Chapter 1 information assurance and security

A.M.T COLLEGE
DEPARTMENT OF INFORMATION TECHNOLOGY
Information Assurance and Security

COURSE OUTLINE
•Course title:-Information Assurance and Security
Course code:-ITec4132
Target Group: B.Sc. 4rd
year IT students
Year/Semester: year: IV, Semester: I
Instructor: Garedew Balgo
Email: garedew32@gmail.com
Phone: 0910632619
Lecture: Friday 4:30-6:30 at local time

Chapter 1
Cryptography and Network Security

Introduction
Computer data often travels from one
computer to another, leaving the safety of its
protected physical surroundings.
Once the data is out of hand, people
with bad intention could modify or fake
your data, either for enjoyment or for
their own benefit.

What is IAS?
Information assurance and security
(IAS) is the management and protection
of information, data, and knowledge.
 It combines the fields of information
assurance and information security:

Information assurance
Focuses on protecting information and
systems by ensuring their availability,
confidentiality, integrity, authentication,
and nonrepudiation.
It also involves managing risks related
to the use, storage, processing, and
transmission of information.

Information security
Focuses on developing tools,
technologies, and other measures to
secure information from unauthorized
access, use, disclosure, disruption,
modification, or destruction.

Some examples of IAS topics include:
•Cybersecurity
•Data privacy
•Information risk management
•Cryptographic techniques
•Security policies and compliance
•Network security
•Cloud security
•Internet of Things security

Cryptography is the practice of encoding
or hiding information so that only the
intended recipient can read it.
It has been used for thousands of years and
is still used in computer passwords, bank
cards, and ecommerce.
The technology is based on the
essentials of secret codes, that protects our
data in powerful ways.

What is the difference among Computer,
Network and Internet Security?
1. Computer Security - generic name for the
collection of tools designed to protect data and to
stop hackers.
2. Network Security - measures to protect data during
their transmission.
3. Internet Security - measures to protect data
during their transmission over a collection of
interconnected networks.

Security Attacks, Services and Mechanisms
To assess the security needs of an organization
effectively, the manager responsible for security
needs some systematic way of defining the
requirements for security and characterization of
approaches to satisfy those requirements.

1. Security attack – Any action that compromises the
security of information owned by an organization.
2. Security mechanism – A mechanism that is designed
to detect, prevent or recover from a security attack.
3. Security service – A service that enhances the
security of the data processing systems and the
information transfers of an organization.
The services are intended to counter security attacks and
they make use of one or more security mechanisms to
provide the service.

Basic Concepts
Cryptography :-The art or science
encompassing the principles and methods of
transforming an understandable message into
one that is meaningless, and then
retransforming that message back to its
original form.

Plaintext The original intelligible message
Cipher text The transformed message
Cipher An algorithm for transforming an
intelligible message into one that is
unintelligible by transposition and/or substitution
methods
Key Some critical information used by the cipher,
known only to the sender& receiver
Encipher (encode) The process of converting
plaintext to cipher text using a cipher and a key

Decipher (decode) : the process of converting cipher
text back into plaintext using a cipher and a key.
Cryptanalysis : The study of principles and methods
of transforming an unintelligible message back into an
intelligible message without knowledge of the key. also
called code breaking
Cryptology : is the science of secure
communications.
Code : An algorithm for transforming an intelligible
message into an unintelligible one using a code-book

Cryptographic systems are generally classified
along 3 independent dimensions:
1.Type of operations used for transforming
plain text to cipher text: All the encryption
algorithms are based on two general principles:
A. Substitution, in which each element in the
plaintext is mapped into another element, and
B. Transposition, in which elements in the plaintext
are rearranged.

•Cryptography creates messages
with hidden meaning; Cryptanalysis
is the science of breaking those
encrypted messages to recover their
meaning.

2.The number of keys used
If the sender and receiver uses same key
then it is said to be symmetric key (or) single
key (or) conventional encryption.
If the sender and receiver use different keys
then it is said to be public key encryption.

3.The way in which the plain text is processed
A. A block cipher processes the input and block of
elements at a time, producing output block for each
input block.
B.A stream cipher processes the input elements
continuously, producing output element one at a
time, as it goes along.

Stream ciphers convert one symbol of plaintext
directly into a symbol of cipher text.
Block ciphers encrypt a group of plain text
symbols as one block.
Simple substitution is an example of stream cipher.

Cryptanalysis
There are various types of cryptanalytic
attacks based on the amount of information
known to the cryptanalyst.
A. Cipher text only – A copy of cipher text alone is
known to the cryptanalyst.
B. Known plaintext – The cryptanalyst has a
copy of the cipher text and the corresponding
plaintext

C. Chosen plaintext – The cryptanalysts gains
temporary access to the encryption machine.
D. Chosen cipher text – The cryptanalyst
obtains temporary access to the decryption
machine, uses it to decrypt several string of
symbols, and tries to use the results to deduce
the key.

