CS-7303/CS-6303 Cyber
Crime and Security/
TE-7116 Cyber Security
Sir Syed University of Engineering & Technology, Karachi
Dr. Waeej Haider, DoCS&IT

Roadmap
 Computer Security
 Cyber Security
 Attacks
 Mutual Trust
 Network Security
 Computer Security
2

Background
 Information Security requirements have changed
in recent times (due to attacks on sensitive info.)
 Traditionally provided by physical and
administrative mechanisms
 Computer use requires automated tools to
protect files and other stored information
 Use of networks and communications links
requires measures to protect data during
transmission 3

Definitions
 Computer Security - generic name for the
collection of tools designed to protect data and
to thwart hackers
 Network Security - measures to protect data
during their transmission
 Internet Security - measures to protect data
during their transmission over a collection of
interconnected networks
5

Computer Security
 Can be elaborated as:
 The protection afforded to an automated
information system in order to attain the
applicable objectives of preserving the
integrity, availability and confidentiality of
information system resources (includes
hardware, software, firmware,
information/data, and telecommunications)
6

Cisco Public
© 2013 Cisco and/or its affiliates. All rights reserved. 7
Cybersecurity is the protection of internet-connected
systems such as hardware, software and data from cyber-
threats. The practice is used by individuals and enterprises to
protect against unauthorized access to data centers and
other computerized systems.
Farrukh Nizami
AIT CEP

Key Security Concepts
8

Examples of Security
Requirements
 confidentiality – student grades
 integrity – patient information
 availability – authentication service
 authenticity – admission ticket
 non-repudiation – stock sell order
9

Aspects of Security
 consider 3 aspects of information security:
 security attack
 security mechanism (control)
 security service
 note terms
 threat – a potential for violation of security
 vulnerability – a way by which loss can
happen
 attack – an assault on system security, a
deliberate attempt to evade security services
10

Attacks, Services and
Mechanisms
 Security Attack: Any action that compromises
the security of information.
 Security Mechanism: A mechanism that is
designed to detect, prevent, or recover from a
security attack.
 Security Service: A service that enhances the
security of data processing systems and
information transfers. A security service makes
use of one or more security mechanisms. 11

Threat Actors
Threat Actors
 Threat actors are individuals or groups of individuals
who perform cyberattacks. They include, but are not
limited to:
• Amateurs (self-taught)
• Hacktivists (use of computer-based techniques such
as hacking as a form of civil disobedience to promote
a political agenda or social change)
• Organized crime groups
• State-sponsored groups
• Terrorist groups
 Cyberattacks are intentional malicious acts meant to
negatively impact another individual or organization.

Security Attacks
14
Learning Assignment: In the notes (below)

Security Attacks
 Passive attacks: are in the nature of
eavesdropping on, or monitoring of,
transmissions
 Goal of the opponent is to obtain
information that is being transmitted
 Active attacks: involve some modification
of the data stream or the creation of a
false stream 15

Passive Attack - Interception
•This is an attack on confidentiality 16

Passive Attack: Traffic Analysis
Observe traffic pattern
17

Active Attack: Interruption
Block delivery of message
•This is an attack on availability 18

Active Attack: Fabrication
Fabricate message
•This is an attack on authenticity 19

Active Attack: Replay
20

Active Attack: Modification
Modify message
This is an attack on integrity 21

Handling Attacks
 Passive attacks – focus on Prevention
• Easy to stop
• Hard to detect
 Active attacks – focus on Detection and
Recovery
• Hard to stop
• Easy to detect
22

23
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential
 The Consequences of a Security Breach
• Not feasible to prevent every attack
• Attackers will always find new ways
• Ruined reputation, vandalism, theft,
revenue lost, damaged intellectual property
 Security Breach Example - LastPass
• An online password manager
• Stolen email addresses, password reminders,
and authentication hashes
• Requires email verification or multi-factor
authentication when logging in from an unknown device
• Users should use complex master password,
change master password periodically, and beware of
phishing attacks
Organizational Data
The Impact of a Security Breach

