1. Which of the following is the most common authentication weakness in IoT devices?
A) Biometric authentication
B) Hardcoded credentials
C) Multi-factor authentication
D) OAuth-based authentication
Answer: B) Hardcoded credentials
Explanation: Many IoT devices come with default usernames and passwords, often hardcoded in firmware. Attackers can easily exploit these credentials, especially if users don’t change them.
2. What is a common tool used to brute-force authentication on IoT devices?
A) Nmap
B) Hydra
C) Wireshark
D) Nikto
Answer: B) Hydra
Explanation: Hydra is a fast and powerful password-cracking tool used to perform brute-force attacks on IoT device authentication systems.
3. Why are weak passwords a significant security risk for IoT devices?
A) They increase device speed
B) They allow unauthorized access
C) They improve device functionality
D) They make firmware updates easier
Answer: B) They allow unauthorized access
Explanation: Weak passwords make it easier for attackers to guess credentials using brute-force or dictionary attacks, leading to unauthorized access and potential device compromise.
4. Which attack technique involves guessing common passwords for IoT devices?
A) Dictionary attack
B) Man-in-the-middle attack
C) ARP spoofing
D) SQL Injection
Answer: A) Dictionary attack
Explanation: A dictionary attack systematically attempts common or leaked passwords to gain unauthorized access to IoT devices.
5. What is the primary purpose of multi-factor authentication (MFA) in IoT security?
A) To slow down login attempts
B) To require multiple devices
C) To add an additional security layer
D) To replace passwords
Answer: C) To add an additional security layer
Explanation: MFA enhances security by requiring multiple authentication factors, such as a password and a one-time code, reducing the risk of weak password exploitation.
6. What is the default Telnet port commonly used in IoT devices?
A) 21
B) 22
C) 23
D) 80
Answer: C) 23
Explanation: Telnet (port 23) is often enabled in IoT devices, allowing remote access. Attackers exploit weak or default Telnet passwords to gain unauthorized control.
7. Which attack involves intercepting and modifying IoT authentication traffic?
A) MITM attack
B) SQL Injection
C) Cross-site scripting (XSS)
D) Brute-force attack
Answer: A) MITM attack
Explanation: A Man-in-the-Middle (MITM) attack allows attackers to intercept and alter authentication data, leading to unauthorized access.
8. What is a simple way to mitigate brute-force attacks on IoT devices?
A) Disabling firmware updates
B) Using CAPTCHA or account lockout mechanisms
C) Using plain-text passwords
D) Disabling encryption
Answer: B) Using CAPTCHA or account lockout mechanisms
Explanation: Implementing account lockout policies or CAPTCHA can prevent brute-force attacks by limiting the number of incorrect login attempts.
9. What protocol is commonly used for IoT device authentication?
A) MQTT
B) SMB
C) FTP
D) Telnet
Answer: A) MQTT
Explanation: MQTT (Message Queuing Telemetry Transport) is a lightweight communication protocol used in IoT. Poorly configured authentication in MQTT can be exploited.
10. Which tool can be used to scan for open authentication ports on IoT devices?
A) Metasploit
B) Nmap
C) Burp Suite
D) Ettercap
Answer: B) Nmap
Explanation: Nmap is a network scanning tool that helps identify open ports, including authentication ports that attackers can target.
11. Why is default authentication dangerous in IoT devices?
A) Users don’t know their own passwords
B) Default credentials are publicly available
C) It improves usability
D) It prevents unauthorized access
Answer: B) Default credentials are publicly available
Explanation: Many IoT devices ship with default usernames and passwords, which can be found in public device manuals or leaked credential lists, making them easy targets.
12. What is an effective way to secure IoT authentication?
A) Use factory-default passwords
B) Disable HTTPS
C) Implement strong password policies and MFA
D) Store passwords in plain text
Answer: C) Implement strong password policies and MFA
Explanation: Strong password policies and Multi-Factor Authentication (MFA) significantly enhance security by making unauthorized access harder.
13. Which of the following is an IoT device vulnerability related to authentication?
A) Buffer overflow
B) Hardcoded credentials
C) Ransomware
D) DNS Spoofing
Answer: B) Hardcoded credentials
Explanation: Many IoT devices have hardcoded credentials in their firmware, making them vulnerable to attacks if discovered.
14. What is the primary risk of using unencrypted authentication in IoT devices?
A) Slow network speed
B) Data loss
C) Credentials can be intercepted in transit
D) Increased battery usage
Answer: C) Credentials can be intercepted in transit
Explanation: If authentication traffic is not encrypted, attackers can sniff credentials using packet capture tools like Wireshark.
15. Which security measure can prevent brute-force login attempts?
A) Enabling guest access
B) Blocking IP addresses after failed login attempts
C) Allowing unlimited login retries
D) Disabling encryption
Answer: B) Blocking IP addresses after failed login attempts
Explanation: Rate-limiting and blocking IPs after multiple failed attempts reduce the effectiveness of brute-force attacks.
16. What role does TLS play in securing IoT authentication?
A) Encrypts authentication traffic
B) Blocks malware
C) Prevents brute-force attacks
D) Blocks phishing emails
Answer: A) Encrypts authentication traffic
Explanation: Transport Layer Security (TLS) encrypts authentication requests, preventing credentials from being intercepted.
17. Which security standard is recommended for IoT authentication?
A) WPA3
B) WEP
C) Telnet
D) HTTP
Answer: A) WPA3
Explanation: WPA3 offers stronger encryption and authentication for IoT device security, making it the recommended standard.
18. What is a major risk of IoT device APIs with weak authentication?
A) Attackers can remotely control devices
B) Improved device performance
C) Faster connection speeds
D) More efficient data storage
Answer: A) Attackers can remotely control devices
Explanation: Weak API authentication allows attackers to remotely hijack IoT devices, leading to security breaches.
19. Why should SSH be used instead of Telnet for authentication?
A) SSH is easier to configure
B) Telnet encrypts data better
C) SSH provides encrypted communication
D) Telnet is faster
Answer: C) SSH provides encrypted communication
Explanation: SSH encrypts authentication data, unlike Telnet, which transmits credentials in plaintext.
20. Which measure helps prevent credential stuffing attacks on IoT devices?
A) Disabling firewalls
B) Using unique passwords for each device
C) Enabling default passwords
D) Allowing anonymous access
Answer: B) Using unique passwords for each device
Explanation: Credential stuffing attacks rely on reused passwords; using unique passwords mitigates the risk.
21. What is the primary reason IoT devices are more vulnerable to authentication attacks than traditional computing devices?
A) They have stronger encryption
B) They often lack security updates and patches
C) They use AI for authentication
D) They always require biometric authentication
Answer: B) They often lack security updates and patches
Explanation: Many IoT devices lack regular firmware updates, leaving them vulnerable to known authentication exploits.
22. What is the risk of using factory-default credentials in IoT devices?
A) They improve device security
B) They can be easily guessed or found in public databases
C) They make device configuration easier
D) They increase processing power
Answer: B) They can be easily guessed or found in public databases
Explanation: Default credentials are often publicly known and used by attackers for automated brute-force attacks.
23. Which of the following authentication mechanisms is the weakest for IoT devices?
A) Certificate-based authentication
B) Password-based authentication with default credentials
C) Biometric authentication
D) Two-factor authentication
Answer: B) Password-based authentication with default credentials
Explanation: Default passwords are easily exploited, making them one of the weakest authentication mechanisms.
24. What is a common technique used by attackers to discover IoT devices with weak authentication on the internet?
A) SQL Injection
B) Shodan search
C) DNS Spoofing
D) DDoS attack
Answer: B) Shodan search
Explanation: Shodan is a search engine for internet-connected devices, allowing attackers to find vulnerable IoT devices with weak authentication.
