ISC CISSP Certified Information Systems Security Professional Exam Dumps and Practice Test Questions Set 10 Q136-150
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Question 136:
Which type of cloud service provides users with a platform to develop, run, and manage applications without managing underlying infrastructure?
A) Infrastructure as a Service
B) Platform as a Service
C) Software as a Service
D) Function as a Service
Answer: B
Explanation:
Infrastructure as a Service (IaaS) provides virtualized computing resources such as virtual machines, storage, and networking. Users are responsible for managing operating systems, applications, and middleware. While IaaS provides flexibility and control, it still requires organizations to handle configuration, patching, and security management for the operating systems and applications running on the infrastructure. This model is ideal for teams needing full control over their environments while avoiding physical hardware concerns.
Software as a Service (SaaS) delivers fully managed applications to users over the internet, eliminating the need for local installation and management. Examples include email services, office productivity suites, and CRM systems. SaaS simplifies usage because providers handle the infrastructure, middleware, and updates. However, customization is limited, and organizations typically cannot modify the underlying application or environment.
Function as a Service (FaaS) is a serverless model in which developers deploy individual functions or small units of code triggered by events. The cloud provider manages all infrastructure, scaling, and runtime requirements. FaaS is highly scalable and cost-effective for event-driven workloads, but it is not designed for full application development and lifecycle management.
Platform as a Service (PaaS) provides an integrated environment for developing, testing, and deploying applications without managing the underlying infrastructure, including servers, storage, or networking. Developers focus on building functionality and user experiences while the cloud provider handles OS updates, runtime, middleware, and scalability. PaaS often includes development frameworks, database management, and automated deployment tools. By removing operational burdens, PaaS accelerates development timelines, enhances collaboration, and supports continuous integration and continuous deployment (CI/CD) pipelines. PaaS is widely used for web applications, mobile backends, and enterprise software solutions where agility, rapid deployment, and abstraction from infrastructure complexity are essential.
The platform allows teams to scale applications seamlessly, maintain secure environments, and adhere to compliance requirements without manually configuring servers or managing runtime dependencies. PaaS providers often integrate analytics, monitoring, and logging tools, enabling developers to maintain high-quality, performant applications while focusing on innovation. This model is particularly beneficial in environments with rapid development cycles or when applications require cross-platform compatibility.
The cloud service providing a complete environment for building, deploying, and managing applications without infrastructure management is Platform as a Service, making it the correct answer.
Question 137:
Which type of cryptographic attack compares captured hashes to a precomputed list of hash-value pairs?
A) Brute-force attack
B) Rainbow table attack
C) Man-in-the-middle attack
D) Replay attack
Answer: B
Explanation:
A brute-force attack involves systematically trying every possible combination of characters or keys to discover a password, encryption key, or cryptographic hash. This approach guarantees success if sufficient time and resources are available, but it is extremely resource-intensive. Brute-force attacks are often mitigated using complex passwords, rate limiting, or computationally expensive hashing functions like bcrypt or Argon2.
Man-in-the-middle (MitM) attacks intercept communication between two parties to eavesdrop, capture sensitive data, or inject malicious content. These attacks exploit network vulnerabilities but do not directly target hash values or precomputed hash tables. MitM attacks can be mitigated through encryption protocols such as TLS, strong authentication, and certificate validation.
Replay attacks capture valid network messages or authentication data and retransmit them to gain unauthorized access. Although effective in poorly designed authentication systems, replay attacks focus on exploiting the transmission of data rather than precomputed hashes. Countermeasures include using timestamps, nonces, or cryptographic tokens to ensure each message is unique and time-bound.
Rainbow table attacks are a cryptographic technique in which attackers use precomputed tables containing hash values and corresponding plaintext pairs. When an attacker obtains a hashed password, they compare it against the rainbow table to quickly identify the original input. This significantly reduces the time required compared to brute-force attacks. The effectiveness of rainbow tables depends on the absence of salting in password hashing; salted hashes require unique precomputed tables for each salt, making the attack impractical. Rainbow table attacks highlight the importance of secure hashing mechanisms, salting, and iterative hashing to enhance password security.
