Cr-1
Attached
Cryptography and Network Security:
Principles and Practice
Eighth Edition
Chapter 1
Information and Network Security
Concepts
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Cybersecurity (1 of 3)
Cybersecurity is the collection of tools, policies, security
concepts, security safeguards, guidelines, risk management
approaches, actions, training, best practices, assurance, and
technologies that can be used to protect the cyberspace
environment and organization and users assets.
Organization and users assets include connected computing
devices, personnel, infrastructure, applications, services,
telecommunications systems, and the totality of transmitted
and/or stored information in the cyberspace environment.
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Cybersecurity (2 of 3)
Cybersecurity strives to ensure the attainment and
maintenance of the security properties of the organization
and users assets against relevant security risks in the
cyberspace environment. The general security objectives
comprise the following: availability; integrity, which may
include data authenticity and nonrepudiation; and
confidentiality
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Cybersecurity (3 of 3)
Information Security
This term refers to preservation of confidentiality, integrity,
and availability of information. In addition, other properties,
such as authenticity, accountability, nonrepudiation, and
reliability can also be involved
Network Security
This term refers to protection of networks and their service
from unauthorized modification, destruction, or disclosure,
and provision of assurance that the network performs its
critical functions correctly and there are no harmful side
effects
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Security Objectives (1 of 2)
The cybersecurity definition introduces three key
objectives that are at the heart of information and network
security:
Confidentiality: This term covers two related
concepts:
Data confidentiality: Assures that private or
confidential information is not made available or
disclosed to unauthorized individuals
Privacy: Assures that individuals control or
influence what information related to them may be
collected and stored and by whom and to whom
that information may be disclosed
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Security Objectives (2 of 2)
Integrity: This term covers two related concepts:
Data integrity: Assures that data and programs are changed only
in a specified and authorized manner. This concept also
encompasses data authenticity, which means that a digital object
is indeed what it claims to be or what it is claimed to be, and
nonrepudiation, which is assurance that the sender of information
is provided with proof of delivery and the recipient is provided with
proof of the senders identity, so neither can later deny having
processed the information
System integrity: Assures that a system performs its intended
function in an unimpaired manner, free from deliberate or
inadvertent unauthorized manipulation of the system
Availability: Assures that systems work promptly and service is not
denied to authorized users
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Figure 1.1 Essential Information and
Network Security Objectives
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Computer Security Challenges
Security is not simple
Potential attacks on the security
features need to be considered
Procedures used to provide
particular services are often
counter-intuitive
It is necessary to decide where
to use the various security
mechanisms
Requires constant monitoring
Is too often an afterthought
Security mechanisms typically
involve more than a particular
algorithm or protocol
Security is essentially a battle of
wits between a perpetrator and
the designer
Little benefit from security
investment is perceived until a
security failure occurs
Strong security is often viewed as
an impediment to efficient and
user-friendly operation
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O S I Security Architecture
Security attack
Any action that compromises the security of information
owned by an organization
Security mechanism
A process (or a device incorporating such a process) that is
designed to detect, prevent, or recover from a security
attack
Security service
A processing or communication service that enhances the
security of the data processing systems and the information
transfers of an organization
Intended to counter security attacks, and they make use of
one or more security mechanisms to provide the service
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Threats and Attacks
Threat
A potential for violation of security, which exists when there
is a circumstance, capability, action, or event that could
breach security and cause harm. That is, a threat is a
possible danger that might exploit a vulnerability.
Attack
An assault on system security that derives from an intelligent
threat; that is, an intelligent act that is a deliberate attempt
(especially in the sense of a method or technique) to evade
security services and violate the security policy of a system.