25. What authentication-related vulnerability is commonly found in MQTT-based IoT devices?
A) Plaintext credentials in transit
B) SQL Injection
C) DNS Cache Poisoning
D) XSS (Cross-Site Scripting)
Answer: A) Plaintext credentials in transit
Explanation: Many MQTT brokers do not use encryption, allowing attackers to sniff credentials in plaintext.
26. What type of authentication is preferred for securing IoT APIs?
A) API keys exposed in URLs
B) OAuth 2.0 with token-based authentication
C) No authentication for public APIs
D) Plaintext username and password
Answer: B) OAuth 2.0 with token-based authentication
Explanation: OAuth 2.0 and token-based authentication enhance security by preventing credential exposure and replay attacks.
27. Which attack technique exploits repeated use of the same credentials across different IoT devices?
A) Man-in-the-middle attack
B) Credential stuffing
C) SQL Injection
D) Phishing
Answer: B) Credential stuffing
Explanation: Attackers use previously leaked credentials to attempt logins across multiple IoT devices, leveraging users’ habit of reusing passwords.
28. What protocol should be avoided for authentication due to its lack of encryption?
A) SSH
B) Telnet
C) HTTPS
D) TLS
Answer: B) Telnet
Explanation: Telnet transmits credentials in plaintext, making it an insecure choice for authentication.
29. Why are biometric authentication methods less commonly used in IoT devices?
A) They are difficult to implement on resource-constrained devices
B) They are less secure than passwords
C) They require Telnet
D) They are cheaper than passwords
Answer: A) They are difficult to implement on resource-constrained devices
Explanation: IoT devices often have limited processing power and storage, making biometric authentication harder to implement.
30. What is a simple but effective way to strengthen authentication security in IoT devices?
A) Keep factory-default passwords
B) Implement account lockout policies
C) Allow anonymous login
D) Disable encryption
Answer: B) Implement account lockout policies
Explanation: Locking an account after multiple failed login attempts helps prevent brute-force attacks.
31. What is a major drawback of using hardcoded credentials in IoT firmware?
A) They increase processing power
B) They prevent unauthorized access
C) Attackers can extract them from firmware dumps
D) They improve user experience
Answer: C) Attackers can extract them from firmware dumps
Explanation: Hardcoded credentials can be retrieved from firmware images, allowing attackers to compromise multiple devices.
32. What type of attack occurs when an attacker captures and reuses an authentication token to gain unauthorized access?
A) Brute-force attack
B) Session hijacking
C) SQL Injection
D) Phishing
Answer: B) Session hijacking
Explanation: Session hijacking involves intercepting authentication tokens and reusing them to impersonate a legitimate user.
33. Which attack technique involves exploiting unprotected HTTP Basic Authentication in IoT devices?
A) Brute-force attack
B) MITM attack
C) Phishing
D) XML Injection
Answer: B) MITM attack
Explanation: HTTP Basic Authentication transmits credentials in base64 encoding, making them susceptible to interception in a Man-in-the-Middle (MITM) attack.
34. Why is asymmetric encryption beneficial for IoT authentication?
A) It uses the same key for encryption and decryption
B) It allows secure key exchange even over an insecure channel
C) It requires no encryption
D) It is faster than symmetric encryption
Answer: B) It allows secure key exchange even over an insecure channel
Explanation: Asymmetric encryption (e.g., RSA, ECC) enables secure authentication and key exchange, even on insecure networks.
35. What is an example of a weak authentication practice in IoT devices?
A) Using AES encryption for passwords
B) Implementing two-factor authentication
C) Using default credentials without forcing a password change
D) Using token-based authentication
Answer: C) Using default credentials without forcing a password change
Explanation: If users are not forced to change default passwords, attackers can easily exploit them.
36. What type of authentication is considered more secure for IoT devices?
A) Single-factor authentication
B) Multi-factor authentication (MFA)
C) Hardcoded password authentication
D) Plaintext authentication
Answer: B) Multi-factor authentication (MFA)
Explanation: MFA requires multiple verification methods, making authentication more resistant to attacks.
37. Which of the following can improve authentication security in IoT devices?
A) Disabling HTTPS
B) Using TLS encryption for login credentials
C) Storing passwords in plaintext
D) Allowing unlimited login attempts
Answer: B) Using TLS encryption for login credentials
Explanation: TLS encrypts login data, preventing attackers from sniffing credentials.
38. What is the risk of using weak password hashing algorithms in IoT devices?
A) They slow down authentication
B) They make passwords easy to crack if leaked
C) They improve device performance
D) They prevent brute-force attacks
Answer: B) They make passwords easy to crack if leaked
Explanation: Weak hashing algorithms like MD5 can be easily cracked, exposing stored passwords.
39. Why is using unique passwords for each IoT device important?
A) Prevents attackers from using one compromised password across multiple devices
B) Makes logging in more difficult
C) Increases network latency
D) Reduces device performance
Answer: A) Prevents attackers from using one compromised password across multiple devices
Explanation: Unique passwords prevent credential reuse attacks.
40. What is a common security best practice when designing authentication for IoT devices?
A) Hardcoding usernames and passwords
B) Using strong, unique passwords with MFA
C) Storing credentials in plaintext
D) Allowing public access to authentication endpoints
Answer: B) Using strong, unique passwords with MFA
Explanation: Strong passwords + MFA significantly reduce the risk of unauthorized access in IoT devices.
41. Which of the following is a major authentication flaw in many IoT devices?
A) Using end-to-end encryption
B) Storing passwords in plaintext
C) Implementing biometric authentication
D) Using time-based one-time passwords (TOTP)
Answer: B) Storing passwords in plaintext
Explanation: Many IoT devices store passwords without encryption, making them easily accessible if the device is compromised.
42. What security risk arises when IoT devices use weak encryption for authentication?
A) Attackers can easily decrypt credentials
B) Faster authentication process
C) Improved battery life
D) Enhanced security
Answer: A) Attackers can easily decrypt credentials
Explanation: Weak encryption (e.g., MD5, SHA-1) can be cracked, exposing authentication credentials to attackers.
43. What is the best practice for IoT device manufacturers to secure authentication?
A) Enforcing strong password policies
B) Allowing only default credentials
C) Disabling authentication entirely
D) Encouraging users to write passwords on the device
Answer: A) Enforcing strong password policies
Explanation: Requiring strong passwords and forcing password changes on first login helps prevent unauthorized access.
44. What happens if an IoT device does not implement proper session management?
A) Attackers can hijack sessions and gain unauthorized access
B) Authentication becomes faster
C) The device consumes less power
D) The device is more user-friendly
Answer: A) Attackers can hijack sessions and gain unauthorized access
Explanation: Poor session management (e.g., lack of session timeouts) allows attackers to reuse session tokens and impersonate users.
45. Which of the following is an effective countermeasure against brute-force attacks on IoT authentication?
A) Using IP whitelisting
B) Enabling unlimited login attempts
C) Using CAPTCHA or account lockout policies
D) Using weak encryption
Answer: C) Using CAPTCHA or account lockout policies
Explanation: CAPTCHA and account lockout policies prevent attackers from attempting multiple login guesses in a brute-force attack.
46. How can attackers exploit IoT devices that use weak authentication?
A) By guessing default or common passwords
B) By overclocking the device
C) By reducing network latency
D) By updating firmware
Answer: A) By guessing default or common passwords
Explanation: Attackers use credential stuffing and brute-force attacks to exploit weak authentication mechanisms in IoT devices.
47. What is a potential risk of using shared credentials across multiple IoT devices?
A) Single point of failure if one credential is compromised
B) Improved security
C) Reduced attack surface
D) Faster authentication process
Answer: A) Single point of failure if one credential is compromised
Explanation: If one device is breached, an attacker can reuse the credentials to access all IoT devices using the same login information.
48. Why is implementing HTTPS important for IoT device authentication?
A) It encrypts authentication traffic
B) It makes authentication slower
C) It increases power consumption
D) It allows attackers to view credentials
Answer: A) It encrypts authentication traffic
Explanation: HTTPS encrypts authentication requests, preventing attackers from intercepting credentials in transit.