These attacks exploit the predictable nature of unsalted hash functions and are widely discussed in cybersecurity best practices and penetration testing scenarios. Security professionals recommend hashing algorithms resistant to precomputation attacks, such as bcrypt, scrypt, and Argon2, which incorporate salting and multiple iterations. Understanding rainbow table attacks helps organizations enforce stronger password policies, protect user data, and strengthen cryptographic implementations against offline attacks.
The cryptographic attack that relies on precomputed hash-value tables to reverse hashes efficiently is the Rainbow table attack, making it the correct answer.
Question 138:
Which security principle ensures a system continues to operate securely even if its internal design becomes public knowledge?
A) Security through obscurity
B) Open design
C) Least functionality
D) Defense in depth
Answer: B
Explanation:
Security through obscurity depends on keeping system design or implementation details secret. While secrecy may offer temporary protection, it is not reliable because once design details are exposed, the system becomes vulnerable. This approach is often criticized for creating a false sense of security and discouraging thorough analysis and testing.
The least functionality reduces the attack surface by limiting services, features, or applications running on a system. While it minimizes potential vulnerabilities, it does not inherently ensure security if design details are publicly known. This principle is often implemented alongside other security measures rather than standing alone.
Defense in depth layers multiple security controls such as firewalls, intrusion detection systems, authentication mechanisms, and encryption. It improves overall resilience but does not inherently depend on whether the system design is public or private.
Open design is a principle asserting that security should rely on strong, well-engineered systems rather than secrecy. The effectiveness of controls should be independent of whether internal mechanisms are known to attackers. Open design encourages transparency, allowing thorough peer review, auditing, and rigorous testing, which leads to stronger and more reliable systems. It also facilitates compliance with industry standards, security certifications, and regulatory requirements.
Implementing open design ensures that even if adversaries understand the system architecture, security controls such as encryption, authentication, access controls, and auditing remain effective. This principle also supports the development of modular and maintainable systems, as security considerations are embedded into design and architecture rather than patched after deployment. It emphasizes secure coding practices, proper error handling, and well-defined protocols.
Open design allows organizations to gain confidence in system resilience, supports reproducible security testing, and promotes trust in software and hardware solutions. It is widely adopted in cryptographic systems, security protocols, and critical infrastructure. By focusing on robust architecture rather than secrecy, open design reduces reliance on unknown factors and fosters long-term security reliability.
The security principle that ensures protection even if internal workings are public is Open design, making it the correct answer.
Question 139:
Which backup method copies all files changed since the last full backup without resetting the archive bit?
A) Full backup
B) Differential backup
C) Incremental backup
D) Synthetic full backup
Answer: B
Explanation:
A full backup captures all files and resets archive bits, providing a complete snapshot of the system. This method ensures simple recovery but requires significant storage and longer backup windows.
Incremental backup copies files changed since the last backup (full or incremental) and resets the archive bit. It minimizes storage and time per backup but requires all incremental backups since the last full backup for recovery.
Synthetic full backup combines full and incremental backups to produce a new full backup without reading all data from the source. It optimizes recovery speed but involves more complex management.
Differential backup copies all files changed since the last full backup without resetting the archive bit. Each differential backup grows cumulatively, capturing changes since the last full backup. Recovery is straightforward, requiring only the last full backup and the latest differential backup. Differential backups balance speed, storage requirements, and recovery simplicity. They are especially useful when backups must be performed frequently without consuming excessive resources.
Organizations often schedule differential backups between full backups to reduce recovery time and ensure redundancy. While the storage footprint increases over time, modern storage optimization, deduplication, and incremental storage solutions help manage this efficiently. Differential backups also simplify backup verification and auditing processes, ensuring regulatory compliance.
The backup method that copies all changes since the last full backup without altering archive indicators is a Differential backup, making it the correct answer.
Question 140:
Which type of malware appears legitimate to trick users into executing it?
A) Worm
B) Trojan
C) Virus
D) Rootkit
Answer: B
Explanation:
Worms self-propagate across networks without user intervention, exploiting vulnerabilities to spread autonomously. They focus on infection speed rather than disguising themselves as legitimate programs.
Viruses attach to files or programs and replicate when executed, often causing damage or corruption. While viruses require user action for propagation, they do not typically rely on deception to appear legitimate.
Rootkits are designed to conceal malware presence and maintain privileged access, focusing on stealth rather than deception. They often operate at a low level to evade detection.
