developed
is generally considered under two main headings:
• project management
• the systems development life cycle
2.2.1 Project Management
Project Management is concerned with delivering a
solution on time, within budget and to the
appropriate level of quality. Project management as
an activity is not confined to IT and many of the
basic principles have been developed in other
industries, notably the construction industry.
The basic principles of good project management are:
• clearly defined management responsibility
• clear objectives and scope
• effective planning and control
• clear lines of accountability
There are a variety of project management
methodologies in existence, such as PRINCE (Project
in Controlled Environment), which in turn may be
supported by an ever increasing range of project
management tools, such as Project Manager
Workbench (PMW) and MS-Project. The precise
requirements of project management methodologies
vary and frequently methodologies may be
customised to meet the specific needs of an
organisation.
In spite of the widespread availability of such
methodologies and tools, research has shown that the
majority of IT projects are not implemented on time,
within budget or to the appropriate level of quality.
Typical components in a project management
methodology include:
Organisation
This is to ensure that senior management are
committed to the project and to enable issues to be
resolved promptly. A standard framework for the
direction and management of a project should be
established, which generally involves committees
such as a Steering Committee and the appointment of
specific personnel such as a Project Manager or
Project Sponsor.
Planning
This is to ensure that work activities are addressed at
an appropriate level of detail, that resource
requirements are identified and that risks are properly
evaluated. Comprehensive planning is the key to
successful project management and forms the basis of
subsequent project control. Typically, a project will
be broken down into a number of sub-projects, each
with a number of specific stages.

Control
This is to ensure that potential problems can be
identified and that the ongoing viability of the project
can be continuously monitored.
Project control generally consists of financial controls
such as budgets and time controls such as milestones,
which enable the status of a project to be measured.
Frequently, a regime of more subjective controls will
also be established, such as internal and quality
assurance reviews, supported where necessary by
external reviews undertaken by specialist consultancy
organisations.
Computer Audit Involvement in Project
Management
The computer auditor should be involved in the audit
of project management. The purpose of this
involvement is to provide an objective view to project
management and an independent appraisal to
accountable senior management, that an adequate
system of project management is in place.
Key areas of audit interest are to assess whether:
• an effective project team has been set up to
ensure that responsibilities are clearly defined,
that senior management are involved and that
issues can be raised
• comprehensive and sufficiently detailed plans
have been prepared together with an assessment
of the extent to which they are achievable and
whether they cover all areas
• effective mechanisms have been established to
continuously monitor project progress in order to
obtain an assurance that senior management is
provided with timely information so that variances
from the plans can be investigated and the
appropriate action taken
2.2.2 Systems Development Life Cycle
The systems development life cycle is concerned with
the formal development of an IT application and
aims to ensure that a new IT solution is:
• developed in a controlled manner
• adequately documented
• maintainable in the future
• developed efficiently and securely
• meets the user’s requirements
IT applications have traditionally been developed in a
mainframe computer environment, in a low level
programming language such as Assembler, or a high
level programming language such as COBOL, by
specialised programmers working to a design
produced by systems analysts. Package solutions are
also used extensively for common applications such
as payroll. As with project management, a variety of
methodologies have been developed to assist in this
process, the most widely known of which is probably
SSADM (Structured Systems Analysis and Design
Methodology).
The precise definition of stages in a systems
development life cycle will vary according to the
development process and methodology being used.
In many ways the stages of a life cycle are consistent
with the basic principles of TQM (Total Quality
Management). Typical stages are:
Project Initiation/Feasibility Study
The purpose of this phase is to progress an initial
idea to a stage where a project can be formally
defined. Once defined, the feasibility of this
proposal and the cost benefit can be determined.
Analysis and User Requirements
The aims of this phase are to confirm the project
objectives and scope, to identify and classify the
required data and to identify and prioritise business
requirements.
Design
The aim of this phase is to complete a logical and
detailed technical design of the system which meets
the user’s requirements.
Build
This involves programming and testing the system.
Testing will consist of a number of components, such
as unit testing, link testing, systems testing and user
acceptance testing.
Implementation
The aims of this stage are to plan and co-ordinate all
the activities needed to ensure that the new (or
amended) system can be successfully moved into
production in a manner which will maximise the
delivery of benefits while keeping disruption to a
minimum.
Post Implementation Review
The aim of this stage is to review the development to
determine any lessons for the future. In practice, this
stage is all too frequently ignored.

