Free Preparation Discussions
MENU
EC-Council Network Defense Essentials NDE 112-51 Exam Questions
- Topic 1: Network Security Fundamentals: This component assesses an IT professional's knowledge of the principles behind network security, as well as the dangers and weaknesses connected to networks. This section aims to provide network engineers and security experts with an understanding of the various network security protocols, their purposes, and the ways in which they contribute to the overall security of the network.
- Topic 2: Identification, Authentication, and Authorization: This part addresses the basic concepts, jargon, and models associated with identifying, authenticating, and authorizing users and systems in a network environment. It is intended for security administrators and access control managers.
- Topic 3: Identity and Access Management (IAM) Concepts: An overview of IAM concepts, components, and their function in network resource security is given in this section for security architects and IAM administrators.
- Topic 4: Administrative Controls for Network Security: This section gives an overview of IAM ideas, components, and its function in network resource security for security architects and IAM administrators.
- Topic 5: Administrative Controls for Network Security: This section addresses the creation and application of security policies, standards, processes, and recommendations for compliance officers and security policy makers to safeguard network assets. It also entails being aware of the legal and regulatory frameworks around network security.
- Topic 6: Physical Controls for Network Security: This section highlights the significance of physical security measures for safeguarding network infrastructure and data, especially for physical security workers and building managers. It addresses several physical security measures and how to apply them.
- Topic 7: Technical Controls for Network Security: This section is intended for network engineers and security architects and focuses on technical safeguards for network systems and data.
Free EC-Council Network Defense Essentials NDE 112-51 Exam Actual Questions
Note: Premium EC-Council Network Defense Essentials Exam NDE 112-51 Practice Questions — Last Updated: Oct. 16, 2026 (see below)
Which of the following algorithms uses a sponge construction where message blocks are XORed into the initial bits of the state that the algorithm then invertible permutes?
SHA-3 is the algorithm that uses a sponge construction where message blocks are XORed into the initial bits of the state that the algorithm then invertible permutes. SHA-3 is a family of cryptographic hash functions that was standardized by NIST in 2015 as a successor to SHA-2. SHA-3 is based on the Keccak algorithm, which won the NIST hash function competition in 2012. SHA-3 uses a sponge construction, which is a simple iterated construction that can produce variable-length output from a fixed-length permutation. The sponge construction operates on a state of b bits, which is divided into two sections: the bitrate r and the capacity c. The sponge construction has two phases: the absorbing phase and the squeezing phase. In the absorbing phase, the input message is padded and divided into blocks of r bits. Each block is XORed into the first r bits of the state, and then the state is transformed by the permutation function f. This process continues until all the input blocks are processed. In the squeezing phase, the output is generated by repeatedly applying the permutation function f to the state and extracting the first r bits as output blocks. The output can be truncated to the desired length. SHA-3 uses a permutation function f that is based on a round function that consists of five steps: theta, rho, pi, chi, and iota. These steps perform bitwise operations, rotations, permutations, and additions on the state. The permutation function f is invertible, meaning that it can be reversed to obtain the previous state. SHA-3 has four variants with different output lengths: SHA3-224, SHA3-256, SHA3-384, and SHA3-512. SHA-3 also supports two additional modes: SHAKE128 and SHAKE256, which are extendable-output functions that can produce arbitrary-length output. Reference:
Network Defense Essentials Courseware, EC-Council, 2020, pp. 3-23 to 3-25
SHA-3 - Wikipedia, Wikipedia, March 16, 2021
The sponge and duplex constructions - Keccak Team, Keccak Team, 2020
Jamie wants to send a confidential file to her friend Alice. For this purpose, they installed an application for securely sharing the file. The application employs an encryption algorithm that uses the same shared secret key for encryption and decryption of data.
Identify the type of cryptography employed by the application used by Alice and Jamie for file sharing.
Amber is working as a team lead in an organization. She was instructed to share a policy document with all the employees working from remote locations and collect them after filling. She shared the files from her mobile device to the concerned employees through the public Internet. An unauthorized user accessed the file in transit, modified the file, and forwarded it to the remote employees.
Based on the above scenario, identify the security risk associated with mobile usage policies.