49. What is a major vulnerability in IoT authentication when using outdated SSL/TLS protocols?
A) The connection becomes faster
B) The encryption can be easily broken using known exploits
C) It increases device battery life
D) It improves authentication security
Answer: B) The encryption can be easily broken using known exploits
Explanation: Older SSL/TLS protocols (e.g., TLS 1.0) are vulnerable to attacks like BEAST and POODLE, allowing attackers to decrypt authentication traffic.
50. What is the purpose of device fingerprinting in IoT authentication?
A) Identifies devices for secure authentication
B) Slows down authentication
C) Encrypts login credentials
D) Increases CPU usage
Answer: A) Identifies devices for secure authentication
Explanation: Device fingerprinting ensures that only trusted devices can authenticate, reducing the risk of unauthorized access.
51. What is an effective way to prevent authentication bypass in IoT devices?
A) Enforcing multi-factor authentication (MFA)
B) Using default credentials
C) Disabling HTTPS
D) Allowing unlimited login attempts
Answer: A) Enforcing multi-factor authentication (MFA)
Explanation: MFA adds an extra security layer, making it harder for attackers to bypass authentication using stolen credentials.
52. Which tool is commonly used to capture authentication traffic for analysis?
A) Wireshark
B) Metasploit
C) Hashcat
D) Aircrack-ng
Answer: A) Wireshark
Explanation: Wireshark is a network packet analyzer that can capture authentication traffic, allowing attackers to sniff plaintext credentials if encryption is weak.
53. Why is enforcing password complexity important in IoT authentication?
A) Prevents easy password guessing
B) Improves device speed
C) Reduces memory usage
D) Prevents firmware updates
Answer: A) Prevents easy password guessing
Explanation: Complex passwords make it harder for attackers to use brute-force or dictionary attacks to gain unauthorized access.
54. What is the risk of using weak API authentication in IoT devices?
A) Attackers can gain remote access to the device
B) Improved API performance
C) Reduced network latency
D) Increased battery life
Answer: A) Attackers can gain remote access to the device
Explanation: Weak API authentication allows attackers to execute unauthorized commands, potentially compromising IoT devices.
55. Why should IoT device authentication logs be monitored?
A) To detect unauthorized access attempts
B) To improve device performance
C) To increase battery life
D) To store passwords
Answer: A) To detect unauthorized access attempts
Explanation: Monitoring authentication logs helps identify suspicious login attempts, allowing early detection of attacks.
56. Which attack method targets IoT devices by repeatedly guessing authentication credentials?
A) Brute-force attack
B) Phishing
C) DNS poisoning
D) Session hijacking
Answer: A) Brute-force attack
Explanation: Brute-force attacks involve systematically guessing username-password combinations until access is gained.
57. Why should IoT devices avoid using static session tokens?
A) Attackers can reuse them to gain unauthorized access
B) They improve performance
C) They reduce authentication time
D) They prevent unauthorized access
Answer: A) Attackers can reuse them to gain unauthorized access
Explanation: Static session tokens do not expire, making them vulnerable to hijacking attacks.
58. What is the best way to store authentication credentials securely on IoT devices?
A) Use salted password hashing algorithms
B) Store credentials in plaintext
C) Use hardcoded credentials
D) Disable authentication
Answer: A) Use salted password hashing algorithms
Explanation: Salting passwords before hashing prevents attackers from using precomputed hash tables (rainbow tables) to crack passwords.
59. What type of attack can exploit insecure authentication on Bluetooth-enabled IoT devices?
A) Bluesnarfing
B) SQL Injection
C) Phishing
D) DDoS
Answer: A) Bluesnarfing
Explanation: Bluesnarfing exploits weak authentication in Bluetooth to steal sensitive data from IoT devices.
60. Which is the most effective way to prevent unauthorized remote access to IoT devices?
A) Disable unnecessary remote access features
B) Use factory-default passwords
C) Allow public access to authentication endpoints
D) Store passwords in plaintext
Answer: A) Disable unnecessary remote access features
Explanation: Disabling unused remote access features reduces the attack surface and prevents unauthorized logins.
61. What is a key reason IoT devices often have weak authentication?
A) Manufacturers prioritize convenience over security
B) IoT devices require complex passwords
C) IoT devices never connect to the internet
D) IoT devices use advanced encryption by default
Answer: A) Manufacturers prioritize convenience over security
Explanation: Many IoT manufacturers prioritize ease of setup over strong security measures, leading to weak authentication mechanisms.
62. What happens when an IoT device lacks proper session expiration?
A) Attackers can reuse an active session to gain unauthorized access
B) The device stops working
C) The user must reauthenticate frequently
D) The device becomes faster
Answer: A) Attackers can reuse an active session to gain unauthorized access
Explanation: Session expiration ensures that active sessions do not persist indefinitely, preventing attackers from hijacking old sessions.
63. Which of the following is an effective countermeasure to prevent unauthorized SSH access on IoT devices?
A) Changing the default SSH port
B) Disabling encryption
C) Using Telnet instead of SSH
D) Allowing anonymous SSH login
Answer: A) Changing the default SSH port
Explanation: Changing the default SSH port makes it harder for automated attacks to identify and target SSH services on IoT devices.
64. What is the primary risk of using public Wi-Fi networks for IoT device authentication?
A) Increased battery usage
B) Risk of Man-in-the-Middle (MITM) attacks
C) Reduced device speed
D) Longer authentication time
Answer: B) Risk of Man-in-the-Middle (MITM) attacks
Explanation: Public Wi-Fi networks are unsecured, allowing attackers to intercept authentication data through MITM attacks.
65. What is a common risk associated with using QR code-based authentication in IoT devices?
A) QR codes can be easily forged
B) QR codes increase device processing power
C) QR codes cannot be used for authentication
D) QR codes improve security
Answer: A) QR codes can be easily forged
Explanation: Fake QR codes can redirect users to phishing sites, leading to credential theft and unauthorized access.
66. What attack exploits weak authentication in IoT smart cameras?
A) Botnet recruitment
B) SQL Injection
C) Cross-site scripting
D) DNS poisoning
Answer: A) Botnet recruitment
Explanation: Weak authentication in IoT smart cameras allows attackers to compromise them and use them in botnets like Mirai to launch large-scale attacks.
67. What is an effective way to protect IoT authentication credentials stored on a device?
A) Use hardware security modules (HSMs)
B) Store credentials in plaintext
C) Disable authentication
D) Allow remote access without authentication
Answer: A) Use hardware security modules (HSMs)
Explanation: HSMs provide secure storage for cryptographic keys and credentials, making them difficult to extract.
68. Which authentication mechanism should be avoided for IoT devices due to security weaknesses?
A) Passwordless authentication
B) Basic HTTP authentication
C) Biometric authentication
D) Public key authentication
Answer: B) Basic HTTP authentication
Explanation: Basic HTTP authentication transmits credentials in Base64 encoding, which can be easily intercepted and decoded.
69. What is a key reason IoT devices should use per-device unique credentials?
A) It prevents a single breach from compromising multiple devices
B) It improves device speed
C) It increases authentication time
D) It allows easy debugging
Answer: A) It prevents a single breach from compromising multiple devices
Explanation: Using unique credentials for each IoT device ensures that one compromised device does not endanger the entire system.
**70. What security flaw occurs when IoT devices use plaintext credential transmission?
A) Credentials can be intercepted over the network
B) Authentication becomes stronger
C) The device operates faster
D) Encryption is improved
Answer: A) Credentials can be intercepted over the network
Explanation: Plaintext transmission of credentials makes authentication vulnerable to network sniffing attacks.