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Figure 1.2 Key Concepts in Security (1 of 2)
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Figure 1.2 Key Concepts in Security
(2 of 2)
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Security Attacks
A means of classifying security attacks, used both in X.800
and R F C 4949, is in terms of passive attacks and active
attacks
A passive attack attempts to learn or make use of
information from the system but does not affect system
resources
An active attack attempts to alter system resources or
affect their operation
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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
Two types of passive
attacks are:
The release of message
contents
Traffic analysis
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Active Attacks
Involve some modification of the
data stream or the creation of a
false stream
Difficult to prevent because of the
wide variety of potential physical,
software, and network
vulnerabilities
Goal is to detect attacks and to
recover from any disruption or
delays caused by them
Masquerade
Takes place when one entity
pretends to be a different entity
Usually includes one of the other
forms of active attack
Replay
Involves the passive capture of a
data unit and its subsequent
retransmission to produce an
unauthorized effect
Data Modification
Some portion of a legitimate
message is altered, or messages
are delayed or reordered to
produce an unauthorized effect
Denial of service
Prevents or inhibits the normal use
or management of communications
facilities
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Figure 1.3 Security Attacks
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Authentication (1 of 2)
Concerned with assuring that a communication is authentic
In the case of a single message, assures the recipient
that the message is from the source that it claims to be
from
In the case of ongoing interaction, assures the two
entities are authentic and that the connection is not
interfered with in such a way that a third party can
masquerade as one of the two legitimate parties
Two specific authentication services are defined in X.800:
Peer entity authentication
Data origin authentication
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Authentication (2 of 2)
Peer entity authentication
Provides for the corroboration of the identity of a peer entity in an
association. Two entities are considered peers if they implement
the same protocol in different systems. Peer entity authentication
is provided for use at the establishment of, or at times during the
data transfer phase of, a connection. It attempts to provide
confidence that an entity is not performing either a masquerade or
an unauthorized replay of a previous connection
Data origin authentication
Provides for the corroboration of the source of a data unit. It does
not provide protection against the duplication or modification of
data units. This type of service supports applications like
electronic mail, where there are no ongoing interactions between
the communicating entities
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Access Control
The ability to limit and control the access to host systems
and applications via communications links
To achieve this, each entity trying to gain access must first
be identified, or authenticated, so that access rights can be
tailored to the individual
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Data Confidentiality
The protection of transmitted data from passive attacks
Broadest service protects all user data transmitted between
two users over a period of time
Narrower forms of service includes the protection of a single
message or even specific fields within a message
The protection of traffic flow from analysis
This requires that an attacker not be able to observe the
source and destination, frequency, length, or other
characteristics of the traffic on a communications facility
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Data Integrity
Can apply to a stream of messages, a single message, or
selected fields within a message
Connection-oriented integrity service, one that deals with a
stream of messages, assures that messages are received
as sent with no duplication, insertion, modification,
reordering, or replays
A connectionless integrity service, one that deals with
individual messages without regard to any larger context,
generally provides protection against message
modification only
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Nonrepudiation
Prevents either sender or receiver from denying a
transmitted message
When a message is sent, the receiver can prove that the
alleged sender in fact sent the message
When a message is received, the sender can prove that
the alleged receiver in fact received the message
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Availability Service
Protects a system to ensure its availability
This service addresses the security concerns raised by
denial-of-service attacks
It depends on proper management and control of system
resources and thus depends on access control service and
other security services
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Security Mechanisms (1 of 2)
Cryptographic algorithms: We can distinguish between
reversible cryptographic mechanisms and irreversible
cryptographic mechanisms. A reversible cryptographic
mechanism is simply an encryption algorithm that allows data to
be encrypted and subsequently decrypted. Irreversible
cryptographic mechanisms include hash algorithms and
message authentication codes, which are used in digital
signature and message authentication applications.
Data integrity: This category covers a variety of mechanisms
used to assure the integrity of a data unit or stream of data
units.
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.
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Security Mechanisms (2 of 2)
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 or
logically 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
Access control: A variety of mechanisms that enforce access
rights to resources.
