CISSP Exam Dumps : Certified Information Systems Security Professional (CISSP)

 Supplying a duress alarm for personnel exposed to the public is the most cost-effective method to provide a reactive control for protecting personnel in public areas. A duress alarm is a device that allows a person to signal for help in case of an emergency, such as an attack, a robbery, or a medical condition. A duress alarm can be activated by pressing a button, pulling a cord, or speaking a code word. A duress alarm can alert security personnel, law enforcement, or other responders to the location and nature of the emergency, and initiate appropriate actions. A duress alarm is a reactive control because it responds to an incident after it has occurred, rather than preventing it from happening.

The other options are not as cost-effective as supplying a duress alarm, as they involve more expensive or complex technologies or resources. Installing mantraps at the building entrances is a preventive control that restricts the access of unauthorized persons to the facility, but it also requires more space, maintenance, and supervision. Enclosing the personnel entry area with polycarbonate plastic is a preventive control that protects the personnel from physical attacks, but it also reduces the visibility and ventilation of the area. Hiring a guard to protect the public area is a deterrent control that discourages potential attackers, but it also involves paying wages, benefits, and training costs.

 Implementing logical network segmentation at the switches is the most effective layer of security the organization could have implemented to mitigate the attacker’s ability to gain further information. Logical network segmentation is the process of dividing a network into smaller subnetworks or segments based on criteria such as function, location, or security level. Logical network segmentation can be implemented at the switches, which are devices that operate at the data link layer of the OSI model and forward data packets based on the MAC addresses. Logical network segmentation can provide several benefits, such as:

• Isolating network traffic and reducing congestion and collisions
• Enhancing performance and efficiency of the network
• Improving security and confidentiality of the network
• Restricting the scope and impact of attacks
• Enforcing access control and security policies
• Facilitating monitoring and auditing of the network

Logical network segmentation can mitigate the attacker’s ability to gain further information by limiting the visibility and access of the sniffer to the segment where it is installed. A sniffer is a tool that captures and analyzes the data packets that are transmitted over a network. A sniffer can be used for legitimate purposes, such as troubleshooting, testing, or monitoring the network, or for malicious purposes, such as eavesdropping, stealing, or modifying the data. A sniffer can only capture the data packets that are within its broadcast domain, which is the set of devices that can communicate with each other without a router. By implementing logical network segmentation at the switches, the organization can create multiple broadcast domains and isolate the sensitive or critical data from the compromised segment. This way, the attacker can only see the data packets that belong to the same segment as the sniffer, and not the data packets that belong to other segments. This can prevent the attacker from gaining further information or accessing other resources on the network.

The other options are not the most effective layers of security the organization could have implemented to mitigate the attacker’s ability to gain further information, but rather layers that have other limitations or drawbacks. Implementing packet filtering on the network firewalls is not the most effective layer of security, because packet filtering only examines the network layer header of the data packets, such as the source and destination IP addresses, and does not inspect the payload or the content of the data. Packet filtering can also be bypassed by using techniques such as IP spoofing or fragmentation. Installing Host Based Intrusion Detection Systems (HIDS) is not the most effective layer of security, because HIDS only monitors and detects the activities and events on a single host, and does not prevent or respond to the attacks. HIDS can also be disabled or evaded by the attacker if the host is compromised. Requiring strong authentication for administrators is not the most effective layer of security, because authentication only verifies the identity of the users or processes, and does not protect the data in transit or at rest. Authentication can also be defeated by using techniques such as phishing, keylogging, or credential theft.

 Digital certificates are electronic documents that contain the public key of an entity and are signed by a trusted third party, called a Certificate Authority (CA). Digital certificates are used in Transport Layer Security (TLS), a protocol that provides secure communication over the Internet, by enabling the following functions:

• Server identity: The client can verify the identity of the server by checking the validity of its digital certificate and the signature of the CA.
• Data confidentiality: The client and the server can use the public keys in their digital certificates to establish a symmetric key for encrypting the data exchanged between them.
• Non-repudiation controls: The client and the server can use their private keys to digitally sign the data they send, which provides proof of origin and integrity of the data, and prevents the sender from denying the transmission.