71. Why should IoT authentication logs be centrally monitored?
A) To detect unusual login attempts across multiple devices
B) To reduce authentication times
C) To store all passwords in one place
D) To improve device battery life
Answer: A) To detect unusual login attempts across multiple devices
Explanation: Centralized log monitoring helps identify brute-force attempts, unauthorized logins, and authentication failures.
72. What is a common problem when IoT devices use insecure authentication APIs?
A) Unauthorized access via API endpoints
B) Faster API response times
C) Reduced authentication security risks
D) Improved encryption
Answer: A) Unauthorized access via API endpoints
Explanation: Insecure API authentication allows attackers to bypass authentication and gain control over IoT devices.
73. What technique is used to strengthen password-based authentication in IoT devices?
A) Implementing password hashing with salts
B) Storing passwords in plaintext
C) Using hardcoded passwords
D) Allowing password reuse
Answer: A) Implementing password hashing with salts
Explanation: Salting and hashing passwords makes it significantly harder for attackers to crack credentials.
74. What role does rate limiting play in IoT authentication security?
A) It reduces brute-force attack attempts
B) It speeds up authentication
C) It allows unlimited login attempts
D) It encrypts passwords
Answer: A) It reduces brute-force attack attempts
Explanation: Rate limiting restricts the number of authentication attempts, preventing brute-force attacks.
75. What risk arises if IoT authentication is not properly logged?
A) Attackers can gain access without detection
B) Faster authentication
C) Increased encryption strength
D) More efficient authentication
Answer: A) Attackers can gain access without detection
Explanation: Without authentication logging, unauthorized access attempts remain undetected.
76. Why should IoT devices use client-side certificate authentication?
A) To authenticate trusted devices securely
B) To store passwords in plaintext
C) To allow guest access
D) To reduce authentication times
Answer: A) To authenticate trusted devices securely
Explanation: Client-side certificates ensure that only authorized devices can authenticate to an IoT network.
77. What is a risk of exposing IoT authentication endpoints to the internet?
A) They become a target for brute-force and automated attacks
B) They improve performance
C) They speed up authentication
D) They enhance security
Answer: A) They become a target for brute-force and automated attacks
Explanation: Publicly exposed authentication endpoints are prime targets for password-guessing attacks.
78. Why is OAuth preferred for IoT authentication?
A) It eliminates the need to store credentials on IoT devices
B) It reduces encryption strength
C) It speeds up authentication
D) It simplifies brute-force attacks
Answer: A) It eliminates the need to store credentials on IoT devices
Explanation: OAuth uses tokens instead of passwords, reducing the risk of credential exposure.
79. What is a key feature of Zero Trust Authentication in IoT?
A) Every authentication request is verified, regardless of network location
B) It allows all devices to connect freely
C) It stores credentials in plaintext
D) It disables encryption
Answer: A) Every authentication request is verified, regardless of network location
Explanation: Zero Trust Authentication ensures that every authentication attempt is validated, reducing insider threats.
80. Why should IoT devices enforce periodic password rotation?
A) To limit the impact of compromised credentials
B) To slow down authentication
C) To store passwords in plaintext
D) To improve device performance
Answer: A) To limit the impact of compromised credentials
Explanation: Regular password rotation ensures that stolen credentials become useless over time.
81. What is the impact of using weak authentication in IoT healthcare devices?
A) Patient data can be stolen or manipulated
B) Devices operate more efficiently
C) Authentication time is reduced
D) Devices become more secure
Answer: A) Patient data can be stolen or manipulated
Explanation: Weak authentication in medical IoT devices can lead to data breaches, unauthorized access, and life-threatening cyber attacks.
82. Which of the following is a best practice for securing IoT authentication?
A) Enforcing unique device credentials for each IoT device
B) Allowing guest access without passwords
C) Storing passwords in plaintext
D) Using default factory credentials
Answer: A) Enforcing unique device credentials for each IoT device
Explanation: Unique credentials for each IoT device prevent attackers from using one compromised password to gain access to multiple devices.
83. What is a common mistake in IoT device authentication?
A) Using hardcoded credentials in the firmware
B) Requiring strong passwords
C) Implementing MFA
D) Using OAuth for authentication
Answer: A) Using hardcoded credentials in the firmware
Explanation: Hardcoded credentials can be extracted from firmware dumps, making IoT devices easy targets for attackers.
84. Why should IoT devices avoid using sequential or predictable passwords?
A) They are easy for attackers to guess
B) They improve authentication speed
C) They reduce network congestion
D) They make encryption unnecessary
Answer: A) They are easy for attackers to guess
Explanation: Predictable passwords (e.g., 123456, admin123) can be quickly brute-forced or guessed, leading to unauthorized access.
85. Which attack exploits weak authentication to gain remote control of IoT devices?
A) Remote Code Execution (RCE)
B) Buffer Overflow
C) Denial of Service (DoS)
D) MITM Attack
Answer: A) Remote Code Execution (RCE)
Explanation: RCE attacks exploit weak authentication to execute malicious commands on IoT devices, granting attackers full control.
86. What is an effective way to mitigate dictionary attacks on IoT authentication?
A) Implementing account lockout mechanisms
B) Using the same password for all devices
C) Storing passwords in plaintext
D) Allowing unlimited login attempts
Answer: A) Implementing account lockout mechanisms
Explanation: Account lockout policies prevent repeated login attempts after multiple failures, blocking dictionary attacks.
87. What is the role of API authentication in IoT security?
A) Ensures only authorized users can access IoT services
B) Speeds up API response time
C) Allows all users to access APIs without credentials
D) Reduces the need for encryption
Answer: A) Ensures only authorized users can access IoT services
Explanation: API authentication prevents unauthorized API requests, securing IoT device communication.
88. Why is time-based authentication (TOTP) recommended for IoT security?
A) It generates temporary, unique authentication codes
B) It makes brute-force attacks easier
C) It allows hardcoded passwords
D) It prevents all cyberattacks
Answer: A) It generates temporary, unique authentication codes
Explanation: TOTP authentication generates time-sensitive one-time passwords, reducing credential theft risks.
89. Which IoT attack leverages stolen authentication tokens?
A) Session Hijacking
B) ARP Spoofing
C) Phishing
D) DoS Attack
Answer: A) Session Hijacking
Explanation: Attackers steal active authentication tokens to bypass login credentials and hijack IoT sessions.
90. Why should IoT authentication endpoints be protected with rate limiting?
A) To prevent brute-force and automated attacks
B) To improve device speed
C) To allow unlimited login attempts
D) To store credentials in plaintext
Answer: A) To prevent brute-force and automated attacks
Explanation: Rate limiting helps prevent attackers from repeatedly guessing authentication credentials.
91. What is a security risk of weak authentication in industrial IoT (IIoT) systems?
A) Attackers can disrupt manufacturing operations
B) The system requires stronger encryption
C) IoT devices consume more bandwidth
D) Employees can log in faster
Answer: A) Attackers can disrupt manufacturing operations
Explanation: Weak authentication in IIoT can allow attackers to manipulate or halt industrial processes.
92. What technique prevents unauthorized access after multiple failed IoT authentication attempts?
A) Account lockout policies
B) Allowing default credentials
C) Disabling encryption
D) Using weak passwords
Answer: A) Account lockout policies
Explanation: Locking accounts after repeated failed login attempts prevents attackers from brute-forcing authentication.
93. Which IoT authentication method is more secure than passwords alone?
A) Multi-Factor Authentication (MFA)
B) Plaintext password storage
C) Telnet-based authentication
D) Using short passwords
Answer: A) Multi-Factor Authentication (MFA)
Explanation: MFA requires multiple factors for authentication, making it more resistant to credential attacks.
94. What is an effective method to secure IoT authentication against credential stuffing attacks?
A) Implementing unique, per-device credentials
B) Allowing default credentials
C) Storing passwords in plaintext
D) Disabling encryption
Answer: A) Implementing unique, per-device credentials
Explanation: Unique credentials prevent attackers from reusing leaked credentials across multiple devices.