Increasingly, IT applications are being developed by
alternative processes. IT applications, for example,
are being developed by end users, whether relatively
simple spreadsheets which generate key MIS for
strategic decision making or more complex
developments in languages such as MS-Access and
FoxPro. Even within the more formal and structured
IT development areas there is a move towards
modern methods of developing IT applications.
These include:
• CASE (Computer Aided Software Engineering) -
this is a working environment consisting of
programs and other developmental tools that help
managers, systems analysts, programmers and
users to automate the design and implementation
of programs and procedures. Common CASE
tools include IEF, from Texas Instruments, and
Foundation, from Andersen Consulting
• Object Orientation - a program is viewed as a
collection of discrete objects that are self
contained collections of data structures and
routines that interact with other objects. C++ is
an object orientated version of the C
programming language
• Prototyping - here systems are developed
on-screen interactively with the user, typically in a
fourth generation language (4GL). Several
iterations may be produced until an acceptable
product is achieved. From this, a full production
system can be developed
• Rapid Application Development (RAD) - unlike
prototyping which is a development technique to
create a throwaway version of a product, RAD is
an end to end development life cycle. It is based
upon the premise that 80% of the solution can be
achieved in 20% of the time it would take to
develop 100% of the solution. The most widely
known RAD methodology is DSDM (Dynamic
Systems Development Method)
A key impact of these newer approaches is that
traditional development documentation may not be
available. A more interactive and ongoing
involvement may be necessary although this in turn
may create issues of resourcing and scheduling.
Audit Involvement in the Systems Development
Life Cycle
Early involvement in the audit of systems under
development is essential. The purpose of this
involvement is to provide an assurance to project
management, user management and accountable
senior management of the organisation that the
application has been developed in a secure and
controlled manner. Some types of development may
cause greater concern than others, such as end-user
developments where the users are not skilled in the
disciplines of developing IT systems.
The primary area of audit focus should be the design
phase where an assurance and advice on the
adequacy of proposed controls can be provided. A
strong presence in the testing phase is also
recommended to ensure that the proposed controls
are robust and workable.
The computer auditor should seek an assurance that:
• user requirements have been fully understood and
confirmed
• the IT system, and any associated manual
processes, meet those requirements
• the development approach and methodology are
appropriate for that development and provide for
a thorough consideration of risks and the
inclusion of controls
• adequate documentation is available which
explains the workings of the system
The computer auditor may also undertake limited
compliance testing to ensure that deliverables are
produced in accordance with the approved
methodology.
2.3 IT Application Controls
Within an IT application it is important to ensure that
satisfactory levels of security and control are
implemented to meet identified risks. Application
controls generally fall under two main headings:
• application specific controls
• general IT infrastructure controls
2.3.1 Application Specific Controls
This is concerned with controls within the IT
application and consists of the following:
Input Control
Input controls will be necessary to ensure that all
data entered is authorised, complete, accurate and
entered only once. Typically, a combination of
manual and automated controls will be required to

achieve this. These include validation checks, range
checks and segregation. The system should also
provide a suitable mechanism that records sensitive
or critical activities by individual users and enables
the production of evidence of processing.
Processing Controls
Processing controls will be necessary to ensure that
transactions are processed completely, accurately and
in a timely fashion. A variety of controls will be used
to achieve this, for example, reconciling input control
totals with subsequent output, validating the integrity
and reasonableness of automatically generated
transactions and generating calculations automatically
from the appropriate authorised standing data.
Output Controls
Output controls will be necessary to ensure the
completeness, accuracy and availability of application
output, whether it be in a paper form, or as
electronic data. On printed output, controls such as
sequence numbers and page numbers will be used to
ensure completeness.
Procedures
Procedures should be prepared which contain
adequate management and supervisory controls and
checks. In some instances, separate user guides may
be prepared for the application, although usually they
will be incorporated in a departmental procedures
manual.
Computer Audit Involvement in Application
Specific Controls
Early involvement in the development of a new IT
application is essential if the computer auditor is to
add value to the process and to safeguard the
organisation’s interests. It is obviously easier and
cheaper to incorporate improved security and control
features at the design stage of a new system rather
than when it has gone live. Research suggests that it
only costs 50p to implement a recommendation at
the design phase, but £1500 when it has gone live.
In practice, the actual cost can be far higher as the
system may not get the necessary priority and
resource, and even if it does, the organisation runs
the risk of the exposure until the weakness can be
corrected.
As the application is in the process of being
developed the computer auditor will have to rely on
a review of available documentation and discussions
with relevant IT and business personnel to obtain an
assurance as to the adequacy of security and control.
Whilst it is not possible during the development
phase to conduct detailed audit testing, formal test
plans should be reviewed to ensure that controls are
being adequately addressed and consideration could
even be given to setting up specific security and
control test plans.
Key areas of interest for the computer auditor
include:
Input
• are input documents authorised by an appropriate
person(s)
• is adequate segregation in place
• does input validation include the following checks:
• data within valid limits
• data one of valid codes
• data compared to existing items on file
• check digits
• balancing - e.g. agrees to batch total, journal
totals to zero
Processing Controls
• are changes to the calculation/formulae properly
controlled, tested and authorised
• are key calculations checked
Output Controls
• is printed output held and distributed securely
• are reasonable checks of output performed
• are logical controls over access to on-line output
reports adequate
• is there a schedule of when output is due, which
should be linked to an operations schedule to
ensure that the necessary programs are run on
time
Procedures
• have procedures manuals been prepared which
adequately define controls and checks
• have the procedures been tested before the
system goes live
2.3.2 General IT Infrastructure Controls
When considering application controls, general IT
infrastructure controls should also be evaluated. The

rationale behind this is that there is limited value in
providing an evaluation on the adequacy of security
and control within the application if no assurance can
be provided about the IT environment on which it
runs.
The basic areas to be considered under general IT
infrastructure controls are detailed in Section 4 of
these notes. In this instance, they are considered at a
lower, application specific level of detail. The extent
to which general IT infrastructure controls need to be
considered will obviously vary from application to
application. If an application is to run on an existing
mainframe, then a reliance can be placed upon
existing mainframe infrastructure controls. It will
only be necessary to consider the areas specific to
that application, e.g. which users are to be allowed
access, what type of access will be allowed or what
additions need to be made to the existing mainframe
contingency plan. If, however, the application is to
run on a new LAN for example, then additional areas
will need to be considered, e.g. should a logical
access control package be installed, who will be
responsible for its administration and will a new
contingency plan be necessary?
The general IT infrastructure controls to be
considered include:
• physical security
• contingency planning
• logical access control
• program change control
• operating system
• telecommunications
• storage media
• databases
• cryptography
• computer operations
Computer Audit Involvement in General IT
Infrastructure Controls
If the new application will run on an existing
mainframe installation, a reliance will be placed upon
existing computer audit work to assess the security
and control mechanisms in place. The audit effort in
this instance will focus on the application specific
aspects, e.g. has the application been included in the
contingency plan and have appropriate logical access
control rules been established. If, however, the
application requires a new computer installation, say
a LAN, then these areas will need to be considered in
more detail.