Trojans, however, rely on deception and social engineering. They masquerade as legitimate software or desirable tools, enticing users to download and execute them. Once installed, Trojans, short for Trojan horses, are a particularly insidious type of malware because they rely on deception rather than exploiting direct system vulnerabilities. Unlike viruses or worms, which can replicate themselves and spread autonomously, Trojans require user action to execute. This could involve opening an email attachment, downloading a seemingly harmless file from the internet, or running pirated software. Once executed, the Trojan can deliver a wide range of malicious payloads, each designed to compromise system security, steal sensitive information, or enable further attacks. Common payloads include keyloggers, which record every keystroke to capture passwords or personal data; ransomware, which encrypts files and demands payment for decryption; spyware, which monitors user activity and transmits it to attackers; and backdoors, which provide remote access to attackers for ongoing control and manipulation of the compromised system.
The effectiveness of Trojans stems from their ability to exploit human trust. Attackers craft these programs to appear legitimate, often mimicking software updates, security tools, or popular applications. This reliance on social engineering makes user awareness a critical component of defense. Organizations that provide ongoing cybersecurity training and phishing simulations help users recognize suspicious emails, links, and downloads, reducing the likelihood of accidental execution of a Trojan. In addition to user awareness, technical defenses play a crucial role. Endpoint protection platforms can identify and block known malicious software, while application whitelisting ensures that only authorized programs can run on devices, preventing unauthorized execution. Regular software updates and patch management close vulnerabilities that malware might exploit indirectly, further reducing risk.
Despite preventative measures, some Trojans may still bypass defenses, making detection and response essential. Security monitoring tools, intrusion detection systems (IDS), and behavioral analysis solutions can identify anomalies indicative of Trojan activity, such as unexpected outbound network traffic, unusual file modifications, or suspicious process behavior. Advanced threat intelligence feeds help security teams stay informed about emerging Trojan variants and tactics, allowing for faster containment and remediation. Furthermore, implementing robust backup strategies ensures that if a Trojan, such as ransomware, successfully encrypts files, organizations can restore data without succumbing to extortion demands.
In summary, Trojans represent a sophisticated malware threat that capitalizes on deception and user trust. Mitigating the risk requires a multi-layered approach, combining user education, technical defenses, proactive monitoring, and incident response preparedness. Recognizing the threat and implementing these measures significantly reduces the chances of compromise and limits potential damage. The malware type specifically designed to trick users by appearing legitimate is a Trojan, making it the correct answer.
Question 141:
Which control type is designed to detect security incidents after they occur?
A) Preventive
B) Deterrent
C) Corrective
D) Detective
Answer: D
Explanation:
Preventive controls are designed to stop security incidents before they occur. These include measures such as access controls, firewalls, encryption, multi-factor authentication, security awareness training, and configuration management. Preventive measures are proactive in nature and aim to eliminate vulnerabilities or block potential threats. However, no matter how comprehensive preventive measures are, some incidents may still occur due to unknown vulnerabilities, human error, or sophisticated attacks.
Deterrent controls are intended to discourage potential attackers or insiders from performing malicious actions. Examples include warning signs, security policies, monitoring notices, and visible surveillance cameras. While deterrent controls influence behavior and can reduce the likelihood of incidents, they do not detect or respond to events once they have occurred.
Corrective controls focus on restoring systems, applications, or data to a secure or operational state after an incident has taken place. These controls include backups, patching processes, system restoration procedures, and malware removal tools. Corrective measures ensure that operations can resume with minimal impact, but they do not provide immediate identification or alerting when an incident occurs.
Detective controls, on the other hand, are explicitly designed to identify and alert organizations about security events as they happen or shortly after they occur. Examples include intrusion detection systems (IDS), security information and event management (SIEM) tools, audit logs, anomaly detection systems, and network traffic monitoring. These controls provide visibility into actual security incidents and can help security teams respond quickly to mitigate damage, analyze attack patterns, and prevent future occurrences.
Detective controls are essential because even organizations with strong preventive and deterrent measures may still face threats from sophisticated attacks, insider misuse, or configuration errors. They complement preventive and corrective measures by offering the necessary insight into real-time or historical events. Furthermore, detective controls provide critical evidence for compliance audits, forensic investigations, and regulatory reporting.