24
© 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential
 Internal Security Threats
• Can be an employee or contract partner
• Mishandle confidential data
• Threaten the operations of internal servers or network
infrastructure devices
• Facilitate outside attacks by connecting infected USB
media into the corporate computer system
• Accidentally invite malware onto the network
through malicious email or websites
• Can cause great damage because of direct access
 External Security Threats
• exploit vulnerabilities in network or
computing devices
• use social engineering to gain
access
The Profile of a Cyber Attacker
Internal and External Threats

25
© 2020 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

Levels of Impact
 can define 3 levels of impact from a
security breach
 Low
 Moderate
 High
26

Low Impact
 The loss could be expected to have a limited adverse
effect on organizational operations, organizational
assets, or individuals.
 A limited adverse effect means that, for example, the
loss of confidentiality, integrity, or availability might
 (i) cause a degradation in mission capability to an
extent and duration that the organization is able to
perform its primary functions, but the effectiveness of
the functions is noticeably reduced;
 (ii) result in minor damage to organizational assets;
 (iii) result in minor financial loss; or
 (iv) result in minor harm to individuals. 27

Moderate Impact
 The loss could be expected to have a serious adverse
effect on organizational operations, organizational
assets, or individuals.
 A serious adverse effect means that, for example, the
loss might
 (i) cause a significant degradation in mission
capability to an extent and duration that the
organization is able to perform its primary functions,
but the effectiveness of the functions is significantly
reduced;
 (ii) result in significant damage to organizational
assets;
 (iii) result in significant financial loss; or
 (iv) result in significant harm to individuals that does
not involve loss of life or serious, life-threatening
injuries.
28

High Impact
 The loss could be expected to have a severe or
catastrophic adverse effect on organizational operations,
organizational assets, or individuals.
 A severe or catastrophic adverse effect means that, for
example, the loss might
 (i) cause a severe degradation in or loss of mission
capability to an extent and duration that the
organization is not able to perform one or more of its
primary functions;
 (ii) result in major damage to organizational assets;
 (iii) result in major financial loss; or
 (iv) result in severe or catastrophic harm to individuals
involving loss of life or serious life threatening injuries.
29

 The following describes some of the ways
through which any information systems
can be attacked.
a. Social Engineering
b. Viruses / Trojan Horses / Worms
c. Denial of Service (DoS)
d. IP Spoofing
e. Replay Attack
How to do an Attack
30

Social Engineering
 Social engineering is a technique used by attackers
to gain system access or information by exploiting
the basic human instinct to be helpful.
 Social engineering exploit are successful because
the targeted enterprise lacks an awareness
program to educate employees of their security-
related duties and responsibilities.
 A simple phone call by an intruder to a target
posing as a network support guy and asking her
username and password to rectify a non existing
problem.

Viruses / Trojan Horses / Worms
 Virus is malicious code that can plant itself into
operating systems and programs and modify them.
 Trojan-horse is a virus that is hidden inside a
legitimate software. Once the software is installed
or downloaded, the malicious code does its thing.
 Worm is industry nomenclature for a self-contained
program that will replicate itself across a network,
infecting each server and workstation it can
access.

Denial of Service (DoS)
 An attack that targets resources within the network
with the intention of reserving resource and
keeping legitimate users from gaining access.
 During a SYN attack, an enemy workstation will
generate a flood of session requests using bogus
IP addresses.
 The target server begins reserving resources for
each request while waiting for the completion of
the TCP/IP handshake process.
 The expected reply from the enemy workstation
never comes but the reserved resources results in
the denial of service for the legitimate user.

IP Spoofing
 IP spoofing is accomplished when an outside
hacker uses a discovered IP address to gain
access of a trusted environment from outside the
network.
 A hacker can obtain a valid IP address in a variety
of ways such as social engineering.

Replay Attack
 A replay attack occurs when a hacker intercepts a
communication between two parties and replays
the message.
 For instance, a hacker might intercept a credit card
transaction between a consumer and a Web site.
The hacker then replays the transaction multiple
times resulting in multiple debits to the consumers
credit account.