3. Live Applications
3.1 Background
Many organisations are dependent upon the
availability of IT systems to such an extent that it is
true to say that for them, no IT means no business.
It is important, therefore, that the IT applications
within an organisation are subject to a periodic risk
based evaluation of security and control. The
rationale behind a periodic evaluation is that:
• IT applications are dynamic and changes to the
system will be necessary. Although such changes
may be subject to audit evaluation, it is usually
the case that changes are made over a period of
time, usually without audit review, and the
application system may differ considerably from
that originally implemented. This may impact on
the effectiveness of security and control
• the control environment surrounding the
application may change. Associated manual
processes, for example, may change significantly,
as the dramatic de-layering of middle
management in many organisations has shown
• live data may indicate the need for additional
security and control. As the application is used in
a live environment, specific processing conditions
or types of data may come to light which the
existing security and control structure does not
accommodate
• risks may change and increase or decrease,
rendering the existing security and controls
inappropriate. For example, the number of
customers may increase substantially, or data may
be used for new purposes such as strategic
decision making
In a similar way to the audit of systems under
development, effective security and control are
achieved by a combination of application specific and
general IT infrastructure controls.
3.2 Application Controls
This is concerned with controls within the application
- see Section 2 - Systems Under Development for
details. For ease of reference, the headings of this
Section are summarised here:
Input Controls
• processing controls
• output controls
• procedures
Computer Audit Involvement in Application
Specific Controls
The key issue of audit involvement in live
applications is to determine who will undertake the
review. In many organisations, computer auditors
will perform a live review of IT applications, whilst in
others, live applications may be viewed as a business
area and therefore the responsibility of a business
auditor. Increasingly, a joint approach is being
adopted by many organisations where the IT
application forms part of a wider scope audit of the
business area and enables a more integrated and
complete review to be undertaken.
The frequency of the periodic review is also
important. Risk should be the key factor in
determining frequency and hence, importance to the
organisation. A variety of risk assessment
methodologies are available for this purpose from the
simple and subjective to the more formal and
structured such as CRAMM (Computerised Risk
Analysis and Management Methodology).
The audit work required for a live application review
is very similar to that undertaken for a system under
development with one main exception. When
auditing an application under development, there is
little opportunity for detailed audit testing. Audit
work will focus on evaluating the adequacy of
security and control using discussion and a review of
technical documentation. The testing phase of the
project may allow some scope for control testing, but
this is artificial. With a live application review, there
is considerable scope for audit testing, as live data
will be available together with other documentary
evidence such as error logs.
Effective use of CAATS (See Section 5 - Audit
Automation) can also be made in live application
reviews. Interrogation software can be used to
identify exceptional conditions in data or to produce
a sample of records for testing.
3.3 General IT Infrastructure
Controls
As with systems under development, when
considering application controls, general IT
infrastructure controls should also be considered.
These areas include:
• physical security
• contingency planning

• logical access control
• program change control
• operating systems
• telecommunications
• storage media
• databases
• cryptography
• computer operations
Computer Audit Involvement in General IT
Infrastructure Controls
The approach to the review of general IT
infrastructure controls is very similar to that detailed
in Section 2 - Systems Under Development. Again,
the main difference is that there is considerably more
scope for detailed audit testing in a live review.

4. IT Infrastructure
4.1 Background
IT Infrastructure is a generic term which describes
components such as computer hardware, systems
software or telecommunications which provide a
processing platform for business applications.
IT infrastructure represents an area of potentially
significant risk to the organisation as the overall
security and control of its business applications is to
a large extent dependent upon the level of integrity,
availability and confidentiality within the IT
infrastructure.
4.2 IT Environment
In considering IT infrastructure, it should be noted
that there is no such ideal as a standard computer
installation. In some organisations, IT hardware may
be located in a purpose built computer centre, where
responsibility for its operation and maintenance is in
the hands of specialist personnel, such as computer
operators, systems programmers and operations
analysts. In other organisations, IT hardware may
also be located in a purpose built computer
installation, but responsibility for its operation and
maintenance may be vested in a smaller number of
personnel who will perform a wider range of duties.
In some organisations, IT hardware may be located in
a user environment, where responsibility for such
activities as software upgrades and back-ups is simply
the part-time responsibility of one or two individuals.
Traditional computer audit text books invariably refer
to three distinct types of computer: mainframe, mini
and micro. Whilst such terms do exist, in practice it
is very difficult to distinguish between them. What is
regarded by one organisation as a mainframe
computer located in a purpose built computer centre,
may be viewed as a mini computer by another and
could be located in an office environment. The
situation is further complicated by extensive
telecommunications networks and the use of client
server environments, where several desktop machines
are connected to a central server which contains the
data and programs. This move towards a distributed
computing environment has increased the potential
exposure of most organisations as the control
environment increasingly becomes dependent on the
weakest link in the network.
The impact of these variances is that the control
environment over identical IT infrastructure
components can differ significantly. When
considering IT infrastructure, a computer auditor may
come across a wide range of environments,
configurations, hardware and software. As ever, risk
should be the critical factor in determining the
amount of audit effort required and the most effective
audit approach to be adopted.
4.3 Infrastructure Areas
The following areas are of interest to the computer
auditor in considering IT infrastructure, although the
amount of work required under each heading will
vary. For example, a physical security review of a
purpose built computer centre housing a large IBM
mainframe computer may require a specific audit of
several weeks duration. A review of the physical
security aspects of a user based PC, however, may
only, require a few hours work and could be
incorporated into a larger scope audit.
4.3.1 Physical Security
Accidental or deliberate physical damage to IT
equipment could damage the software and data of
the organisation. Given the large capital investment
made by organisations in IT, not only could this
result in a significant financial cost to the
organisation, but also the non-availability of the
system could have a major impact on the well-being
of the organisation. It is essential that effective
physical security arrangements are in place to protect
the IT environment from accidental or malicious
damage.
The term physical security can be further considered
under the following headings:
Physical Access
This is concerned with restricting access to IT
infrastructure to authorised persons only. Physical
access will initially consist of perimeter security
which may be achieved by the use of walls and
fencing, supported as appropriate by such controls as
CCTV or security guards. Within the building,
various IT infrastructure components such as
telecommunications and central processing units
should be segregated and an access control system
should be installed to restrict the access of
unauthorised personnel. Typically, this will involve
some form of card based access control system,
although more sophisticated systems using
biometrics, such as finger print scanning may be
found. Comprehensive intruder detection systems,
incorporating a combination of contact breakers and