An effective security strategy incorporates preventive, detective, and corrective controls together in a layered approach. While preventive controls reduce the likelihood of incidents, detective controls ensure that no event goes unnoticed, and corrective controls restore integrity when incidents occur. Implementing detective controls helps organizations meet security standards such as ISO 27001, NIST frameworks, and industry-specific compliance requirements.
The control type designed to identify security incidents after they occur is Detective, making it the correct answer.
Question 142:
Which access control model assigns permissions based on job responsibilities within an organization?
A) Discretionary Access Control
B) Mandatory Access Control
C) Role-Based Access Control
D) Rule-Based Access Control
Answer: C
Explanation:
Discretionary Access Control (DAC) allows resource owners to decide who can access specific objects such as files, applications, or databases. This model provides flexibility but relies heavily on user discretion, which can lead to inconsistent security practices and potential overexposure of sensitive information.
Mandatory Access Control (MAC) enforces access restrictions based on centrally managed labels or classifications, such as security clearance levels. Users cannot override these controls, and access decisions are determined by policies set by administrators or system architects. MAC is commonly used in highly regulated or classified environments, including government and military settings.
Rule-Based Access Control (RBAC) assigns access based on predefined conditions, such as time of day, location, or device type. While useful for enforcing context-aware access, RBAC is limited to conditional rules and does not inherently assign permissions based on job responsibilities.
Role-Based Access Control (RBAC) provides access permissions aligned directly with organizational roles and job functions. Users are assigned roles, and each role is mapped to a set of permissions granting access to necessary resources. This approach simplifies administration by allowing bulk assignment of privileges to roles rather than individual users. It also enforces the principle of least privilege, as employees receive only the access needed to perform their specific job functions.
RBAC improves security consistency and reduces errors in access management. It supports auditing and compliance by making it easier to review role permissions and detect inappropriate or excessive access. RBAC is widely implemented in enterprise systems, identity and access management solutions, cloud environments, and enterprise resource planning systems.
By defining permissions at the role level, RBAC allows organizations to respond efficiently to staffing changes, promotions, or temporary assignments without individually modifying access for each user. It ensures a scalable, maintainable access control strategy suitable for medium to large organizations where multiple users share common responsibilities.
The access control model that assigns permissions based on job functions is Role-Based Access Control, making it the correct answer.
Question 143:
Which disaster recovery metric defines the acceptable amount of data loss?
A) Recovery Time Objective
B) Recovery Point Objective
C) Maximum Tolerable Downtime
D) Mean Time to Repair
Answer: B
Explanation:
Recovery Time Objective (RTO) defines the maximum acceptable duration for restoring a system or application after an outage. It focuses on downtime and business continuity, but does not specify data loss tolerance. Organizations use RTO to determine backup strategies, failover solutions, and recovery procedures.
Maximum Tolerable Downtime (MTD) represents the longest period an organization can continue to operate without critical services before experiencing significant financial, operational, or reputational damage. MTD influences RTO and overall disaster recovery planning, but is not a direct measure of data loss.
Mean Time to Repair (MTTR) measures the average time required to repair a failed component, system, or process. While it is relevant for operational maintenance and reliability, it does not address the amount of data that can be lost during a disaster.
Recovery Point Objective (RPO) specifies the maximum acceptable amount of data loss measured in time. It defines the point in time to which data must be restored after a disruption to meet business requirements. For example, an RPO of four hours means that in the event of an outage, data recovery must ensure no more than four hours of information is lost. RPO drives the frequency of backups, replication strategies, and data protection measures, ensuring organizations can meet operational continuity requirements.
Determining the appropriate RPO involves balancing storage costs, backup frequency, business impact, and recovery capabilities. Organizations with mission-critical systems or highly dynamic data often require near-zero RPO, necessitating continuous replication or real-time backup solutions. Non-critical systems may tolerate longer RPOs, allowing less frequent backups to reduce resource usage.
By clearly defining RPO, organizations ensure a strategic approach to data protection, compliance, and disaster recovery planning. It is an essential metric for risk assessment, IT service management, and enterprise continuity frameworks.
The disaster recovery metric that defines the acceptable data loss is Recovery Point Objective, making it the correct answer.
Question 144:
Which cloud deployment model shares infrastructure among several organizations with similar requirements?