95. Which tool is commonly used to test authentication security in IoT devices?
A) Hydra
B) Photoshop
C) Nginx
D) VirtualBox
Answer: A) Hydra
Explanation: Hydra is a popular tool for brute-force testing of IoT authentication security.
96. What is the primary risk of using SMS-based authentication in IoT devices?
A) SMS messages can be intercepted by attackers
B) SMS speeds up authentication
C) SMS increases encryption strength
D) SMS prevents all cyberattacks
Answer: A) SMS messages can be intercepted by attackers
Explanation: SIM swapping and SS7 attacks allow attackers to intercept SMS-based authentication codes.
97. Why should IoT authentication be audited regularly?
A) To detect vulnerabilities and unauthorized access attempts
B) To slow down authentication
C) To store passwords in plaintext
D) To increase power consumption
Answer: A) To detect vulnerabilities and unauthorized access attempts
Explanation: Regular security audits help identify authentication weaknesses before attackers exploit them.
98. What is a key risk of weak authentication in smart home IoT devices?
A) Attackers can control IoT devices remotely
B) Smart home devices consume more electricity
C) Authentication speed decreases
D) Devices become more secure
Answer: A) Attackers can control IoT devices remotely
Explanation: Weak authentication allows attackers to gain remote access to smart home devices and manipulate them.
99. What is a recommended authentication best practice for IoT manufacturers?
A) Enforce secure password policies and multi-factor authentication
B) Store passwords in plaintext
C) Use hardcoded credentials
D) Allow guest access by default
Answer: A) Enforce secure password policies and multi-factor authentication
Explanation: Strong password policies and MFA significantly reduce IoT authentication vulnerabilities.
100. Why is continuous monitoring of IoT authentication logs important?
A) To detect suspicious login activities and attacks
B) To improve authentication speed
C) To reduce device power consumption
D) To allow unauthorized access
Answer: A) To detect suspicious login activities and attacks
Explanation: Log monitoring helps detect unauthorized access attempts, failed logins, and brute-force attacks in real time.
101. What is a security risk of using email-based password reset mechanisms for IoT authentication?
A) Attackers can hijack email accounts and reset IoT passwords
B) Email-based resets speed up authentication
C) Email-based authentication improves encryption
D) IoT devices do not support password resets
Answer: A) Attackers can hijack email accounts and reset IoT passwords
Explanation: If an attacker gains access to a user’s email account, they can reset passwords and take over IoT devices.
102. Which authentication method should IoT devices avoid due to its vulnerability to replay attacks?
A) Static password authentication
B) Challenge-response authentication
C) Certificate-based authentication
D) Biometric authentication
Answer: A) Static password authentication
Explanation: Static passwords can be intercepted and replayed by attackers if encryption is not properly implemented.
103. What is an effective way to prevent IoT device authentication token theft?
A) Implement short-lived authentication tokens with expiration
B) Store tokens in plaintext
C) Disable session expiration
D) Use weak encryption
Answer: A) Implement short-lived authentication tokens with expiration
Explanation: Short-lived authentication tokens prevent attackers from reusing stolen tokens for unauthorized access.
104. How can IoT devices ensure authentication credentials are not exposed during transmission?
A) Use end-to-end encryption (TLS/SSL)
B) Send passwords in plaintext
C) Store passwords in firmware
D) Allow authentication over HTTP
Answer: A) Use end-to-end encryption (TLS/SSL)
Explanation: TLS/SSL encryption secures authentication traffic, preventing man-in-the-middle (MITM) attacks.
105. What is a major flaw of using static API keys for IoT authentication?
A) If exposed, they allow permanent unauthorized access
B) They enhance authentication security
C) They improve API response time
D) They prevent credential theft
Answer: A) If exposed, they allow permanent unauthorized access
Explanation: Static API keys can be leaked or stolen, allowing attackers to access IoT APIs indefinitely.
106. Which best practice reduces the risk of unauthorized remote access to IoT devices?
A) Disabling unused remote access services
B) Enabling public authentication endpoints
C) Allowing anonymous logins
D) Using factory default passwords
Answer: A) Disabling unused remote access services
Explanation: Disabling unused or unnecessary remote access services reduces the attack surface of IoT devices.
107. What is the primary reason IoT botnets target devices with weak authentication?
A) To hijack devices for DDoS attacks
B) To improve device performance
C) To help users reset their passwords
D) To enhance device security
Answer: A) To hijack devices for DDoS attacks
Explanation: Attackers compromise IoT devices with weak authentication and add them to botnets for large-scale DDoS attacks (e.g., Mirai botnet).
108. How can IoT manufacturers improve authentication security?
A) Enforcing password complexity rules and multi-factor authentication
B) Hardcoding usernames and passwords
C) Storing passwords in plaintext
D) Using weak API authentication
Answer: A) Enforcing password complexity rules and multi-factor authentication
Explanation: Strong password policies and MFA significantly reduce IoT authentication vulnerabilities.
109. What is a common IoT authentication attack that exploits weak password storage?
A) Credential dumping
B) Cross-site scripting (XSS)
C) ARP spoofing
D) SQL Injection
Answer: A) Credential dumping
Explanation: Credential dumping extracts stored authentication data (e.g., passwords, hashes) from compromised IoT devices.
110. Why is biometric authentication not commonly used in IoT devices?
A) IoT devices often lack the necessary processing power and storage
B) Biometrics are less secure than passwords
C) Biometric authentication increases hacking risks
D) Biometrics require manual password entry
Answer: A) IoT devices often lack the necessary processing power and storage
Explanation: Many low-power IoT devices cannot support biometric authentication due to hardware limitations.
111. What is an effective countermeasure against session hijacking in IoT authentication?
A) Implementing session expiration and token rotation
B) Disabling encryption
C) Allowing static authentication tokens
D) Using plaintext session storage
Answer: A) Implementing session expiration and token rotation
Explanation: Session expiration and frequent token rotation prevent attackers from reusing stolen session tokens.
112. Why should IoT devices use client-side certificates for authentication?
A) To verify trusted devices securely
B) To disable password-based authentication
C) To allow all devices to authenticate anonymously
D) To make IoT networks slower
Answer: A) To verify trusted devices securely
Explanation: Client-side certificates authenticate only trusted devices, preventing unauthorized access.
113. What is a security risk of using SMS-based authentication for IoT devices?
A) SIM swapping attacks can allow attackers to hijack SMS codes
B) SMS-based authentication is faster than password authentication
C) SMS increases IoT battery life
D) SMS prevents replay attacks
Answer: A) SIM swapping attacks can allow attackers to hijack SMS codes
Explanation: Attackers can perform SIM swapping to hijack SMS-based authentication and gain unauthorized access.
114. What type of IoT attack targets poorly secured authentication endpoints?
A) Automated brute-force attacks
B) SQL Injection
C) Clickjacking
D) Memory corruption
Answer: A) Automated brute-force attacks
Explanation: Attackers use automated brute-force tools to guess weak authentication credentials.
115. How can IoT authentication logs help in security?
A) By detecting suspicious login attempts and unauthorized access
B) By slowing down authentication
C) By improving device battery life
D) By preventing encryption
Answer: A) By detecting suspicious login attempts and unauthorized access
Explanation: Log monitoring helps detect failed logins, brute-force attempts, and suspicious activities.
116. What is a Zero Trust authentication approach for IoT devices?
A) Verifying every authentication request, regardless of network location
B) Allowing devices on the same network to authenticate automatically
C) Using static credentials for authentication
D) Storing passwords in plaintext
Answer: A) Verifying every authentication request, regardless of network location
Explanation: Zero Trust authentication requires continuous verification, reducing insider threats.
117. Why should IoT authentication never rely on only security questions?
A) Security questions are easily guessed or leaked
B) Security questions speed up authentication
C) Security questions encrypt passwords
D) Security questions replace MFA
Answer: A) Security questions are easily guessed or leaked
Explanation: Many security questions can be guessed using social engineering or publicly available data.