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Figure 1.4 Cryptographic Algorithms
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Keyless Algorithms
Deterministic functions that have certain properties useful
for cryptography
One type of keyless algorithm is the cryptographic hash
function
A hash function turns a variable amount of text into a
small, fixed-length value called a hash value, hash
code, or digest
A cryptographic hash function is one that has additional
properties that make it useful as part of another
cryptographic algorithm, such as a message
authentication code or a digital signature
A pseudorandom number generator produces a
deterministic sequence of numbers or bits that has the
appearance of being a truly random sequence
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Single-Key Algorithms (1 of 3)
Single-key cryptographic algorithms depend on the use of
a secret key
Encryption algorithms that use a single key are referred to
as symmetric encryption algorithms
With symmetric encryption, an encryption algorithm
takes as input some data to be protected and a secret
key and produces an unintelligible transformation on
that data
A corresponding decryption algorithm takes the
transformed data and the same secret key and
recovers the original data
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Single-Key Algorithms (2 of 3)
Symmetric encryption takes the following forms:
Block cipher
A block cipher operates on data as a sequence of
blocks
In most versions of the block cipher, known as
modes of operation, the transformation depends not
only on the current data block and the secret key but
also on the content of preceding blocks
Stream cipher
A stream cipher operates on data as a sequence of
bits
As with the block cipher, the transformation depends
on a secret key
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Single-Key Algorithms (3 of 3)
Another form of single-key cryptographic algorithm is the
message authentication code (M A C)
A M A C is a data element associated with a data block
or message
The M A C is generated by a cryptographic
transformation involving a secret key and, typically, a
cryptographic hash function of the message
The M A C is designed so that someone in possession
of the secret key can verify the integrity of the message
The recipient of the message plus the M A C can
perform the same calculation on the message; if the
calculated M A C matches the M A C accompanying the
message, this provides assurance that the message
has not been altered
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Asymmetric Algorithms
Encryption algorithms that use a single key are referred to as
asymmetric encryption algorithms
Digital signature algorithm
A digital signature is a value computed with a cryptographic
algorithm and associated with a data object in such a way that any
recipient of the data can use the signature to verify the datas
origin and integrity
Key exchange
The process of securely distributing a symmetric key to two or
more parties
User authentication
The process of authenticating that a user attempting to access an
application or service is genuine and, similarly, that the application
or service is genuine
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Figure 1.5 Key Elements of Network
Security
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Communications Security
Deals with the protection of communications through the
network, including measures to protect against both passive and
active attacks
Communications security is primarily implemented using
network protocols
A network protocol consists of the format and procedures
that governs the transmitting and receiving of data between
points in a network
A protocol defines the structure of the individual data units
and the control commands that manage the data transfer
W ith respect to network security, a security protocol may be an
enhancement that is part of an existing protocol or a standalone
protocol
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Device Security (1 of 2)
The other aspect of network security is the protection of
network devices, such as routers and switches, and end
systems connected to the network, such as client systems
and servers
The primary security concerns are intruders that gain
access to the system to perform unauthorized actions,
insert malicious software (malware), or overwhelm system
resources to diminish availability
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Device Security (2 of 2)
Three types of device security are:
Firewall
A hardware and/or software capability that limits access
between a network and device attached to the network, in
accordance with a specific security policy. The firewall acts as
a filter that permits or denies data traffic, both incoming and
outgoing, based on a set of rules based on traffic content
and/or traffic pattern
Intrusion detection
Hardware or software products that gather and analyze
information from various areas within a computer or a network
for the purpose of finding, and providing real-time or near-real-
time warning of, attempts to access system resources in an
unauthorized manner
Intrusion prevention
Hardware or software products designed to detect intrusive
activity and attempt to stop the activity, ideally before it reaches
its target
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Trust Model (1 of 2)
One of the most widely accepted and most cited definitions
of trust is:
the willingness of a party to be vulnerable to the actions
of another party based on the expectation that the other
will perform a particular action important to the trustor,
irrespective of the ability to monitor or control that other
party
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Trust Model (2 of 2)
Three related concepts are relevant to a trust model:
Trustworthiness: A characteristic of an entity that
reflects the degree to which that entity is deserving of
trust
Propensity to trust: A tendency to be willing to trust
others across a broad spectrum of situations and trust
targets. This suggests that every individual has some
baseline level of trust that will influence the persons
willingness to rely on the words and actions of others