A) Public Cloud
B) Private Cloud
C) Hybrid Cloud
D) Community Cloud
Answer: D
Explanation:
Public Cloud services, such as Amazon Web Services, Microsoft Azure, or Google Cloud, are available to the general public and are shared across multiple tenants. While cost-effective and scalable, they do not offer the tailored governance or compliance alignment needed by organizations with specific regulatory or security requirements.
Private Cloud serves a single organization exclusively. It can be hosted on-premises or by a third-party provider. Private clouds offer greater control, customization, and security but may incur higher costs due to dedicated resources.
Hybrid Cloud combines private and public cloud resources, enabling organizations to optimize cost, performance, and flexibility. Hybrid clouds allow sensitive workloads to remain on private infrastructure while leveraging public cloud for non-sensitive or elastic workloads.
Community Cloud is designed for multiple organizations with similar objectives, compliance needs, or security requirements. Participants share infrastructure, resources, and costs, while governance policies ensure collective control and compliance with industry or regulatory standards. This model fosters collaboration, efficiency, and resource optimization, making it suitable for sectors such as healthcare, education, government agencies, or research consortia. Community clouds strike a balance between the cost-effectiveness of public clouds and the control of private clouds, providing shared benefits without sacrificing compliance or security.
Community clouds may implement unified security policies, auditing, and identity management, supporting regulatory requirements like HIPAA, FERPA, or GDPR. By pooling resources, organizations reduce operational costs, accelerate deployment of shared applications, and gain access to advanced cloud features without building separate infrastructures.
The cloud deployment model that shares infrastructure among organizations with similar needs is Community Cloud, making it the correct answer.
Question 145:
Which testing methodology evaluates a system from the outside without knowledge of internal structures?
A) White-box Testing
B) Gray-box Testing
C) Black-box Testing
D) Static Code Analysis
Answer: C
Explanation:
White-box Testing evaluates systems with full knowledge of internal code, logic, and architecture. Testers understand data flow, control structures, and system components. It is effective for uncovering hidden vulnerabilities, optimizing performance, and validating security controls, but requires detailed internal information.
Gray-box Testing blends partial internal knowledge with external testing. It is used when testers have limited insight into system design, allowing them to target specific modules or interfaces while simulating external attacker behavior.
Static Code Analysis reviews source code without executing it, detecting potential security flaws, coding errors, and policy violations. It is preventive in nature and focuses on identifying vulnerabilities before deployment.
Black-box Testing evaluates the system purely from an external perspective, without knowledge of internal workings. It simulates how end-users or attackers interact with the system, focusing on inputs, outputs, functionality, and behavior. Black-box testing is essential for penetration testing, functional validation, user acceptance testing, and security evaluation, where internal design details are unknown or unavailable.
This methodology helps identify functional errors, interface issues, security misconfigurations, and unexpected behaviors in real-world scenarios. It ensures that testing reflects realistic operational conditions and validates that the system meets its intended requirements. Black-box testing is a critical component of security assessments, as it mimics the viewpoint of an external attacker, emphasizing observable system vulnerabilities and potential exploits.
The testing methodology that evaluates systems solely from an external perspective is Black-box Testing, making it the correct answer.
Question 146:
Which authentication factor relies on something the user knows?
A) Password
B) Token
C) Biometric
D) Smart Card
Answer: A
Explanation:
Authentication factors are generally divided into three main categories: something you know, something you have, and something you are. Knowledge-based authentication, or something you know, relies on information that only the legitimate user is expected to know. The most common example is a password, which can be a string of characters, a passphrase, or a combination of letters, numbers, and symbols. Other knowledge-based methods include personal identification numbers (PINs), security questions, or answers to personal prompts that are unique to the individual user.
Tokens are physical devices or software-based codes that generate time-based or challenge-response codes, representing something the user possesses. Examples include hardware key fobs, mobile authentication apps, and OTP devices. Tokens ensure that possession of a physical item is required in addition to knowledge, making them part of multifactor authentication rather than knowledge-based authentication alone.
Biometric authentication relies on unique biological traits of the user, such as fingerprints, iris patterns, facial recognition, voice recognition, or behavioral characteristics like typing patterns. Biometrics represent something the user is and provide a highly individualized authentication mechanism that is difficult to replicate or share.