Next: Steganography
Steganography is the practice of hiding a message within
another file, such as an image, video, or audio file.
Steganography is the practice of concealing information
within another message or physical object to avoid
detection.
Steganography can be used to hide virtually any type of
digital content, including text, image, video, or audio
content.
The goal is to make the hidden message difficult to detect.

Drawbacks of steganography
1. Requires a lot of overhead to hide a relatively
few bits of information.
2. Once the system is discovered, it becomes
virtually worthless.

Types of steganography
•Image steganography
• Hides information within a digital image without changing its appearance.
•Text steganography
• Hides information within a text file. This can include changing the format of
the text.
•Video steganography
• Hides information within a video file.

•Audio steganography
•Hides information within an audio file.
•Network steganography
•Hides information within network protocols.
•Steganography can be used to conceal information without
making it traceable. The intended recipient is the only one
who should be able to understand the message.

Security Services
The classification of security services are as follows:
1. Confidentiality: Ensures that the information in a computer
system and transmitted information are accessible only for
reading by authorized parties.
2. Authentication: Ensures that the origin of a message or
electronic document is correctly identified, with an assurance
that the identity is not false.
3. Integrity: Ensures that only authorized parties are able to
modify computer system assets and transmitted information.
 Modification includes writing, changing status, deleting,
creating and delaying or replaying of transmitted messages.

4. Non-repudiation: requires that neither the sender
nor the receiver of a message be able to deny the
transmission.
5. Access control: Requires that access to information
resources may be controlled by or the target system.
6. Availability: Requires that computer system assets
be available to authorized parties when needed.

Security Mechanisms
One of the most specific security mechanisms in
use is cryptographic techniques.
Encryption or encryption-like transformations of
information are the most common means of
providing security.

Some of the mechanisms are
1. Encipherment
2. Digital Signature
3. Access Control

Security Attacks
There are four general categories of attack which are listed
below.
1. Interruption: -An asset of the system is destroyed or
becomes unavailable or unusable.
This is an attack on availability e.g., destruction of piece
of hardware, cutting of a communication line or Disabling of
file management system.

2. Interception: -An unauthorized party gains access
to an asset. This is an attack on confidentiality.
Unauthorized party could be a person, a program or
a computer.
e.g., wiretapping to capture data in the network, illicit
copying of files

3. Modification: -An unauthorized party not only
gains access to but tampers with an asset. This is an
attack on integrity. e.g., changing values in data file,
altering a program, modifying the contents of messages
being transmitted in a network.

4. Fabrication: -An unauthorized party inserts
counterfeit objects into the system. This is an
attack on authenticity. e.g., insertion of
spurious message in a network or addition of
records to a file.

Enterprise Security
What is Enterprise Security?
Enterprise security consists of the strategies and procedures
an organization uses to defend itself from bad actors.
Security mechanism dealing with providing
confidentiality, integrity, authentication, authorization
and non-repudiation related to the entire organization's
computing resources.

What is Enterprise
An enterprise is a business organization that produces goods
or services
A project or undertaking that is especially difficult,
complicated, or risky.

Enterprise security refers to a comprehensive set of
strategies, policies, technologies, and processes used by an
organization to protect its information assets, employees, and
operations from unauthorized access, ensuring the
confidentiality, integrity, and availability of critical data, often
including measures to prevent cyber threats and comply with
relevant regulations; essentially, it's the practice of
safeguarding an organization's digital assets across all levels of
the company through various security measures.

Key points about enterprise security:
•Holistic approach:/ሁለንተናዊ አቀራረብ
It encompasses both physical and digital security measures,
including network security, endpoint security, access control,
data encryption, and user education.
• Protecting the CIA /Confidentiality, Integrity, and
Availability/triad:
The primary goal is to maintain the confidentiality, integrity,
and availability (CIA triad) of sensitive information.

•Internal and external threats:
Enterprise security aims to defend against threats from both
external hackers and potentially malicious internal
employees.
•Compliance considerations:/ተገዢነት ግምት
Organizations must often implement security measures to
comply with industry regulations and data privacy laws.


Example elements of enterprise security:
Firewalls: To control network traffic and prevent
unauthorized access
Anti-malware software: To detect and block malicious
programs

Identity and access management (IAM): To control user
access to systems based on their roles and permissions
Data encryption: To protect sensitive data in transit and at
rest
Security awareness training: To educate employees about
cyber threats and best practices
Incident response plan: To effectively handle security
breaches and minimize damage

Cybersecurity is the use of technologies,
processes, and controls to protect systems,
networks, and data from cyber attacks.
 It aims to reduce the risk of unauthorized access
to systems and data.

Why is Cyber security Important?
Cyber security is important because it encompasses
everything that pertains to protecting our sensitive data,
personally identifiable information (PII), protected health
information (PHI), personal information, intellectual
property, data, and governmental and industry information
systems from theft and damage attempted by criminals and
adversaries.

Cyber security risk is increasing, driven
by global connectivity and usage of
cloud services, like Amazon Web
Services, to store sensitive data and
personal information.

Chapter 1 information assurance and security

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