passive infra red detectors should be used, connected
directly to a central monitoring station.
Fire Protection
Fire represents a key area of risk to IT infrastructure
and good fire protection systems are essential. Fire
protection is generally considered under the
following headings:
• fire prevention systems - these include no
smoking policies, good housekeeping practices
such as the prompt removal of waste paper or the
use of fire proof materials
• fire detection systems - these include the use of
smoke and fire detectors in ceiling and floor voids
and manual fire alarms, which should be
connected directly to a central monitoring station
• fire extinguishing systems - traditionally Halon
has been used as an effective extinguishing agent
although environmental concerns mean that this is
no longer appropriate. Other types of
extinguishing system include CO2 and fine spray
water sprinkler systems. The systems should be
capable of manual and automatic activation and
also be linked to an automatic power down of
the IT equipment
Power Supplies
The availability of quality power supplies is essential
to the efficient running of IT infrastructure, otherwise
data corruption and equipment damage can occur. A
wide range of devices are available to smooth out
potential fluctuations in the quality of the power
supply, known as spikes and troughs, such as an
uninterruptable power supply (UPS) system. Again,
dependent on risk, it may also be appropriate to
have a back-up power supply in the event of a mains
failure. This will usually consist of a back-up
generator and a short term battery powered supply.
Air Conditioning
As with power supplies, IT infrastructure is sensitive
to its operating environment. Controls are needed to
ensure the quality of air and the temperature.
Typically, air conditioning systems will be installed,
together with good housekeeping procedures, such
as avoiding the shredding of paper in the vicinity of
IT equipment.
Flood Protection
Flooding can be caused by both internal and external
sources and the impact can be significant, particularly
if the water is contaminated, in which case
equipment may be damaged beyond repair. Water
detection systems should be installed and where
possible, water supplies should be routed away from
IT equipment. Care should also be given to the
siting of IT equipment so that it is protected from
local hazards, such as being below ground level in an
area prone to flooding.
Computer Audit Involvement in Physical Security
In considering physical security, the computer auditor
should be aware that in some areas this can be a
specialist field. In these circumstances, e.g. fire
systems, computer auditors should seek the advice of
specialist organisations such as the Fire Brigade.
Careful risk analysis is necessary to determine the
amount of audit work required in this area and to
ensure that the level of control is commensurate with
the degree of risk to the organisation.
The computer auditor should ensure that effective
security and control mechanisms are in place so that
the computer installation is physically secure and is
adequately protected against potential destruction and
physical loss. Audit work will rely heavily on
observation and discussion, together with a review of
available documentation such as access control logs,
and associated manual procedures, such as those for
allowing access to visitors.
4.3.2 Contingency Planning
Such is the dependence on IT by an increasing
number of organisations that the non-availability of
their IT infrastructure could have a profound impact
on the well being of the organisation, if not on its
continued survival. Research has indicated that of
those organisations suffering a major IT failure, the
majority will be out of business within two years.
Effective physical security controls can do much to
prevent or restrict the potential impact of a disaster,
but it is essential that effective and tested contingency
plans are in place to enable the organisation to
survive such an eventuality. Contingency plans
should cater for various levels of IT infrastructure
failure, from strike action by key IT staff, to a major
disaster such as a fire or flood which completely
destroys the IT capability.

In terms of larger IT installations, a number of
different strategies can be adopted for contingency.
These include:
• hot standby - a dedicated site is available to
resume processing from the main site almost
instantaneously. This site will have identical IT
hardware, software and data to the main site
• warm standby - an alternative, similarly
configured site is available to resume processing,
but which will require several hours to set up,
e.g. to load back-up data. Typically, these sites
are provided by specialist disaster recovery
services such as CDR (Computer Disaster
Recovery) or Guardian Computer Services and
may be shared by several users
• cold standby - where premises are available
which must first be equipped out with hardware,
etc. before they can be used. Typically these
range from an empty warehouse to a spare office
or a portacabin
• reciprocal agreements - arrangements with
other organisations operating similar equipment
are also an option, although in reality, these tend
to be impractical in today’s IT dependent business
environment
Clearly the specific needs of the business will
determine which is the most appropriate solution to
its needs. For smaller IT environments, variations of
these strategies can be adopted.
It is important to ensure that IT contingency plans do
not exist in isolation of the business. Business
requirements, ideally in the form of a wider business
resumption plan, should be clearly identified and
should provide the basis for subsequent contingency
planning. Regular and thorough testing of the plan is
essential if an assurance is to be obtained as to its
effectiveness. IT is such a dynamic area and regular
testing helps to ensure that potential problems are
identified and resolved.
Computer Audit Involvement in Contingency
Planning
Ideally, computer auditors should be involved in the
development of a contingency plan and in the testing
process. The objective of this involvement is to
ensure that the plan is comprehensive, up to date,
and meets the requirements of the business. The
computer auditor should consider whether a
contingency plan exists and if it is documented, up to
date and regularly tested. Areas to consider include
ensuring that the correct back-ups are taken, stored
off-site and that the back-up hardware and software
environment will meet the needs of the business.
4.3.3 Logical Access Control
The nature of IT is such that the emphasis of the
traditional control environment has moved to one of
prevention rather than detection. Most organisations
now use on-line or real time systems where data is
updated and transactions are initiated immediately.
Logical access controls, therefore, are a key feature of
IT infrastructure in that they provide the ability to
identify and authenticate users and thereby control
access to and usage of the system.
The basic purpose of logical access controls is to
restrict authorised users to performing authorised
activities from authorised locations via only
authorised channels. It is essential, to achieve an
effective balance between having too much security
and allowing too much flexibility and access for the
users.
In operating systems such as VMS from DEC,
Windows NT from Microsoft and OS/400 from IBM,
security functionality is integrated within the
operating system software. In others, such as the
large IBM operating system, MVS, separate logical
access control software will have to be implemented
to achieve the required level of security - Top Secret
and ACF2 from Computer Associates and RACF from
IBM are the most common packages available for this
purpose. In some operating systems, notably the
various flavours of UNIX, security functionality is
included within the operating system software, but it
may need to be supplemented by third party
packages such as BOKs, to achieve the required level
of security.
The basic components of logical access control
systems include:
• environmental controls - where system-wide
options/parameters are set. These include the
initial security level, whether protection is to be
extended to magnetic media, password options
such as the number of invalid attempts allowed
and the enforcement of password changes
• user controls - where restrictions are put on
who can access the system and from where.
Usually, there will be a number of users in the
system who are privileged; that is they have