Security Service
 enhance security of data processing systems
and information transfers of an organization
 intended to counter security attacks
 using one or more security mechanisms
 often replicates functions normally associated
with physical documents
• which, for example, have signatures, dates; need
protection from disclosure, tampering, or
destruction; be notarized or witnessed; be
recorded or licensed
36

37
Security Services
 Confidentiality (privacy)
 Authentication (who created or sent the data)
 Integrity (has not been altered)
 Non-repudiation (the order is final)
 Access control (prevent misuse of resources)
 Availability (permanence, non-erasure)
 Denial of Service Attacks
 Virus that deletes files
37

Security Services
 X.800:
“a service provided by a protocol layer of
communicating open systems, which ensures
adequate security of the systems or of data
transfers”
 RFC 2828:
“a processing or communication service
provided by a system to give a specific kind of
protection to system resources”
38

Security Services (X.800)
 Authentication - assurance that communicating
entity is the one claimed
 have both peer-entity & data origin authentication
 Access Control - prevention of the
unauthorized use of a resource
 Data Confidentiality –protection of data from
unauthorized disclosure
 Data Integrity - assurance that data received is
as sent by an authorized entity
 Non-Repudiation - protection against denial by
one of the parties in a communication
 Availability – resource accessible/usable 39

Security Mechanism
 a.k.a. control
 feature designed to detect, prevent, or
recover from a security attack
 no single mechanism that will support all
services required
 however one particular element underlies
many of the security mechanisms in use:
 cryptographic techniques
 hence our focus on this topic
40

Security Mechanisms (X.800)
specific security mechanisms: (May be
incorporated into the appropriate protocol layer in order
to provide some of the OSI security services)
 encipherment, digital signatures, access controls,
data integrity, authentication exchange, traffic
padding, routing control, notarization
pervasive security mechanisms:
(Mechanisms that are not specific to any particular OSI
security service or protocol layer)
 trusted functionality, security labels, event detection,
security audit trails, security recovery
41

Specific security mechanisms
Encipherment
 The use of mathematical algorithms to transform data into
a form that is not readily intelligible. The transformation
and subsequent recovery of the data depend on an
algorithm and zero or more encryption keys.
Digital Signature
 Data appended to, or a cryptographic transformation of, a
data unit that allows a recipient of the data unit to prove
the source and integrity of the data unit and protect
against forgery (e.g., by the recipient).
Access Control
 A variety of mechanisms that enforce access rights to
resources.
Data Integrity
 A variety of mechanisms used to assure the integrity of a
data unit or stream of data units. 42

Cont….
Authentication Exchange
 A mechanism intended to ensure the identity of an entity
by means of information exchange.
Traffic Padding
 The insertion of bits into gaps in a data stream to
frustrate traffic analysis attempts.
Routing Control
 Enables selection of particular physically secure routes
for certain data and allows routing changes, especially
when a breach of security is suspected.
Notarization
 The use of a trusted third party to assure certain
properties of a data exchange. 43

Pervasive security mechanisms:
Trusted Functionality
 That which is perceived to be correct with respect to
some criteria (e.g., as established by a security policy).
Security Label
 The marking bound to a resource (which may be a data
unit) that names or designates the security attributes of
that resource.
Event Detection
 Detection of security-relevant events.
Security Audit Trail
 Data collected and potentially used to facilitate a security
audit, which is an independent review and examination
of system records and activities.
Security Recovery
 Deals with requests from mechanisms, such as event
handling and management functions, and takes recovery
actions.
44

Model for Network Security
45

Model for Network Security
 using this model requires us to:
1. design a suitable algorithm for the security
transformation
2. generate the secret information (keys) used
by the algorithm
3. develop methods to distribute and share the
secret information
4. specify a protocol enabling the principals to
use the transformation and secret
information for a security service
46

Model for Network Access
Security
47

Model for Network Access
Security
 using this model requires us to:
1. select appropriate gatekeeper functions to
identify users
2. implement security controls to ensure only
authorised users access designated
information or resources
 note that model does not include:
1. monitoring of system for successful
penetration
2. monitoring of authorized users for misuse
3. audit logging for forensic uses, etc. 48

Summary
 topic roadmap & standards organizations
 security concepts:
 confidentiality, integrity, availability
 X.800 security architecture
 security attacks, services, mechanisms
 models for network (access) security
49