:

The correct sequence of steps involved in establishing a network connection using the shared key

authentication process is 4 -> 1 -> 3 -> 5 -> 2. This is based on the following description of the shared

key authentication process from the Network Defense Essentials courseware:

The station sends an authentication frame to the AP, indicating that it wants to use shared key

authentication.

The AP responds with an authentication frame containing a challenge text, which is a random string

of bits.

The station encrypts the challenge text using its configured WEP key, which is derived from the

shared secret key (password) that is also known by the AP. The station sends the encrypted text back

to the AP in another authentication frame.

The AP decrypts the encrypted text using its configured WEP key and compares it with the original

challenge text. If they match, the AP sends a positive authentication response to the station. If they

do not match, the AP sends a negative authentication response to the station.

The station connects to the network if the authentication is successful.

Reference:

Network Defense Essentials Courseware, EC-Council, 2020, pp. 3-18 to 3-19

Shared Key Authentication - Techopedia, Techopedia, June 15, 2017

Denial-of-service (DoS) is the category of suspicious traffic signature that George identified in the

above scenario. DoS signatures are designed to detect attempts to disrupt or degrade the availability

or performance of a system or network by overwhelming it with excessive or malformed traffic. SYN

flood and ping of death are examples of DoS attacks that exploit the TCP/IP protocol to consume the

resources or crash the target server. A SYN flood attack sends a large number of TCP SYN packets to

the target server, without completing the three-way handshake, thus creating a backlog of half-open

connections that exhaust the server’s memory or bandwidth. A ping of death attack sends a

malformed ICMP echo request packet that exceeds the maximum size allowed by the IP protocol,

thus causing the target server to crash or reboot. DoS attacks can cause serious damage to the

organization’s reputation, productivity, and revenue, and should be detected and mitigated as soon

as possible123. Reference:

Network Defense Essentials Courseware, EC-Council, 2020, pp. 3-33 to 3-34

What is a denial-of-service attack?, Cloudflare, 2020

Denial-of-service attack - Wikipedia, Wikipedia, March 16, 2021

The communication layer of IoT architecture employs protocols and networks for connecting,

sending, and receiving data between devices and network. The communication layer is responsible

for enabling data exchange among the IoT devices and the cloud or other devices. The

communication layer can use various types of networks, such as wired, wireless, cellular, or satellite,

and various types of protocols, such as TCP/IP, MQTT, CoAP, or ZigBee12. Reference: Network

Defense Essentials - EC-Council Learning, IoT Architecture: The 4 Layers of an IoT System

Two-factor authentication (2FA) is a type of authentication that requires users to provide two or

more forms of verification to access an online account. 2FA is a multi-layered security measure

designed to prevent hackers from accessing user accounts using stolen or shared credentials. 2FA

typically combines something the user knows (such as a password or PIN), something the user has

(such as a phone or a token), and/or something the user is (such as a fingerprint or a face scan). In

the above scenario, the banking application employs 2FA by asking Kevin to enter his registered

credentials (something he knows) and an OTP sent to his mobile (something he has) before

transferring the amount to Flora’s account. Reference:

Improve Your Cybersecurity with Password MFA - Defense.com™

What Is Two-Factor Authentication (2FA)? | Microsoft Security

Selecting Secure Multi-factor Authentication Solutions