special attributes which enable them to perform
special actions. In UNIX, for example, the
privileged user is known as “Root” and has access
to all system resources
• resource controls - where the protection for
resources such as databases are created, e.g.
when is access to this database to be allowed, is
the access to be read only and from what
terminal?
Logical access control systems can be customised
although this can have a significant effect on the
security of the IT system. The customisation is
achieved by a series of parameters or values which
determine how the software will work, e.g. how
many logon attempts will a user be allowed? Exits
are also included which enable an organisation to
develop its own logical access controls code.
The administration of logical access control is
particularly important. Specifically, it is advisable to
segregate the administration of logical access control
from other operational activities and to provide for
regular checking of the administrator’s activities, e.g.
the independent review of audit trails.
A key issue of logical access control is that with the
proliferation of IT systems, many users are required
to hold several User-IDs and passwords. Inevitably,
this results in users keeping a record of them, so
compromising security. It is technically feasible to
implement a single sign-on system where a user is
authenticated at the point of entry and only has to
sign-on once. Such systems, however, do not
necessarily provide for a secure single sign-on as
frequently, passwords are distributed in clear text.
There are problems of password synchronisation and,
invariably, the available products do not cater for all
of the IT platforms that an organisation is likely to
use.
Computer Audit Involvement in Logical Access
Control
The basic objective of a logical access control review
is to establish whether controls over access to
systems, data, software and resources are adequate.
Ideally, the computer auditor should be involved in
the initial design of the access control system when
appropriate advice and guidance on the level of
security can be provided.
The computer auditor should review the access
control administration function to ensure adequate
segregation, procedures and checking of work. The
system-wide options and locally coded exits should
be reviewed to ensure that they do not compromise
security. Limited testing may be undertaken to
ensure that key databases and system resources are
sufficiently protected and that user’s access rights are
consistent with their operational duties. An important
consideration is to ensure that effective mechanisms
have been established to investigate potential and
actual breaches of IT security.
4.3.4 Change Control
Change is a common feature of the IT world. It is
important that effective control procedures are in
place to ensure that only authorised changes are
made to IT systems. Not only is there scope for the
accidental or deliberate inclusion of unauthorised
code (the so called Trojan horse or time bomb) but
change involves a degree of risk and it is necessary
to ensure, for example, that the right version of
software is actually implemented.
Formal change control systems are necessary to
ensure that changes to application software, systems
software, and even IT hardware, are adequately
tested, authorised and moved to live production in a
controlled manner. A variety of change control
software products are available to assist, notably CA-
Librarian and Endevor for IBM systems. Many
operating systems include basic change control
functionality, whilst a number of organisations
develop their own to meet specific needs. The basic
functions of this software are to:
• establish different logical environments for
programming, testing, quality assurance and live
program versions
• restrict access to program code
• provide version control over the program libraries
• provide an audit trail facility
Formal change control systems should accommodate
not only scheduled changes, but also the need for
emergency changes, whether they be software or
data. The basic principles of change control apply to
emergency changes, i.e. authorisation is required,
although detailed investigation, testing and
documentation of the change may be undertaken
after the event.