Risk: A measure of the extent to which an entity is
threatened by a potential circumstance or event, and
typically a function of 1) the adverse impacts that would
arise if the circumstance or event occurs; and 2) the
likelihood of occurrence
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Figure 1.6 Trust Model
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The Trust Model and Information
Security
Trust is confidence that an entity will perform in a way that will not
prejudice the security of the user of the system of which that entity is a
part
Trust is always restricted to specific functions or ways of behavior and
is meaningful only in the context of a security policy
Generally, an entity is said to trust a second entity when the first entity
assumes that the second entity will behave exactly as the first entity
expects
In this context, the term entity may refer to a single hardware
component or software module, a piece of equipment identified by
make and model, a site or location, or an organization
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Trustworthiness of an Individual
(1 of 2)
Organizations need to be concerned about both internal users
(employees, on-site contractors) and external users (customers,
suppliers) of their information systems
W ith respect to internal users, an organization develops a level of trust
in individuals by policies in the following two areas:
Human resource security
Sound security practice dictates that information security
requirements be embedded into each stage of the employment life
cycle, specifying security-related actions required during the
induction of each individual, their ongoing management, and
termination of their employment. Human resource security also
includes assigning ownership of information (including
responsibility for its protection) to capable individuals and
obtaining confirmation of their understanding and acceptance
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Trustworthiness of an Individual
(2 of 2)
Security awareness and training
This area refers to disseminating security information
to all employees, including I T staff, I T security staff,
and management, as well as I T users and other
employees. A workforce that has a high level of
security awareness and appropriate security training
for each individuals role is as important, if not more
important, than any other security countermeasure or
control
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Trustworthiness of an Organization
Most organizations rely on information system service and information
provided by external organizations, as well as partnerships to accomplish
missions and business functions (examples are cloud service providers and
companies that form part of the supply chain for the organization)
To manage risk to the organization, it must establish trust relationships with
these external organizations
N I S T S P 800-39 (Managing Information Security Risk, March 2011) indicates
that such trust relationships can be:
Formally established, for example, by documenting the trust-related
information in contracts, service-level agreements, statements of work,
memoranda of agreement/understanding, or interconnection security
agreements
Scalable and inter-organizational or intra-organizational in nature
Represented by simple (bilateral) relationships between two partners or
more complex many-to-many relationships among many diverse partners
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Trustworthiness of Information
Systems
S P 800-39 defines trustworthiness for information systems as
the degree to which information systems (including the information
technology products from which the systems are built) can be
expected to preserve the confidentiality, integrity, and availability of
the information being processed, stored, or transmitted by the
systems across the full range of threats
Two factors affecting the trustworthiness of information systems are:
Security functionality: The security features/functions employed
within the system. These include cryptographic and network
security technologies
Security assurance: The grounds for confidence that the security
functionality is effective in its application. This area is addressed
by security management techniques, such as auditing and
incorporating security considerations into the system development
life cycle
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Establishing Trust Relationships
Validated trust:
Trust is based on evidence obtained by the trusting organization about the
trusted organization or entity. The information may include information
security policy, security measures, and level of oversight
Direct historical trust:
This type of trust is based on the security-related track record exhibited by
an organization in the past, particularly in interactions with the
organization seeking to establish trust
Mediated trust:
Mediated trust involves the use of a third party that is mutually trusted by
two parties, with the third party providing assurance or guarantee of a
given level of trust between the first two parties
Mandated trust:
An organization establishes a level of trust with another organization
based on a specific mandate issued by a third party in a position of
authority
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Standards (1 of 2)
National Institute of Standards and Technology:
N I S T is a U.S. federal agency that deals with measurement science,
standards, and technology related to U.S. government use and to the
promotion of U.S. private-sector innovation. Despite its national scope, N I
S T Federal Information Processing Standards (F I P S) and Special
Publications (S P) have a worldwide impact
Internet Society:
I S O C is a professional membership society with worldwide organizational
and individual membership. It provides leadership in addressing issues
that confront the future of the Internet and is the organization home for the
groups responsible for Internet infrastructure standards, including the
Internet Engineering Task Force (I E T F) and the Internet Architecture
Board (I A B). These organizations develop Internet standards and related
specifications, all of which are published as Requests for Comments (R F
C s).