118. What risk arises if IoT authentication logs are not protected?
A) Attackers can analyze login logs to identify valid credentials
B) Logs improve device encryption
C) Logs reduce authentication risks
D) Logs increase network speed
Answer: A) Attackers can analyze login logs to identify valid credentials
Explanation: If logs are unencrypted or publicly accessible, attackers can extract authentication data.
119. Why should IoT authentication systems enforce password expiration?
A) To reduce the risk of credential reuse attacks
B) To speed up authentication
C) To reduce encryption strength
D) To allow anonymous logins
Answer: A) To reduce the risk of credential reuse attacks
Explanation: Regular password changes help prevent long-term use of compromised credentials.
120. What is a recommended best practice for IoT API authentication?
A) Using OAuth 2.0 token-based authentication
B) Allowing anonymous API access
C) Hardcoding API keys
D) Using static session tokens
Answer: A) Using OAuth 2.0 token-based authentication
Explanation: OAuth 2.0 provides secure token-based authentication, reducing exposure of sensitive credentials.
121. What is the most effective method to prevent unauthorized API access in IoT devices?
A) Implementing API key rotation and OAuth 2.0
B) Using hardcoded API keys
C) Allowing all devices to access APIs without authentication
D) Storing API credentials in plaintext
Answer: A) Implementing API key rotation and OAuth 2.0
Explanation: API key rotation and OAuth 2.0 prevent unauthorized API access by ensuring credentials are not static or exposed.
122. What is a critical risk of using weak passwords in IoT authentication?
A) Attackers can perform brute-force and dictionary attacks
B) Devices run faster
C) Passwords become easier to remember
D) Authentication speed increases
Answer: A) Attackers can perform brute-force and dictionary attacks
Explanation: Weak passwords make it easier for attackers to guess credentials using automated attacks.
123. Why is it dangerous for IoT devices to use default admin credentials?
A) Default credentials are often publicly available or leaked
B) It makes it harder to troubleshoot
C) It reduces the risk of brute-force attacks
D) It speeds up authentication
Answer: A) Default credentials are often publicly available or leaked
Explanation: Default admin credentials can be found in public databases, making them an easy target for attackers.
124. What is an effective countermeasure against replay attacks in IoT authentication?
A) Implementing one-time passwords (OTP) and challenge-response authentication
B) Using static authentication tokens
C) Allowing authentication over unencrypted channels
D) Disabling encryption
Answer: A) Implementing one-time passwords (OTP) and challenge-response authentication
Explanation: OTP and challenge-response mechanisms prevent attackers from reusing old authentication requests.
125. Which type of authentication attack involves stealing session cookies to gain unauthorized access?
A) Session hijacking
B) SQL Injection
C) DNS Spoofing
D) Cross-site scripting (XSS)
Answer: A) Session hijacking
Explanation: Session hijacking occurs when attackers steal authentication session cookies, allowing them to access a device without logging in.
126. Why should IoT devices enforce account lockout policies?
A) To prevent brute-force attacks by limiting login attempts
B) To allow unlimited login attempts
C) To improve authentication speed
D) To disable encryption
Answer: A) To prevent brute-force attacks by limiting login attempts
Explanation: Account lockout policies help prevent brute-force attacks by blocking multiple failed login attempts.
127. What is an effective method for securing IoT device authentication against phishing attacks?
A) Implementing multi-factor authentication (MFA)
B) Using plaintext passwords
C) Allowing users to reuse old passwords
D) Disabling HTTPS
Answer: A) Implementing multi-factor authentication (MFA)
Explanation: MFA adds an extra security layer, making it harder for attackers to gain access using stolen credentials.
128. What is a primary risk of exposing IoT authentication logs without encryption?
A) Attackers can analyze logs to extract credentials
B) Logs increase device processing speed
C) Logs make authentication faster
D) Logs improve encryption
Answer: A) Attackers can analyze logs to extract credentials
Explanation: Unencrypted logs can be used by attackers to find passwords, authentication attempts, and API tokens.
129. Which of the following helps prevent automated brute-force attacks on IoT devices?
A) Implementing CAPTCHA and rate limiting
B) Allowing unlimited login attempts
C) Using default credentials
D) Storing passwords in plaintext
Answer: A) Implementing CAPTCHA and rate limiting
Explanation: CAPTCHA and rate limiting prevent automated bots from attempting multiple password guesses.
130. Why should IoT authentication use token-based authentication instead of session IDs?
A) Tokens can be revoked and refreshed dynamically
B) Tokens make authentication slower
C) Tokens prevent encryption
D) Tokens make brute-force attacks easier
Answer: A) Tokens can be revoked and refreshed dynamically
Explanation: Token-based authentication provides better session security and allows tokens to be revoked if compromised.
131. What is a common vulnerability when IoT authentication is implemented via mobile apps?
A) API keys and credentials hardcoded into mobile apps
B) Passwords stored securely
C) Authentication logs are encrypted
D) MFA is enforced
Answer: A) API keys and credentials hardcoded into mobile apps
Explanation: If an attacker decompiles a mobile app, they can extract hardcoded API keys and access IoT authentication endpoints.
132. What is a common way attackers bypass weak authentication in IoT web interfaces?
A) Exploiting insecure password reset mechanisms
B) Using strong passwords
C) Encrypting all login attempts
D) Enforcing MFA
Answer: A) Exploiting insecure password reset mechanisms
Explanation: Attackers reset weak authentication mechanisms using insecure password recovery features.
133. What attack is commonly performed on IoT authentication systems that allow unlimited login attempts?
A) Credential stuffing
B) Packet sniffing
C) SQL Injection
D) DNS Poisoning
Answer: A) Credential stuffing
Explanation: Credential stuffing uses leaked passwords from other sites to attempt logins on IoT devices.
134. Why is OAuth 2.0 considered more secure for IoT authentication than basic authentication?
A) It eliminates the need for storing passwords on IoT devices
B) It speeds up login attempts
C) It allows anonymous authentication
D) It makes credential theft easier
Answer: A) It eliminates the need for storing passwords on IoT devices
Explanation: OAuth 2.0 uses access tokens, preventing password exposure on IoT devices.
135. What is an effective method for securing authentication in IoT smart home devices?
A) Enabling device-based authentication and MFA
B) Using short, easy-to-guess passwords
C) Allowing anonymous access
D) Storing credentials in plaintext
Answer: A) Enabling device-based authentication and MFA
Explanation: Device-based authentication and MFA ensure only trusted users and devices can authenticate.
136. What happens if an IoT authentication system does not implement session expiration?
A) Attackers can reuse old authentication sessions
B) Users must log in frequently
C) Encryption becomes stronger
D) Authentication speeds up
Answer: A) Attackers can reuse old authentication sessions
Explanation: Without session expiration, attackers can steal and reuse session cookies or tokens indefinitely.
137. Why should IoT authentication avoid using SMS-based verification?
A) SMS messages can be intercepted using SIM-swapping attacks
B) SMS improves security
C) SMS reduces hacking attempts
D) SMS prevents credential theft
Answer: A) SMS messages can be intercepted using SIM-swapping attacks
Explanation: SIM swapping and SS7 attacks allow attackers to hijack SMS-based authentication codes.
138. What is a critical risk of weak authentication in IoT devices used in industrial control systems (ICS)?
A) Attackers can take over and manipulate industrial processes
B) ICS systems use low power
C) ICS devices require no authentication
D) ICS systems prevent hacking by default
Answer: A) Attackers can take over and manipulate industrial processes
Explanation: Weak authentication in ICS devices allows attackers to disrupt or manipulate critical industrial operations.
139. Why should IoT authentication logs be stored in a secure, centralized location?
A) To detect unauthorized access attempts across multiple devices
B) To allow easy password retrieval
C) To improve network speed
D) To reduce encryption strength
Answer: A) To detect unauthorized access attempts across multiple devices
Explanation: Centralized log storage helps in monitoring authentication attempts and detecting anomalous behavior.