Computer Audit Involvement in Program Change
Control
The objective of the computer auditor is to obtain an
assurance that changes to applications and systems
software and hardware are adequately controlled.
The computer auditor should ensure that a change
control system is in place which accommodates both
scheduled and emergency changes. An assurance
should also be obtained that an authorisation
mechanism is in place, that adequate documentation
of the change is produced, that the integrity and
security of program versions is maintained and that
the implementation process provides for back-out
routines.
4.3.5 Operating Systems
An operating system is usually defined as a set of
programs which permit the continuous operation of a
computer. The software controls scheduling and
execution of application programs and use of
computer resources. Simplistically, the operating
system acts as the interface between the application
program, the user and the IT hardware. The security
and control of an operating system is a complex issue
and provides an area of potentially major risk to an
organisation.
The complexity, size and functionality of operating
systems varies enormously from one manufacturer to
another. Some operating systems may include
functionality, such as database management systems
and security software, whilst others will require
separate systems software to perform such tasks.
Some of the most well known operating systems
include MVS from IBM, which contains over 10
million lines of code, VMS from DEC and VME from
ICL. Whilst operating systems such as MVS, VMS and
VME are proprietary to that manufacturer and
dependent on its hardware, a few operating systems,
notably UNIX, are portable and can be run on a
range of manufacturers’ hardware. This portability,
however, may be limited, as invariably basic UNIX is
customised by each supplier to provide its own
features, such as AIX from IBM and HP-UX from
Hewlett Packard. In effect, these portable, or open
systems, become proprietary and dependent on a
specific manufacturer’s hardware.
The extent to which operating systems need to be
customised varies considerably, not only from one
operating system to another, but from organisation to
organisation, depending upon its specific
requirements. Usually, most operating systems will
have a series of parameters or values which
determine how the operating system will work. Exits
are also included which enable an organisation to
develop its own operating system code. This
customisation can have a significant effect on the
confidentiality, availability and integrity of IT
processing.
In larger organisations, running large complex
operating systems, it is not uncommon to have
personnel specifically responsible for fine tuning and
customising the operating system. Effective control
procedures are required over such personnel.
Computer Audit Involvement in Operating
Systems
The audit of operating systems is a complex and time
consuming area. In some instances, software is
available to assist in this process, such as CA-Examine
for MVS.
The basic objective of the computer auditor is to
ensure that the security and integrity of the operating
system has not been compromised. The auditor
should consider whether responsibility for the
maintenance of the operating system has been
established and that suitable procedures have been
documented. An effective change control system is
necessary to ensure that only authorised amendments
can be made to the operating system. The computer
auditor should also ensure that system initiation
procedures are established to prevent unauthorised
changes.
4.3.6 Telecommunications
The major development in computing in the last few
years has been the rapid expansion of
telecommunications. As a result, a vast amount of
data is regularly transmitted throughout the world
and with it there are significant security and control
exposures, specifically in terms of availability and
integrity.
There are many different types of telecommunications
networks, such as local area networks (LANs) which
are usually confined to individual offices and wide
area networks (WANs) which can span continents.
Telecommunications software is necessary to operate
these networks and to enable communication
between user terminals and the application program.
A vast array of network protocols are necessary and
several will be found in the same organisation,

whether for historical or specific business reasons (a
protocol is a set of standards to ensure data moves
efficiently around a network). Typical protocols
include IBM’s SDLC Synchronous Data Link Control
and TCP/IP (Transmission Control Protocol/Internet
Protocol).
Telecommunications software typically provides the
following functionality:
• controlling the flow of data in a network
• providing for recovery and resilience
• MIS on network performance and capacity
management
• security and cryptography functionality
• network administration tools
• network audit trails
Again, telecommunications is a very specialised area
possibly requiring the support of a separate team.
The number of staff required will vary from
installation to installation, and may comprise several
sections in large organisations running software such
as IBM’s SNA (Systems Network Architecture).
As with operating systems, telecommunications
software can be customised as appropriate by an
organisation. Exit points are also available to enable
user code to be implemented. Some
telecommunications software, such as CICS (Customer
Information Control System) also includes security
software features.
Computer Audit Involvement in
Telecommunications
The basic audit objective is to ensure that adequate
security and control is in place over the organisation’s
telecommunications networks. Initially, the computer
auditor must obtain network diagrams of all physical
and logical connections. The computer auditor
should ensure that telecommunications hardware,
such as front-end processors (FEPs) are physically
secure. Effective control should be exercised over the
addition or deletion of devices to the network and
documented procedures should govern the work of
the various personnel involved in the network. The
computer auditor should assess the adequacy of the
back-up arrangements and assess whether adequate
control is exercised over the use of diagnostic tools,
such as datascopes which could compromise network
integrity or confidentiality. Particular attention should
be paid to the existence of any dial-in connections.
4.3.7 Cryptography
The risks associated with the transmission of data
over extensive telecommunications networks (parts of
which may not be under the organisations direct
control) have created a need to take additional steps
to prevent the unauthorised/accidental corruption of
messages in transit, or a breach of confidentiality.
Cryptography can be used to ensure confidentiality,
integrity, non-repudiation and authenticity and
includes such techniques as encryption and digital
signatures. Military organisations and banking
institutions make extensive use of cryptography.
Encryption
Encryption is a widely used technique which involves
making information indecipherable to protect it from
unauthorised viewing or use, especially during
transmission or when it is held on removable magnetic
media. Encryption is usually based on a key(s)
without which the information cannot be decoded
(decrypted). The most widely used encryption system
is DES (Data Encryption Standard) although
increasingly this is being replaced commercially by
the more secure public key system RSA.
Message Authentication
Message authentication makes use of encryption to
create a digital signature which is appended to a
transaction. This does not scramble the data but any
difference in the digital signature at the receiving end
will indicate some form of message corruption.
Computer Audit Involvement in Cryptography
Cryptography is a very specialised and complex area
and a review of this requires a high degree of
specialised knowledge. Typically, in ensuring that
adequate controls are in place over authentication
and encryption, the computer auditor will wish to
ensure that encryption hardware is physically secure,
that audit trails are made of key change activity and
that the generation of keys is well controlled.
4.3.8 Computer Operations
Within any type of computer installation, personnel
are required to operate the IT systems. The tasks
undertaken, the number of personnel required and
the extent of automation involved may vary
significantly from one installation to another. Typical
operating tasks include:
• job scheduling
• operating IT hardware

