From which of the following attacks can Message Authentication Code (MAC) shield your
network?

A.
DoS

B.
DDoS

C.
spoofing

D.
SYN floods

Explanation:
Message Authentication Code (MAC) can shield your network from spoofing attacks. Spoofing,
also known as masquerading, is a popular trick in which an attacker intercepts a network
packet, replaces the source address of the packets header with the address of the authorized
host, and reinserts fake information which is sent to the receiver. This type of attack involves
modifying packet contents. MAC can prevent this type of attack and ensure data integrity by
ensuring that no data has changed. MAC also protects against frequency analysis, sequence
manipulation, and ciphertext-only attacks.
MAC is a secure message digest that requires a secret key shared by the sender and receiver,
making it impossible for sniffers to change both the data and the MAC as the receiver can
detect the changes.
A denial-of-service (DoS) attack floods the target system with unwanted requests, causing the
loss of service to users. One form of this attack generates a flood of packets requesting a TCP
connection with the target, tying up all resources and making the target unable to service other
requests. MAC does not prevent DoS attacks. Stateful packet filtering is the most common
defense against a DoS attack.
A Distributed Denial of Service attack (DDoS) occurs when multiple systems are used to flood
the network and tax the resources of the target system. Various intrusion detection systems,
utilizing stateful packet filtering, can protect against DDoS attacks.
In a SYN flood attack, the attacker floods the target with spoofed IP packets and causes it to
either freeze or crash. A SYN flood attack is a type of denial of service attack that exploits the
buffers of a device that accept incoming connections and therefore cannot be prevented by
MAC. Common defenses against a SYN flood attack include filtering, reducing the SYNRECEIVED timer, and implementing SYN cache or SYN cookies.