Kerberos is a trusted, credential-based, third-party authentication protocol that uses symmetric (secret) key cryptography to provide robust authentication to clients accessing services on a network. Because a client’s password is used in the initiation of the Kerberos request for the service protocol, password guessing can be used to impersonate a client.
Here is a nice overview of HOW Kerberos is implement as described in RFC 4556:
1 Introduction
The Kerberos V5 protocol [RFC4120] involves use of a trusted third party known as the Key Distribution Center (KDC) to negotiate shared session keys between clients and services and provide mutual authentication between them.
The corner-stones of Kerberos V5 are the Ticket and the Authenticator. A Ticket encapsulates a symmetric key (the ticket session key) in an envelope (a public message) intended for a specific service. The contents of the Ticket are encrypted with a symmetric key shared between the service principal and the issuing KDC. The encrypted part of the Ticket contains the client principal name, among other items. An Authenticator is a record that can be shown to have been recently generated using the ticket session key in the associated Ticket. The ticket session key is known by the client who requested the ticket. The contents of the Authenticator are encrypted with the associated ticket session key. The encrypted part of an Authenticator contains a timestamp and the client principal name, among other items.
As shown in Figure 1, below, the Kerberos V5 protocol consists of the following message exchanges between the client and the KDC, and the client and the application service:
–
The Authentication Service (AS) Exchange
The client obtains an “initial” ticket from the Kerberos authentication server (AS), typically a Ticket Granting Ticket (TGT). The AS-REQ message and the AS-REP message are the request and the reply message, respectively, between the client and the AS.
–
The Ticket Granting Service (TGS) Exchange
The client subsequently uses the TGT to authenticate and request a service ticket for a particular service, from the Kerberos ticket-granting server (TGS). The TGS-REQ message and the TGS-REP message are the request and the reply message respectively between the client and the TGS.
–
The Client/Server Authentication Protocol (AP) Exchange
The client then makes a request with an AP-REQ message, consisting
of a service ticket and an authenticator that certifies the
client’s possession of the ticket session key. The server may
optionally reply with an AP-REP message. AP exchanges typically
negotiate session-specific symmetric keys.
Usually, the AS and TGS are integrated in a single device also known
as the KDC.
+————–+
+———>| KDC |
AS-REQ / +——-| |
/ / +————–+
/ / ^ |
/ |AS-REP / |
| | / TGS-REQ + TGS-REP
| | / /
| | / /
| | / +———+
| | / /
| | / /
| | / /
| v / v
++——-+——+ +—————–+
| Client +————>| Application |
| | AP-REQ | Server |
| |<————| |
+—————+ AP-REP +—————–+
Figure 1: The Message Exchanges in the Kerberos V5 Protocol
In the AS exchange, the KDC reply contains the ticket session key,
among other items, that is encrypted using a key (the AS reply key)
shared between the client and the KDC. The AS reply key is typically
derived from the client’s password for human users. Therefore, for
human users, the attack resistance strength of the Kerberos protocol
is no stronger than the strength of their passwords.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten
Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control systems
(page 40).
And
HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter
4: Access Control (pages 147-151). and http://www.ietf.org/rfc/rfc4556txt

ESP does have a source authentication and integrity capability through the use of a hash algorithm and a secret key. It provides confidentiality by means of secret key cryptography.
DES and triple DES secret key block ciphers are supported by IPSEC and other algorithms will also be supported in the future. AH uses a hash algorithm in the packet header to authenticate the sender and validate the integrity of the transmitted data.

Residual risk is “The security risk that remains after controls have been implemented” ISO/IEC TR 13335-1 Guidelines for the Management of IT Security (GMITS),
Part 1: Concepts and Models for IT Security, 1996. “Weakness of an assets which can be exploited by a threat” is vulnerability. “The result of unwanted incident” is impact. Risk that remains after risk analysis has been performed is a distracter.
Risk can never be eliminated nor avoided, but it can be mitigated, transferred or accpeted.
Even after applying a countermeasure like for example putiing up an Antivirus. But still it is not 100% that systems will be protected by antivirus.

A software assurance policy defines the organization’s approach to evaluating, verifying, and validating the security of software during acquisition, development, and deployment.
It ensures that:
* Security requirements are assessed during procurement
* Software meets trustworthiness and integrity standards
* Risk from third-party or COTS (Commercial Off-the-Shelf) software is minimized

Authentication is effected in GSM through the use of a common secret key, Ks, that is stored in the network operator’s Authentication Center (AuC) and in the subscriber’s SIM card. The SIM card may be in the subscriber’s laptop, and the subscriber is not privy to Ks. To begin the authentication exchange, the home location of the subscriber’s mobile station, (MS), generates a 128-bit random number (RAND) and sends it to the MS. Using an algorithm that is known to both the AuC and MS, the RAND is encrypted by both parties using the secret key, Ks. The ciphertext generated at the MS is then sent to the AuC and compared with the ciphertext generated by the Auc. If the two results match, the MS is authenticated and the access request is granted. If they do not match, the access request is denied. The other answers are, therefore, incorrect.