Sharing confidential data on an unsecured network is a security risk associated with mobile usage policies. Mobile devices are often used to access and transmit sensitive information over public or untrusted networks, such as WiFi hotspots, cellular networks, or Bluetooth connections. This exposes the data to interception, modification, or redirection by malicious actors who may exploit mobile security vulnerabilities or use network-based attacks, such as man-in-the-middle, spoofing, or sniffing. To prevent this risk, mobile users should follow best practices such as using encryption, VPN, certificate pinning, and secure protocols to protect the data in transit. They should also avoid sending or receiving sensitive data over unsecured networks or applications, and verify the identity and integrity of the endpoint servers before establishing a connection. Reference:
The 9 Most Common Security Threats to Mobile Devices in 2021, Auth0, June 25, 2021
7 Mobile App Security Risks and How to Mitigate Them, Cypress Data Defense, July 10, 2020
The Latest Mobile Security Threats and How to Prevent Them, Security Intelligence, February 19, 2019
George, a certified security professional, was hired by an organization to ensure that the server accurately responds to customer requests. In this process, George employed a security solution to monitor the network traffic toward the server. While monitoring the traffic, he identified attack signatures such as SYN flood and ping of death attempts on the server.
Which of the following categories of suspicious traffic signature has George identified in the above scenario?
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
Kevin, a security team member, was instructed to share a policy document with the employees. As it was supposed to be shared within the network, he used a simple algorithm to encrypt the document that just rearranges the same characters to produce the ciphertext.
Identify the type of cipher employed by Kevin in the above scenario.
A transposition cipher is a type of cipher that encrypts a document by rearranging the same characters to produce the ciphertext. A transposition cipher does not change the identity or frequency of the characters, but only their position. A transposition cipher can use various methods to permute the characters, such as writing them in a grid and reading them in a different order, or shifting them along a rail fence pattern. A transposition cipher is a simple and fast algorithm, but it can be easily broken by frequency analysis or anagramming. A transposition cipher is the type of cipher employed by Kevin in the above scenario, as he used a simple algorithm to encrypt the document that just rearranges the same characters to produce the ciphertext. Reference:
Transposition cipher - Wikipedia
Network Security: Transposition Cipher Techniques - Coding Streets
Network Defense Essentials (NDE) | Coursera - Module 4: Cryptography Techniques
Columnar Transposition Cipher - GeeksforGeeks
- Select Question Types you want
- Set your Desired Pass Percentage
- Allocate Time (Hours : Minutes)
- Create Multiple Practice tests with Limited Questions
- Customer Support
Gary Bailey
24 days agoRyan Adams
1 month agoPatricia Phillips
2 months agoHarold Nguyen
2 months agoGeorge Torres
3 months agoTimothy Flores
3 months agoGerald Mitchell
4 months agoRachel Peterson
4 months agoPatricia Murphy
5 months agoDennis Bailey
5 months agoJoshua Taylor
6 months agoLaura Roberts
6 months agoMargaret Walker
6 months agoLisa Campbell
6 months agoCarol Flores
5 months agoKaren Perez
5 months agoNatalie
7 months agoZena
7 months agoJettie
7 months agoTresa
7 months agoLillian
8 months agoKristel
8 months agoRessie
8 months agoDenny
8 months agoSusana
9 months agoSage
9 months agoCortney
9 months agoTu
9 months agoTenesha
10 months agoCarin
10 months agoTheodora
10 months agoCarla
10 months agoLillian
11 months agoRessie
11 months agoLelia
11 months agoDavida
11 months agoMarica
12 months agoGeorgiann
12 months agoSharmaine
1 year agoBrandon
1 year agoRicarda
1 year agoVilma
1 year agoLeatha
1 year agoElmira
1 year agoGerald
1 year agoTheodora
1 year agoHerman
1 year agoLashawna
1 year agoMicaela
1 year agoAudry
1 year agoFausto
1 year agoErinn
1 year agoIluminada
2 years agoLashawn
2 years agoCandra
2 years agoAimee
2 years agoVicky
2 years agoKristofer
2 years agoDong
2 years agoBobbie
2 years agoEvette
2 years agoSalena
2 years agoLai
2 years agoDestiny
2 years agoVallie
2 years agoCarylon
2 years agoGenevive
2 years agoLoreen
2 years agoJenifer
2 years agoEun
2 years agoAudry
2 years agoLorrine
2 years agoAudria
2 years agoJeanice
2 years agoJuan
2 years agoJill
2 years agoMicheline
2 years agoAnnamaria
2 years agoTiara
2 years agoRefugia
2 years agoJolanda
2 years agoEugene
2 years agoErnest
2 years agoLouisa
2 years agoDelsie
2 years agoJuliann
2 years agoGennie
2 years agoDonte
2 years agoDorcas
2 years agoXenia
2 years agoJody
2 years agoShizue
2 years agoWeldon
3 years ago