• housekeeping
• recovery and back-up
Computer Audit Involvement in Computer
Operations
The basic objectives of the computer auditor are to
assess whether adequate controls are in place over
data preparation, the completeness of processing and
the dispatch of output. The computer auditor will
wish to ensure that adequate audit logs of operator
activity are maintained, that the computer room is
tidy, that there is an adequate segregation of duties
and that work is appropriately organised. The
computer auditor should also ensure that output is
securely controlled and that appropriate arrangements
exist for re-runs and that unwanted output is safely
disposed of.
4.3.9 Databases
A database may be defined as “a collection of inter-
related data which is organised so that, as far as
possible, it is independent of any specific application
and wherever possible, not duplicated”. A database
is a structured way of storing and managing data in a
consistent manner, which is independent of the
physical structure of the data. Data is arguably one
of the organisation’s most important resources and as
such it is essential that strong controls are in place
over its use.
There are two main types of database:
• hierarchical or CODASYL - hierarchical
databases have a “tree” structure, with a hierarchy
of nodes, the top node being the “root” node.
One of the most common examples of this type
of database is IMS (Information Management
System) from IBM
• relational - with relational databases, data is
modelled into logical records and relationships as
before, but entities become rows in a table and
attributes become columns. DB/2 from IBM is an
example of a widely used relational database
The database which holds the data is controlled by
software known as a database management system
(DBMS). The purpose of this system is to manage
the data in the most efficient form. All requests to
read, change, insert or delete data must be made
through the database management system. Logs are
also maintained of such actions. Usually, the
database management system incorporates security
software to control access to the data.
Computer Audit Involvement in Databases
The basic objective of the computer auditor is to
assess the integrity and availability of the database.
Key areas of interest are to restrict access and to
ensure a satisfactory segregation of duties between
the database administrator and other operation and
support functions. Local exits should be reviewed,
together with the various DBMS options to ensure
that security has not been compromised.
4.3.10 Storage Media
Most organisations operating sophisticated IT systems
will hold a vast quantity of data. In general, this will
be held on direct access storage devices (DASD) such
as fixed disks. In some instances, notably archive
data and back-up data, other media such as
cartridges, magnetic tapes or optical disks may be
used. Often, robotic devices such as cartridge
libraries are in use to automate the control of such
media, although manually administered tape libraries
will also be found.
The concentration of such a quantity of data in a
small number of locations poses potential risks to an
organisation. It is essential, therefore, that this data is
held securely, that it is protected from unauthorised
use and that adequate records of its use are
maintained. Specific procedures are required to
provide for the safe disposal of magnetic media, for
which devices such as degaussers may be used.
Computer Audit Involvement in Storage Media
The computer auditor should ensure that satisfactory
control is exercised over its use and storage and that
it is physically protected from accidental or deliberate
damage. The computer auditor should determine
what data is held on magnetic media and its
significance to the organisation. There will be a need
to ensure that authorisation mechanisms are in place
for the use of media and that procedures provide for
its correct labelling and cleaning.

5. Audit Automation
5.1 Background
In many organisations, the origins of computer audit
lie in the need for business auditors to obtain
independent data from the system and subsequently,
to obtain an assurance about the internal workings of
the IT system. Although audit automation still
represents a core activity of many computer auditors,
increasingly, this activity is being transferred to
business auditors. This transition has been facilitated
by the availability of more user friendly application
software. The role of the computer auditor in this
environment is to provide specialist expertise to the
business auditors, rather than perform the activity.
IT can deliver significant benefits to the audit process
in terms of: timeliness, efficiency, professionalism and
increased productivity.
Audit automation is generally considered under two
main headings:
• as an audit tool
• as an administration tool
5.2 Audit Tools
Audit automation, in this context, involves the use of
computer assisted audit techniques (CAATS) as an
integral part of an audit review to increase its overall
efficiency and effectiveness. CAATS are generally
categorised into those which review data and those
which review controls.
Those CAATS which review data generally involve
the extraction, examination and manipulation of data
by programs. Such techniques can enable the auditor
to gain an assurance as to the accuracy and integrity
of the data being reviewed and, by implication, the
strength or weakness of control. Those CAATS which
review controls look at the system rather than data
and provide the auditor with an assurance as to
whether or not controls exist and are functioning
effectively. By implication, this will cause the auditor
to question the accuracy and integrity of that data.
Traditional text books on computer audit usually refer
to a large range of CAATS. Although some of these
are used to varying degrees by some organisations, in
practice, interrogation software is the most widely
used CAAT.
5.2.1 Interrogation Software
Interrogation software involves the production of a
computer program to interrogate either system or
application data. Standard programming languages
such as COBOL may be used and generalised audit
software is also available from the accounting firms,
such as System 2190 from KPMG. Specific retrieval
software such as Easytrieve from SRA can also be
obtained. Increasingly, there is a large range of third
party software products available for the development
of CAATS. Some of the most widely known include:
• IDEA (Interactive Data Extraction & Analysis)
• ACL (Auditor Command Language)
• SQL (Structured Query Language - used with
relational databases)
• SAS (Statistical Analysis Software)
There is also a wide variety of other third party
software which can assist in an audit review, such as
CA-Examine for a review of the IBM MVS operating
system, or the Enterprise Security Manager from
Axent for a review of UNIX.
5.2.2 Embedded Data Collection
This is similar to interrogation software, but the
program logic is embedded within the live
application program or systems software.
5.2.3 Parallel Simulation
This involves the re-writing of a system and
processing data through it so that the results can be
compared to the live system.
5.2.4 Others
There are a variety of other tools, such as code
comparison software which can compare two files,
containing either data or program code, and highlight
differences.
5.3 Administration Tools
A large range of products is now available to assist in
the effective running of the internal audit function.
These can be developed in-house or acquired from
third party suppliers. In some instances, such as
planning software, generally available products such
as PMW can be used, although audit specific
products are increasingly becoming available. Not
only do such products simplify the administration of
the function, but they also provide a more
professional service for the organisation.
Typically products will be used for such areas as:
planning, risk assessment, time recording, electronic
working papers and presentations.