140. Which of the following is a security benefit of certificate-based authentication in IoT devices?
A) It verifies device authenticity without using passwords
B) It makes authentication easier for attackers
C) It allows password reuse
D) It prevents encryption
Answer: A) It verifies device authenticity without using passwords
Explanation: Certificate-based authentication provides secure device verification without relying on passwords.
141. What is a critical vulnerability when IoT devices store passwords using weak hashing algorithms?
A) Attackers can crack password hashes using rainbow table attacks
B) Devices run faster
C) It increases password security
D) It prevents brute-force attacks
Answer: A) Attackers can crack password hashes using rainbow table attacks
Explanation: Weak hashing algorithms (e.g., MD5, SHA-1) allow attackers to use precomputed hash tables (rainbow tables) to crack passwords quickly.
142. What attack is possible if IoT authentication credentials are transmitted without encryption?
A) Man-in-the-Middle (MITM) Attack
B) Clickjacking
C) SQL Injection
D) CAPTCHA bypass
Answer: A) Man-in-the-Middle (MITM) Attack
Explanation: MITM attacks allow attackers to intercept plaintext authentication credentials if they are transmitted over an unencrypted connection.
143. What is the role of a Hardware Security Module (HSM) in IoT authentication?
A) Securely stores encryption keys and authentication credentials
B) Increases device speed
C) Stores passwords in plaintext
D) Disables authentication
Answer: A) Securely stores encryption keys and authentication credentials
Explanation: HSMs provide tamper-resistant storage for sensitive authentication data, reducing the risk of credential theft.
144. How does brute-force protection improve IoT authentication security?
A) It limits the number of failed login attempts
B) It allows unlimited password guesses
C) It disables encryption
D) It speeds up login attempts
Answer: A) It limits the number of failed login attempts
Explanation: Brute-force protection prevents attackers from attempting multiple password guesses by limiting retries or implementing CAPTCHA.
145. What is a key benefit of using hardware-based authentication in IoT devices?
A) It prevents credential reuse attacks
B) It allows passwords to be stored in plaintext
C) It disables authentication
D) It reduces encryption strength
Answer: A) It prevents credential reuse attacks
Explanation: Hardware-based authentication (e.g., security keys, TPM chips) ensures each device has a unique, secure authentication mechanism, preventing credential reuse attacks.
146. Which of the following is an insecure practice in IoT authentication?
A) Storing passwords in plaintext
B) Using multi-factor authentication (MFA)
C) Using password hashing algorithms with salt
D) Enforcing password complexity rules
Answer: A) Storing passwords in plaintext
Explanation: Storing plaintext passwords is a serious security flaw, as it allows attackers to access credentials if they compromise the system.
147. Why should IoT devices use role-based access control (RBAC) for authentication?
A) To restrict permissions based on user roles
B) To allow everyone full administrative access
C) To store credentials in plaintext
D) To disable encryption
Answer: A) To restrict permissions based on user roles
Explanation: RBAC ensures that only authorized users can perform certain actions, limiting attackers’ access even if credentials are stolen.
148. What is the primary security risk of IoT devices using default SSH credentials?
A) Attackers can log in remotely using default credentials
B) It improves device performance
C) It enhances authentication security
D) It prevents brute-force attacks
Answer: A) Attackers can log in remotely using default credentials
Explanation: Many IoT devices ship with default SSH credentials, which are publicly known, allowing attackers to gain unauthorized access.
149. What happens if an IoT authentication system does not implement session expiration?
A) Attackers can reuse old authentication sessions
B) Users must log in frequently
C) Encryption becomes stronger
D) Authentication speeds up
Answer: A) Attackers can reuse old authentication sessions
Explanation: Without session expiration, attackers can steal and reuse authentication sessions, leading to unauthorized access.
150. Why should IoT authentication avoid static API keys?
A) Static API keys can be stolen and reused indefinitely
B) They improve security
C) They prevent brute-force attacks
D) They allow faster authentication
Answer: A) Static API keys can be stolen and reused indefinitely
Explanation: Static API keys are a security risk because they do not change, allowing attackers to reuse stolen keys indefinitely.
151. What is a key benefit of using OAuth 2.0 authentication in IoT devices?
A) OAuth 2.0 eliminates the need to store passwords on the device
B) It speeds up authentication
C) It allows anonymous authentication
D) It makes brute-force attacks easier
Answer: A) OAuth 2.0 eliminates the need to store passwords on the device
Explanation: OAuth 2.0 replaces passwords with tokens, reducing the risk of credential exposure.
152. How does device fingerprinting improve IoT authentication?
A) Identifies and authenticates trusted devices
B) Reduces encryption strength
C) Stores passwords in plaintext
D) Allows anonymous authentication
Answer: A) Identifies and authenticates trusted devices
Explanation: Device fingerprinting ensures that only known, trusted devices can authenticate.
153. What is the risk of storing authentication logs in plaintext?
A) Attackers can extract credentials and sensitive login data
B) Logs improve device encryption
C) Logs reduce authentication risks
D) Logs increase network speed
Answer: A) Attackers can extract credentials and sensitive login data
Explanation: Unencrypted logs allow attackers to analyze login patterns, extract API keys, or gain credentials.
154. Why should IoT devices enforce two-factor authentication (2FA)?
A) It provides an additional security layer beyond passwords
B) It allows brute-force attacks
C) It speeds up authentication
D) It removes the need for encryption
Answer: A) It provides an additional security layer beyond passwords
Explanation: 2FA ensures that even if an attacker steals credentials, they cannot access the account without the second authentication factor.
155. What type of attack exploits weak password storage in IoT devices?
A) Hash cracking attacks
B) SQL Injection
C) XSS Attacks
D) Phishing
Answer: A) Hash cracking attacks
Explanation: If IoT devices store weakly hashed passwords, attackers can crack them using hash-cracking tools like Hashcat.
156. Why is rate-limiting important for IoT authentication endpoints?
A) It prevents brute-force and credential stuffing attacks
B) It speeds up authentication
C) It allows unlimited login attempts
D) It stores passwords securely
Answer: A) It prevents brute-force and credential stuffing attacks
Explanation: Rate-limiting restricts repeated authentication attempts, making brute-force and automated attacks more difficult.
157. What is a security risk of using basic authentication (username/password) in IoT devices?
A) Credentials are often sent in unencrypted base64 encoding
B) It enhances authentication security
C) It prevents unauthorized access
D) It makes IoT devices faster
Answer: A) Credentials are often sent in unencrypted base64 encoding
Explanation: Basic authentication sends credentials in base64 format, which can be easily intercepted and decoded if encryption is not used.
158. What security feature prevents session hijacking in IoT authentication?
A) Using secure session cookies with the HttpOnly and Secure flag
B) Disabling encryption
C) Allowing static authentication tokens
D) Storing passwords in plaintext
Answer: A) Using secure session cookies with the HttpOnly and Secure flag
Explanation: HttpOnly and Secure flags prevent session tokens from being accessed by JavaScript or transmitted over unencrypted connections.
161. What is a major weakness of IoT authentication that allows attackers to bypass login security?
A) Lack of account lockout policies
B) Strong password hashing
C) Use of multi-factor authentication (MFA)
D) Using encryption for login credentials
Answer: A) Lack of account lockout policies
Explanation: Without account lockout mechanisms, attackers can continuously attempt brute-force login attempts until they find the correct credentials.
162. Which IoT protocol is commonly vulnerable to authentication-related attacks due to lack of encryption?
A) MQTT
B) HTTPS
C) SSH
D) TLS
Answer: A) MQTT
Explanation: MQTT (Message Queuing Telemetry Transport) is widely used in IoT but is often misconfigured to send authentication credentials in plaintext, making it vulnerable to MITM attacks.