Explanation/Reference:
Explanation:
Alarms are an example of a physical control type, not an administrative control.
Controls are put into place to reduce the risk an organization faces, and they come in three main flavors:
administrative, technical, and physical. Administrative controls are commonly referred to as “soft controls” because they are more management-oriented. Examples of administrative controls are security documentation, risk management, personnel security, and training. Technical controls (also called logical controls) are software or hardware components, as in firewalls, IDS, encryption, identification and authentication mechanisms. And physical controls are items put into place to protect facility, personnel, and resources. Examples of physical controls are security guards, locks, fencing, and lighting.
Incorrect Answers:
A: Personnel controls are an example of an administrative control. Therefore, this answer is incorrect.
C: Training is an example of an administrative control. Therefore, this answer is incorrect.
D: Emergency response and procedures are an example of an administrative control. Therefore, this answer is incorrect.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, p. 28

The best technique to address the threat of an imminent DDoS attack targeting a web application is to coordinate with and utilize the capabilities within the ISP. A DDoS attack is a malicious attempt to disrupt the normal traffic of a targeted server, service, or network by overwhelming the target or its surrounding infrastructure with a flood of Internet traffic. A DDoS attack can cause severe damage to the availability, performance, and reputation of the web application, as well as incur financial losses and legal liabilities.
Therefore, it is important to have a DDoS mitigation strategy in place to prevent or minimize the impact of such attacks. One of the most effective ways to mitigate DDoS attacks is to leverage the capabilities of the ISP, as they have more resources, bandwidth, and expertise to handle large volumes of traffic and filter out malicious packets. The ISP can also provide additional services such as traffic monitoring, alerting, reporting, and analysis, as well as assist with the investigation and prosecution of the attackers. The ISP can also work with other ISPs and network operators to coordinate the response and share information about the attack. The other options are not the best techniques to address the threat of an imminent DDoS attack, as they may not be sufficient, timely, or scalable to handle the attack. Deploying load balancers, setting up web application firewalls, and implementing reverse web-proxies are some of the measures that can be taken at the application level to improve the resilience and security of the web application, but they may not be able to cope with the magnitude and complexity of a DDoS attack, especially if the attack targets the network layer or the infrastructure layer. Moreover, these measures may require more time, cost, and effort to implement and maintain, and may not be feasible to deploy in a short notice. References: What is a distributed denial-of-service (DDoS) attack?; What is a DDoS Attack? DDoS Meaning, Definition & Types | Fortinet; Denial-of-service attack – Wikipedia.

Brute force attacks are performed with tools that cycle through many possible character, number, and symbol combinations to guess a password. Pg 134 Shon Harris CISSP All-In-One Certification Exam Guide. Since the token allows offline checking of PIN, the cracker can keep trying PINS until it is cracked.

The best way to mitigate a replay attack against a system using identity federation and Security Assertion Markup Language (SAML) implementation is to use timed sessions and Secure Socket Layer (SSL). A replay attack is a type of network attack that involves capturing and retransmitting a valid message or data to gain unauthorized access or perform malicious actions. Identity federation is a process that enables the sharing of identity information across different security domains, such as different organizations or applications. SAML is a standard protocol that enables identity federation by using XML-based assertions to exchange authentication and authorization information. To prevent a replay attack, the system can use timed sessions and SSL. Timed sessions are sessions that have a limited duration and expire after a certain period of time or inactivity. SSL is a protocol that provides encryption and authentication for data transmission over the internet. By using timed sessions and SSL, the system can ensure that the SAML assertions are valid, fresh, and secure, and that they cannot be reused or tampered with by an attacker. Two-factor authentication, digital certificates and hardware tokens, and passwords with alpha-numeric and special characters are not the best ways to mitigate a replay attack against a system using identity federation and SAML implementation, as they do not address the specific vulnerabilities of the SAML protocol or the network transmission.

The most secure password technique is the one-time password. A one-time password is a password that is valid for only one login session or transaction, and that is randomly generated or derived from a secret key or algorithm. A one-time password can help to enhance the security of the authentication process, by preventing the password from being reused, guessed, stolen, or intercepted by unauthorized parties. A one-time password can also help to protect against various password-based attacks, such as replay, brute force, or phishing attacks. A one-time password can be implemented by using various methods or techniques, such as hardware tokens, software tokens, SMS messages, or biometric factors. Passphrase, cognitive password, or ciphertext are not the most secure password techniques, as they are either less complex, less random, or less dynamic than the one-time password.

Explanation/Reference:
Explanation:
Various operating system software products provide parameters and options for the tailoring of the system and activation of features such as activity logging. Parameters are important in determining how a system runs because they allow a standard piece of software to be customized to diverse environments. The reviewing of software control features and/or parameters is the most effective means of determining how controls are functioning within an operating system and of assessing and operating system’s integrity.
The review of software control features and/or parameters would be part of your security audit. A security audit is typically performed by an independent third party to the management of the system. The audit determines the degree with which the required controls are implemented.
A security review is conducted by the system maintenance or security personnel to discover vulnerabilities within the system. A vulnerability occurs when policies are not followed, misconfigurations are present, or flaws exist in the hardware or software of the system. System reviews are sometimes referred to as a vulnerability assessment.
Incorrect Answers:
A: An interview with the computer operator is not an effective means of determining that controls are functioning properly within an operating system because the computer operator will not necessarily be aware of the detailed settings of the parameters.
C: The operating system manual should provide information as to what settings can be used but will not give any hint as to how parameters are actually set.
D: An interview with the product vendor is not an effective means of determining that controls are functioning properly within an operating system because the product vendor will not be aware of the detailed settings of the parameters.