Glossary of Terms
MAN : Metropolitan Area Network - typically operates with a discrete
geographic location (i.e. a city)
MICR : Magnetic Ink Character Recognition - the recognition of
characters on paper by detecting the magnetic code on characters
Modem : Device that converts digital signals to analogue and vice
versa to enable computers to communicate across telephones lines
MS-DOS : Microsoft-Disk Operating System - single tasking, single
user operating system
MVS : Multiple Virtual Storage - IBM mainframe operating system
OCR : Optical Character Recognition - the recognition of printed
characters on paper by detecting patterns of dark and light
OOP : Object Orientated Programming
Operating System : The software responsible for controlling the
allocation and usage of hardware resources such as memory and
CPU
Oracle : A relational database product
OS/2 : A protected mode, virtual memory, multitasking operating
system from IBM based on the Intel x86 processors
Pascal : Concise procedural programming language
PMW : Project Manager Workbench - a project management tool
PRINCE : Project in Controlled Environment - a project management
methodology
RACF : Resource Access Control Facility - an access control software
product for mainframe computers, produced by IBM
RAD : Rapid Application Development - a development process to
speed up the development of IT systems
RISC : Reduced Instruction Set Computing - a type of
microprocessor that focuses on processing a relatively small set of
instructions rapidly, rather than handling a much wider array of
instructions
ROM : Read Only Memory - semiconductor based memory that
contains instructions or data that can be read but not modified
RSA : Public key encryption standard
Server : On a LAN, the computer running the administrative software
that controls access to all or part of the network and its resources
SSADM : Structured Systems Analysis and Design Methodology - a
systems development life cycle methodology
Structured Query Language (SQL) : A database tool used to
interrogate, update and manage relational database
Sybase : A relational database product
TCP/IP : Transmission Control Protocol/Internet Protocol - a set of
standards for telecommunications
Token Ring Network : A network topology that uses token passing
as a means of regulating traffic on the line
Top Secret : An access control software product for mainframe
computers, produced by Computer Associates
Trojan Horse : An apparently useful program that contains hidden
code, usually damaging
Ultrix : A version of the UNIX operating system from Digital
UNIX : A multi-user, multi-tasking operating system. Written in C it
is more portable and less machine specific than other operating
systems. The main versions are System V from AT&T and BSD from
the University of California, Berkeley
UPS : Uninterruptable Power Supply - equipment to smooth out
variations in the quality of the electricity supply
Virus : A program, usually harmful, that infects files, usually by
inserting copies of itself in those files
VME : Operating system from ICL
VMS : Operating system from Digital
VTAM : Virtual Telecommunications Access Method - an IBM product
to provide mainframe communication
Windows : A multi-tasking graphical user interface environment
from Microsoft that runs on MS-DOS based PCs
WORM : Write Once Read Many - a high capacity read only storage
device using optical disk
The following glossary is designed to give readers an understanding
of some of the more common acronyms which will be found in the
computer auditing arena.
ACF2 : An access control software product for mainframe computers,
produced by Computer Associates
AIX : The IBM version of the UNIX operating system
Application : A program which performs business functions such as
payroll
ASCII : American Standard Code for Information Interchange - a
code for representing characters in binary
Assembly Language : A low level language where one
programming instruction corresponds to one machine code
instruction
BS7799 : The British Standard Code of Practice for Information
Security Management
C : Programming language closely associated with UNIX
CAD : Computer Aided Design
CAM : Computer Aided Manufacturing
CASE : Computer Aided Software Engineering
CD-ROM : Compact Disk - Read Only Memory - large capacity
storage media using compact disks of varying sizes. These are read
only
CICS : Customer Information Control System - IBM product that
enables transactions entered at remote terminals to be processed
concurrently by user written application programs
Client Server Architecture : LANs that make use of distributed
intelligence to treat both the server and the workstations as
intelligent programmable devices
COBOL : COmmon Business Orientated Language - high level
English-like programming language
Compile : Process of preparing a “machine language” program from
a source language program such as COBOL
CP/M : A range of operating systems based on the Intel
microprocessors from Digital
CPU : Central Processing Unit - main intelligence of the computer
which processes instructions for execution
CRAMM : Computerised Risk Analysis and Management
Methodology - a risk assessment methodology
Database : A collection of inter-related data which is organised so
that, as far as possible, it is independent of any specific application
and wherever possible, not duplicated
DASD : Direct Access Storage Device
DB/2 : A relational database management system from IBM
DBMS : Database Management System
DES : Data Encryption Standard - widely used encryption standard
DIP : Document Image Processing - scanning of documents onto
optical disk
EBCDIC : Extended Binary Coded Decimal Interchange Code - a
code for representing characters in binary
EDI : Electronic Data Interchange - transfer of electronic trading
information through computer to computer communication
EFT : Electronic Funds Transfer - transfer of electronic funds through
computer to computer communication
Ethernet : Local area network using a bus topology
Expert System : Application program that solves problems by using
analytical rules and knowledge
FAST : Federation Against Software Theft - an organisation of
vendors who work to eliminate software theft
FORTRAN : FORmula TRANslator - the first high level computer
programming language used primarily in engineering and scientific
environments
GUI : Graphical User Interface - pictorial representation of
commands, files etc.
HP-UK : A version of the UNIX operating system from Hewlett
Packard
Ingress : A relational database product
Internet : A global network of networks connecting a range of
organisations
ISDN : Integrated Services Digital Network - a network that allows
voice transmissions to be mixed with data and video services
LAN : Local Area Network - a group of computers and other devices
spread over a relatively limited area and connected by
communications links
BARCLAY SIMPSON
Hamilton House, 1 Temple Avenue, Victoria Embankment, London EC4Y 0HA.
Tel: 0171 936 2601 Fax: 0171 936 2655 http://www.barclaysimpson.co.uk

Computer Audit an Introductory

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