Smart Cards are physical credentials containing embedded cryptographic information, digital certificates, or secure keys. They also represent something the user possesses and are often combined with PINs or passwords for multifactor authentication. Smart Cards provide strong identity verification but require the user to physically carry and manage the card, unlike knowledge-based factors.
Passwords and knowledge-based methods function on the assumption that only the authorized user knows the secret information. They are easy to implement, inexpensive, and widely used across systems. However, they are susceptible to attacks such as phishing, keylogging, social engineering, and brute-force attacks. Strong password policies, multi-factor authentication, and user training help mitigate these risks.
Knowledge-based authentication remains a cornerstone of modern identity verification, especially when combined with other factors for multifactor authentication. It is a flexible and scalable approach that works for most online services, enterprise systems, and secure access environments. By verifying information known only to the user, passwords effectively enforce access control and protect resources without requiring additional hardware or biometric inputs.
The authentication factor relying on information the user knows is the Password, making it the correct answer.
Question 147:
Which attack floods a system with excessive traffic to disrupt service?
A) Phishing
B) Denial-of-Service
C) SQL Injection
D) Man-in-the-Middle
Answer: B
Explanation:
Phishing attacks aim to manipulate users into revealing sensitive information such as login credentials, financial data, or personal details. These attacks exploit human behavior and trust rather than targeting system resources directly.
SQL Injection attacks exploit vulnerabilities in database query input handling. Attackers insert malicious SQL statements into input fields or application requests, potentially gaining unauthorized access to data, modifying records, or bypassing authentication.
Man-in-the-Middle attacks intercept communications between two parties to capture, alter, or inject data without the knowledge of the participants. MitM attacks compromise confidentiality and integrity but do not inherently flood systems with traffic.
Denial-of-Service (DoS) attacks aim to disrupt the normal operation of systems, networks, or services by overwhelming them with excessive traffic or resource requests. The goal is to prevent legitimate users from accessing services, causing downtime, degraded performance, or cascading failures in dependent systems. DoS attacks can target bandwidth, memory, CPU, or application resources, and may range from simple single-source attacks to more complex distributed denial-of-service (DDoS) attacks that use multiple compromised systems or botnets to amplify the effect.
Mitigation strategies include traffic filtering, rate limiting, redundant network architecture, intrusion prevention systems, and cloud-based scrubbing services. Monitoring network traffic, establishing baselines, and implementing early warning detection also help organizations respond effectively to DoS attacks. DoS attacks are a major threat to critical infrastructure, online services, e-commerce platforms, and cloud-based applications, potentially resulting in financial loss, reputational damage, and operational disruption.
The attack that floods systems with excessive traffic to cause disruption is Denial-of-Service, making it the correct answer.
Question 148:
Which digital security mechanism ensures the sender cannot deny sending a message?
A) Encryption
B) Digital Signature
C) Hashing
D) Symmetric Key
Answer: B
Explanation:
Encryption protects the confidentiality of information by converting plaintext into ciphertext, ensuring that unauthorized parties cannot read the content. While encryption secures communication, it does not provide proof of the sender’s identity or non-repudiation.
Hashing transforms data into a fixed-length value, ensuring integrity. A hash allows the recipient to verify that the content has not been altered, but it does not provide authentication of the sender.
Symmetric key encryption uses a shared secret key to encrypt and decrypt data. While it ensures confidentiality and can protect integrity when combined with message authentication codes, it cannot prove the origin of a message or prevent a sender from denying transmission.
Digital signatures are cryptographic constructs that bind the sender’s identity to a message. They are created using the sender’s private key, and the recipient can verify the signature using the sender’s public key. This provides authenticity, integrity, and non-repudiation, meaning the sender cannot deny having sent the message. Digital signatures are widely used in secure email (such as S/MIME), legal documents, electronic contracts, and blockchain transactions. They are essential in environments where accountability, trust, and legal compliance are critical.
Digital signatures are a foundational element of modern cybersecurity and data integrity because they provide both authentication and non-repudiation. Non-repudiation is the guarantee that the sender of a message or document cannot later deny having sent it, which is crucial in legal, financial, and regulatory contexts. Digital signatures achieve this by using asymmetric cryptography, where a private key is used to create the signature and a corresponding public key is used by recipients to verify it. If the signed data is altered in any way after signing, the verification process fails, immediately alerting the recipient to tampering or corruption. This feature is especially valuable in environments where sensitive information, such as contracts, financial transactions, or confidential communications, must be transmitted securely.
