Which of the following attacks are considered as authentication attacks?
Each correct answer represents a complete solution. Choose all that apply.

A.
Man-in-the-middle attack

B.
Eavesdropper attack

C.
Jamming attack

D.
Denial-of-Service (DoS) attack

Explanation:
Man-in-the-middle attacks occur when an attacker successfully inserts an intermediary software or program between two communicating hosts. The intermediary software or program allows attackers to listen to and modify the communication packets passing between the two hosts. The software intercepts the communication packets and thensends the information to the receiving host. The receiving host responds to the software, presuming it to be the legitimate client. Eavesdropping is the process of listening in private conversations. It also includes attackers listening in on the network traffic. For example, it can be done over telephone lines (wiretapping), e-mail, instant messaging, and any other method of communication considered private. Answer option C is incorrect. Jamming attacks can be a huge problem for wireless networks. Jamming is a technique that is used to simply shut down the wireless network. A jamming attack is performed whenever a hacker uses passive and active attacks to access valuable information from the network. Answer option D is incorrect. A Denial-of-Service (DoS) attack is mounted with the objective of causing a negative impact on the performance of a computer or network. It is also known as network saturation attack or bandwidth consumption attack. Attackers make Denial-of-Service attacks by sending a large number of protocol packets to a network.

A DoS attack can cause the following to occur:
Saturate network resources. Disrupt connections between two computers, thereby preventing communications between services. Disrupt services to a specific computer. A SYN attack is a common DoS technique in which an attacker sends multiple SYN packets to a target computer. For each SYN packet received, the target computer allocates resources and sends an acknowledgement (SYN-ACK) to the source IP address. Since the target computer does not receive a response from the attacking computer, it attempts to resend the SYN-ACK. This leaves TCP ports in the half-open state. When an attacker sends TCP SYNs repeatedly before the half-open connections are timed out, the target computer eventually runs out of resources and is unable to handle any more connections, thereby denying service to legitimate users. FactWhat is an attack? Hide An attack is an action against an information system or network that attempts to violate the system’s security policy. Attacks can be broadly classified as being either active or passive.
1. Active attacks modify the target system or message, i.e. they violate the integrity of the system or message.
2. Passive attacks violate confidentiality without affecting the state of the system. An example of such an attack is the electronic eavesdropping on network transmissions to release message contents or to gather unprotected passwords.