1.Write a short note on Email Security.

● S/MIME or Secure/Multipurpose Internet Mail Extension is a technology widely used by corporations that
enhances email security by providing encryption, which protects the content of email messages from
unwanted access.
● It also adds digital signatures, which confirm that you are the authentic sender of the message, making it a
powerful weapon against many email-based attacks.
● S/MIME is a commonly-used protocol for sending encrypted and digitally-signed email messages and is
implemented using S/MIME certificates.

2. List S/MIME services.

Email Encryption ,Data Confidentiality, Digital Signature. , Signature Authentication. ,Non-repudiation by the
Sender. ,Content Integrity of the Email. ,Phishing and Spoofing. ,Email tampering.

3) Compare HTTP and HTTPS

HTTP HTTPS

HTTPS stands for HyperText Transfer Protocol

HTTP stands for HyperText Transfer Protocol.
Secure.

URL begins with “http://”. U URL starts with “https://”.

HTTP Works at the Application Layer. HTTPS works at Transport Layer.

HTTP speed is faster than HTTPS. HTTPS speed is slower than HTTP.

HTTP is used to transfer text ,video, and images HTTPS is used to transfer data
via web pages. securely via a network.

HTTP uses port number 80 for HTTPS uses port number 443 for
communication. communication.

4 Types of Network Access Control:

1 Pre-admission: It happens before access to the network is granted on initialization of request by user or
device to access the network. It evaluates the access attempt and only allows the access if the user or device is
compliant with organization security policies and authorized to access the network.
2 Post-admission: It happens within the network when the user or device attempts to access the different
parts of the network. It restricts the lateral movement of the device within the network by asking for re-
authentication for each request to access a different part of the network.

5) Enlist and explain use cases for Network Access Control

1 Organizations that allow employees to use their own devices or take corporate devices home use NAC to
ensure network security.
2 Organizations use NAC to grant access to different network resources to people or devices that are outside
of the organization and are subjected to different security controls.
3 NAC protects from threats caused due to use of IoT devices by categorizing IoT devices into groups that
have limited permission and constantly monitoring their activities.
Q2 B Explain principle Elements of NAC.
There are mainly three principle elements of NAC which are:
1.Access Requestor(AR).
2.Policy Servers.
3.Network Access Servers(NAS).

Three Principle Elements of NAC(Network Access Control).

Let’s look at them one by one now:
1) .Access Requestor(AR): 1) We may determine from the name that it is someone attempting to gain access
by requesting it. This access can be granted to any entity, such as a device, person, or process.
2) This entity attempts to get access to network resources. It might be any device handled by the NAC system,
such as servers, cameras, printers, and other IP-enabled devices.
3) ARs are also known as supplicants or clients at times. ARs ensures that no entity has illegal access to
protected resources.
To get access, these ARs must follow to the organization’s specific guidelines or policies.
2) .Policy Server: 1 )The policy server analyzes what access should be provided to AR based on the AR’s
identity, permission level, attempted request, and an organization’s established access policy.
2) The policy server frequently relies on backend services, such as antivirus, patch management, or a user
directory, to function.
3)The policy server helps to determine the host’s state. An organization creates different access policies to
clearly authorize or reject such access. If the AR follows the organization’s policy, the policy server gives
access based on the requestor’s permission; otherwise, the AR will not be permitted access based on its
permission.
4)It should be noted that there are various commercial systems on the market now that provide such policy
servers for both on-premises and cloud computing. Some of the most common examples include the Cisco
Identity Services Engine(ISE), Forescout Platform, Aruba ClearPass Policy Manager, and FortiNAC.
5) These tools offer highly detailed ways to set organizational rules and control the organization’s full IP
infrastructure.
3). Network Access Server(NAS): 1) Users connecting to an organization’s internal network from distant
locations utilize the NAS as an access control point. These often serve as VPNs and give users access to the
company’s internal network. These days, NAS functionality is frequently included in policy server systems.
2) Remote employees can connect to the company’s internal network via NAS, which serves as an access
point for them. This allows the company and its employees to create a secure connection and grant
authorized access to the network.
Thus, these were the Three Principle Elements of NAC (Network Access control).
Q3 1 ) What is VPN? Describe types of VPN and VPN Protocols.
A Virtual Private Network (VPN) is a service that creates a virtual network on top of physical data
flows. Data packets move through encrypted tunnels that wrap payloads in unbreakable code.
Servers also anonymize user identities, assigning new IP addresses to each packet. This allows users
to change their digital location and evade surveillance or cyber criminals. TLS VPNs are usually
clientless. There is no need for separate software to establish connections and control access. This
style of VPN also works with HTTP, allowing it to work seamlessly with most modern websites. It
functions in the background, addinganother cybersecurity barrier for web users.
1. Remote Access VPN : Remote Access VPN permits a user to connect to a private network and
access all its services and resources remotely. The connection between the user and the private
network occurs through the Internet and the connection is secure and private. Remote Access VPN
is useful for home users and business users both.
2. Site to Site VPN :A Site-to-Site VPN is also called as Router-to-Router VPN and is commonly used in
the large companies. Companies or organizations, with branch offices in different locations, use
Site-to-site VPN to connect the network of one office location to the network at another office
location.
● Intranet based VPN: When several offices of the same company are connected using Site-to-Site
VPN type, it is called as Intranet based VPN.
● Extranet based VPN: When companies use Site-to-site VPN type to connect to the office of another
company, it is called as Extranet based VPN.
3. Cloud VPN : A Cloud VPN is a virtual private network that allows users to securely connect to a
cloud-based infrastructure or service. It uses the internet as the primary transport medium to
connect the remote users to the cloud-based resources. Cloud VPNs are typically offered as a
service by cloud providers such as Amazon Web Services (AWS) and Microsoft Azure. It uses the
same encryption and security protocols as traditional VPNs, such as IPsec or SSL, to ensure that the
data transmitted over the VPN is secure. Cloud VPNs are often used by organizations to securely
connect their on-premises resources to cloud-based resources, such as cloud-based storage or
software-as-a-service (SaaS) applications.
4. Mobile VPN : Mobile VPN is a virtual private network that allows mobile users to connect to a
private network, typically through a cellular network. It creates a secure and encrypted connection
between the mobile device and the VPN server, protecting the data transmitted over the
connection. Mobile VPNs can be used to access corporate resources, such as email or internal
websites, while the user is away from the office. They can also be used to securely access public
Wi-Fi networks, protecting the user’s personal information from being intercepted.

Types of Virtual Private Network (VPN) Protocols:

1. Internet Protocol Security (IPSec):
2. Layer 2 Tunneling Protocol (L2TP):.
3. Point–to–Point Tunneling Protocol (PPTP):
4. SSL and TLS:
5. Secure Shell (SSH):
6. SSTP (Secure Socket Tunneling Protocol):
7. IKEv2 (Internet Key Exchange version 2):
8. OpenVPN:
9. WireGuard
Q3 How does IPSec help to achieve authentication and confidentiality? Justify the need of AH and ESP.