Organizations rely on digital signatures to enforce trust and accountability in both internal and external communications. By ensuring that documents and messages can be verified for authenticity, digital signatures help prevent fraud, impersonation, and unauthorized modifications. Many industries, including banking, healthcare, and government, require the use of digital signatures to comply with regulatory frameworks such as the U.S. ESIGN Act, the Uniform Electronic Transactions Act (UETA), or the European Union’s eIDAS regulation. These standards recognize digital signatures as legally binding, giving electronic documents the same weight as traditional handwritten signatures.
In addition to regulatory compliance, digital signatures enhance overall cybersecurity posture. They can be combined with encryption to protect confidentiality while ensuring authenticity and integrity, creating a robust mechanism for secure digital communication. Advanced implementations may also include timestamping, which proves when a signature was created, further strengthening accountability and legal defensibility. The widespread adoption of digital signatures in email, software distribution, and online transactions reflects their importance in maintaining trust in the digital ecosystem.
In summary, digital signatures serve multiple critical functions: they authenticate the sender, protect data integrity, prevent tampering, and provide legal non-repudiation. The digital security mechanism that ensures the sender cannot deny sending a message is a Digital Signature, making it the correct answer.
Question 149:
Which cloud service model provides the highest level of administrative control?
A) Infrastructure as a Service
B) Platform as a Service
C) Software as a Service
D) Function as a Service
Answer: A
Explanation:
Platform as a Service (PaaS) abstracts the underlying operating system, runtime, and infrastructure. Users manage applications and data but have limited control over the server, network, or storage configurations. This allows faster development and deployment but reduces administrative flexibility.
Software as a Service (SaaS) provides fully managed applications. Users typically have minimal control, limited to configuration options within the application itself. SaaS is convenient and scalable, but unsuitable for organizations needing deep administrative access.
Function as a Service (FaaS) is a serverless computing model where users deploy individual functions or code snippets that execute in response to specific events or triggers, such as HTTP requests, database updates, or messaging queue events. The cloud provider abstracts and manages the underlying infrastructure, including servers, storage, networking, runtime environments, scaling, and maintenance. This allows developers to focus entirely on the application logic rather than on infrastructure management. FaaS is particularly suited for microservices, event-driven applications, and tasks that require rapid execution with variable loads. Because the platform automatically provisions resources as needed, it provides elasticity and cost efficiency, billing users only for actual compute time used. However, the trade-off is that FaaS provides very limited administrative control. Users cannot directly configure servers, networking, or underlying operating systems, which may limit customization, fine-grained security settings, or advanced configuration options.
Infrastructure as a Service (IaaS), in contrast, provides the highest level of administrative control among cloud service models. With IaaS, users are given virtualized computing resources such as virtual machines, storage volumes, and network components. They are responsible for managing the operating systems, software applications, network configurations, and security controls on these virtual resources. The cloud provider only handles the physical hardware, the underlying virtualization layer, and basic resource availability. This level of control allows organizations to configure their environment exactly as required, including installing specialized software, setting firewall rules, managing load balancers, or implementing custom logging and monitoring solutions.
IaaS enables enterprises to implement flexible deployment architectures that closely resemble traditional on-premises infrastructure but with the advantages of cloud scalability, redundancy, and geographic distribution. Organizations can enforce customized security policies, such as defining identity and access management rules, encrypting storage volumes, implementing network segmentation, or integrating with their existing security information and event management systems. It also supports compliance with industry standards, regulatory requirements, and internal governance practices, as administrators retain control over how systems are configured, monitored, and maintained.
For organizations requiring high levels of control, IaaS is ideal because it bridges the gap between traditional infrastructure management and the benefits of cloud computing. Enterprises can leverage cloud elasticity, automated resource provisioning, and high availability while retaining full authority over the operating environment. Unlike PaaS or SaaS, where the platform provider abstracts significant portions of management, IaaS allows for deep customization and operational flexibility. It is also well-suited for hybrid cloud deployments, legacy application migration, disaster recovery, and scenarios that require specialized configurations not supported by higher-level cloud models.