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Standards (2 of 2)
I T U-T:
The International Telecommunication Union (I T U) is an international
organization within the United Nations System in which governments and
the private sector coordinate global telecom networks and services. The I
T U Telecommunication Standardization Sector (I T U-T) is one of the three
sectors of the I T U. I T U-Ts mission is the development of technical
standards covering all fields of telecommunications. I T U-T standards are
referred to as Recommendations
I S O:
The International Organization for Standardization (I S O) is a worldwide
federation of national standards bodies from more than 140 countries,
one from each country. I S O is a nongovernmental organization that
promotes the development of standardization and related activities with a
view to facilitating the international exchange of goods and services and
to developing cooperation in the spheres of intellectual, scientific,
technological, and economic activity. I S Os work results in international
agreements that are published as International Standards
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Summary
Describe the key security requirements of confidentiality, integrity, and
availability
List and briefly describe key organizations involved in cryptography
standards
Provide an overview of keyless, single-key and two-key cryptographic
algorithms
Provide an overview of the main areas of network security
Describe a trust model for information security
Discuss the types of security threats and attacks that must be dealt
with and give examples of the types of threats and attacks that apply to
different categories of computer and network assets
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Copyright
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restrictions and to honor the intended pedagogical purposes and
the needs of other instructors who rely on these materials. After reading chapter 1, compare and contrast two fundamental security design principles. Analyze how these principles and how they impact an organizations security posture. The initial post must be completed by Thursday at 11:59 eastern. You must use at least one scholarly resource.
Every discussion posting must be properly APA formatted.
Plagiarism in the discussion will not be tolerated.
CHAPTER-1
Comments-1 100 words
Introduction
Security is the fundamental concern in operation or development of an information technology product. Usually there are three elements to be ensured in securing a product or service. These are Confidentiality, Integrity and Availability of data or services (Kibet & Karume, 2018). Some design principles are followed by the developers of IT tools to comply with these requirements.
Security Design
Personnel responsible for developing a product needs to ensure security for both hardware and software elements. Two very basic but crucial aspects of security that needs to be kept in mind are access control and authentication. Authentication is the assurance that the intended or permitted user is accessing the system. Thus, breach of security by third party access can be controlled with proper authentication mechanism. Access control is of two different kinds internal and external. External access control is closely related with authentication itself as it concerns with restricting access for external users of information system (Kibet & Karume, 2018). But, while authentication determines whether or no a user will be allowed to get access, access control determines to what extent a user can have access to the same. In internal organizational environment, Principle of Least Privilege (POLP) is often established to ensure access control for internal users. This principle can be applied in designing or developing IT products and services as well. Developers need to segment different tasks in the programme to enable POLP(Zheng, Xie, Dai, Chen & Wang, 2017). Least privilege not only helps in protecting information system from external attacks but also from human error that passes on to the connecting device or units. Today, most manufacturers and programmers are designing security with multi-factor authentication where security is more ensured by at least two different authentication factors such as a password and a biometric record.
Conclusion
However, standards and compliances are increasingly indicating the importance of security by design for IT products and performances. The aim behind this practice is reduce threat surface.
References
Kibet, A., & Karume, S. (2018). A Synopsis of Blockchain Technology.International Journal Of Advanced Research In Computer Engineering & Technology,7(11), 789-795.
Zheng, Z., Xie, S., Dai, H., Chen, X., & Wang, H. (2017). An Overview of Blockchain Technology: Architecture, Consensus, and Future Trends.2017 IEEE International Congress On Big Data (Bigdata Congress). doi: 10.1109/bigdatacongress.2017.85
Comments-2 100 words
Fundamental Design Principles
Complete mediation and open design are important fundamental security design principles that should be included in the consideration. Complete mediation involves a situation where each access should be checked against the access control mechanism that is applied. Platforms are not supposed to be relying on the access decisions that are retrieved from a particular cache. For a system that is designed for continuous operation, then this technique will have a special consideration (Alazzam et al., 2016). The access decisions need to be remembered for future use while changes in the authority need to be carefully considered depending on the alterations in the authoritative issuance of instructions to the designated directories.
The appearance of platforms for resource access usually gives instances of the platform required to provide compliance with the principle (Stallings, 2018). After file access and opening by end users, there would be no checking to see the changes in permission. The full implementation of me