The cloud service model that provides the highest administrative control is Infrastructure as a Service, making it the correct answer. By offering full control over virtual resources, operating systems, applications, and network configurations, IaaS empowers organizations to implement advanced infrastructure strategies while benefiting from cloud scalability, reliability, and resource efficiency. It provides the balance of autonomy and managed service that many large enterprises and regulated industries require for mission-critical workloads.
Question 150:
Which cryptographic attack uses precomputed hash-value pairs to reverse hashed data?
A) Brute-force attack
B) Rainbow Table attack
C) Man-in-the-Middle
D) Replay attack
Answer: B
Explanation:
Brute-force attacks attempt every possible combination of characters or keys to crack passwords or cryptographic hashes. This method guarantees success but is resource-intensive and time-consuming.
Man-in-the-Middle attacks intercept communications between parties to capture, alter, or inject data. While they compromise confidentiality and integrity, they do not rely on precomputed tables.
Replay attacks capture valid data transmissions and retransmit them to gain unauthorized access. Replay attacks focus on communication interception and reuse rather than reversing hashed data.
Rainbow Table attacks utilize precomputed tables mapping plaintext inputs to their corresponding hash values. When an attacker obtains a hash, they compare it against the table to efficiently find the original input, dramatically reducing the time needed compared to brute-force attacks. Rainbow tables are particularly effective against unsalted hashes because identical inputs always produce the same hash output. Without randomization, attackers can reuse the same precomputed tables across multiple systems or users, making the attack both scalable and efficient.
Salting hashes by adding random data to the input before hashing effectively mitigates rainbow table attacks. Each unique salt generates a distinct hash, even if the original input (such as a password) is identical. For example, two users with the same password will have different hashed values when unique salts are applied. This renders precomputed tables ineffective, as each hash would require its own table, which is computationally and storage-wise impractical for attackers. Salting is therefore considered a fundamental best practice in secure password storage.
Rainbow Table attacks are widely studied in cryptography, penetration testing, and cybersecurity education because they illustrate the vulnerabilities inherent in weak hashing practices. They highlight the risks of relying on fast, unsalted hash functions like MD5 or SHA-1, which can be computed extremely quickly and are susceptible to precomputation attacks. Modern security standards recommend using slow, memory-intensive hashing algorithms like bcrypt, scrypt, or Argon2. These functions intentionally require more computational effort to generate a hash, making the creation of rainbow tables infeasible and slowing brute-force attempts significantly.
In practical terms, rainbow table attacks are used by attackers who have gained access to a hashed password database but do not have direct access to plaintext credentials. For example, in a data breach scenario, an attacker may obtain a leaked database of hashed passwords. By leveraging rainbow tables, they can reverse the hashes and recover the original passwords for use in credential stuffing, unauthorized account access, or lateral movement across systems. This emphasizes the importance of combining secure hashing with additional measures such as multi-factor authentication and account lockout policies to further mitigate risk.
Organizations implementing robust password security strategies will also enforce minimum password complexity requirements, avoid common passwords, and rotate passwords periodically. These measures, combined with strong salted and iteratively hashed passwords, make rainbow table attacks practically ineffective. Awareness of this attack also drives security research into password cracking resistance, encouraging improvements in hashing algorithms, key stretching techniques, and adaptive security protocols that evolve in response to emerging threats.
Rainbow Table attacks not only serve as a cautionary example for organizations but also provide valuable learning opportunities for security professionals. Understanding the mechanics of precomputed hash attacks reinforces the importance of cryptographic best practices, such as salting, iterative hashing, and secure storage of secrets. Moreover, studying rainbow tables helps penetration testers simulate real-world attack scenarios and develop defensive strategies to protect sensitive data.
Rainbow table attacks are cryptographic attacks that leverage precomputed tables of hash-value pairs to reverse hashes and obtain original plaintext data. Their effectiveness is largely dependent on the absence of salting and the use of fast hash functions. By incorporating unique salts, slow hashing algorithms, and multi-layered authentication mechanisms, organizations can defend against rainbow table attacks, protect user credentials, and ensure compliance with modern security standards. The cryptographic attack that reverses hashes using precomputed tables is the Rainbow Table attack, making it the correct answer.