163. Why should IoT devices use secure password storage methods?
A) To prevent offline password cracking attacks
B) To speed up authentication
C) To reduce network congestion
D) To allow default credentials
Answer: A) To prevent offline password cracking attacks
Explanation: Storing passwords using strong hashing algorithms like bcrypt, Argon2, or PBKDF2 makes offline cracking attacks significantly harder.
164. What type of IoT authentication vulnerability arises when firmware updates contain hardcoded credentials?
A) Backdoor access for attackers
B) Improved device security
C) Faster authentication
D) Reduced brute-force attacks
Answer: A) Backdoor access for attackers
Explanation: If hardcoded credentials are included in firmware updates, attackers can extract them and gain unauthorized access to devices.
165. How can IoT devices prevent credential stuffing attacks?
A) Blocking login attempts after repeated failures
B) Using factory default credentials
C) Storing passwords in plaintext
D) Disabling HTTPS
Answer: A) Blocking login attempts after repeated failures
Explanation: Credential stuffing attacks use previously leaked credentials, but implementing rate-limiting and account lockout policies can reduce the risk.
166. What is the best practice for storing API authentication credentials in IoT devices?
A) Using secure hardware-based storage like TPM or HSM
B) Storing them in plaintext files
C) Hardcoding them in firmware
D) Allowing unauthenticated API access
Answer: A) Using secure hardware-based storage like TPM or HSM
Explanation: Hardware Security Modules (HSMs) and Trusted Platform Modules (TPMs) provide secure storage for authentication keys, preventing credential theft.
167. Why is using plaintext credentials in IoT logs a security risk?
A) Attackers can read authentication logs to steal passwords
B) It improves password security
C) It reduces storage space
D) It prevents brute-force attacks
Answer: A) Attackers can read authentication logs to steal passwords
Explanation: If authentication logs store passwords in plaintext, attackers who gain access to logs can easily extract credentials.
168. What is a risk of using the same password across multiple IoT devices?
A) If one device is compromised, all devices become vulnerable
B) It strengthens authentication
C) It prevents credential stuffing
D) It speeds up authentication
Answer: A) If one device is compromised, all devices become vulnerable
Explanation: Reusing passwords across multiple IoT devices allows attackers to breach multiple devices with a single set of stolen credentials.
169. How can IoT devices prevent man-in-the-middle (MITM) attacks on authentication?
A) Using encrypted communication protocols like TLS/SSL
B) Sending passwords in plaintext
C) Allowing unauthenticated remote access
D) Using weak encryption algorithms
Answer: A) Using encrypted communication protocols like TLS/SSL
Explanation: TLS/SSL encryption prevents attackers from intercepting authentication traffic, reducing MITM risks.
170. Why should IoT authentication APIs use OAuth or JWT-based authentication?
A) To prevent credential exposure and session hijacking
B) To improve login speed
C) To allow anonymous authentication
D) To remove encryption requirements
Answer: A) To prevent credential exposure and session hijacking
Explanation: OAuth and JWT tokens prevent password exposure, making authentication more secure.
171. Why should IoT authentication mechanisms avoid predictable password reset questions?
A) Attackers can guess or obtain answers via social engineering
B) It speeds up authentication
C) It prevents MITM attacks
D) It improves encryption
Answer: A) Attackers can guess or obtain answers via social engineering
Explanation: Security questions like “What is your pet’s name?” can be easily guessed using public or social media data.
172. What is a recommended way to secure IoT authentication tokens?
A) Storing them securely using encryption and expiring them after a short period
B) Allowing unlimited token reuse
C) Using static session tokens
D) Storing them in plaintext logs
Answer: A) Storing them securely using encryption and expiring them after a short period
Explanation: Secure token storage and expiration policies prevent attackers from hijacking authentication tokens.
173. Why is device whitelisting an effective IoT authentication security measure?
A) Only pre-approved devices can authenticate
B) It weakens authentication
C) It makes passwords unnecessary
D) It prevents encryption
Answer: A) Only pre-approved devices can authenticate
Explanation: Whitelisting restricts authentication access to trusted devices, reducing unauthorized access risks.
174. What is a security risk of IoT authentication APIs using weak CORS policies?
A) Attackers can exploit API authentication via cross-origin requests
B) It prevents brute-force attacks
C) It improves encryption strength
D) It speeds up authentication
Answer: A) Attackers can exploit API authentication via cross-origin requests
Explanation: Poorly configured CORS policies allow unauthorized third-party sites to interact with authentication APIs.
175. What is an effective way to prevent IoT session hijacking?
A) Using secure, short-lived session tokens with HTTPS
B) Allowing long-lived authentication sessions
C) Disabling authentication
D) Storing session tokens in URL parameters
Answer: A) Using secure, short-lived session tokens with HTTPS
Explanation: Short-lived, secure session tokens prevent attackers from stealing and reusing session credentials.
176. What is a common mistake when implementing multi-factor authentication (MFA) in IoT devices?
A) Using SMS-based authentication, which can be intercepted
B) Using biometric authentication
C) Implementing hardware-based security keys
D) Enforcing time-based OTP authentication
Answer: A) Using SMS-based authentication, which can be intercepted
Explanation: SMS-based authentication is vulnerable to SIM swapping attacks, making it an insecure MFA option.
177. How does fuzzing help test IoT authentication security?
A) It sends unexpected or malformed authentication data to find weaknesses
B) It encrypts login attempts
C) It improves device performance
D) It prevents DDoS attacks
Answer: A) It sends unexpected or malformed authentication data to find weaknesses
Explanation: Fuzzing helps detect authentication vulnerabilities by sending randomized or unexpected inputs.
178. What is a primary weakness of using biometric authentication in IoT devices?
A) Biometric data, once stolen, cannot be changed
B) It speeds up authentication
C) It requires less storage
D) It improves battery life
Answer: A) Biometric data, once stolen, cannot be changed
Explanation: Unlike passwords, biometric data is permanent, meaning if it is compromised, it cannot be reset like a password.
179. Why should IoT devices implement certificate-based authentication instead of passwords?
A) Certificates provide strong, unique authentication without requiring passwords
B) Certificates are easier to share publicly
C) Certificates make devices run faster
D) Certificates store credentials in plaintext
Answer: A) Certificates provide strong, unique authentication without requiring passwords
Explanation: Certificate-based authentication allows devices to authenticate securely without using shared credentials.
180. What is the risk of allowing unauthenticated firmware updates on IoT devices?
A) Attackers can install malicious firmware (firmware tampering attacks)
B) The device operates faster
C) Authentication becomes more secure
D) The device uses less power
Answer: A) Attackers can install malicious firmware (firmware tampering attacks)
Explanation: If firmware updates are not authenticated, attackers can install malicious firmware, leading to device compromise.
181. Why is device ID-based authentication not always secure for IoT devices?
A) Device IDs can be spoofed or cloned
B) Device IDs require complex passwords
C) Device IDs improve encryption
D) Device IDs eliminate all authentication risks
Answer: A) Device IDs can be spoofed or cloned
Explanation: Attackers can clone or spoof device IDs to bypass authentication and gain unauthorized access.
182. What is a common mistake when implementing IoT authentication via mobile apps?
A) Hardcoding API keys and credentials inside the mobile app
B) Encrypting all login attempts
C) Using multi-factor authentication (MFA)
D) Implementing hardware-based authentication
Answer: A) Hardcoding API keys and credentials inside the mobile app
Explanation: If an attacker decompiles the mobile app, they can extract hardcoded API keys, leading to security breaches.
183. What is a critical weakness of one-time passwords (OTP) sent via email or SMS?
A) They can be intercepted using phishing or SIM-swapping attacks
B) They increase encryption strength
C) They improve IoT device speed
D) They prevent all brute-force attacks
Answer: A) They can be intercepted using phishing or SIM-swapping attacks
Explanation: Attackers can phish OTPs via fake login pages or hijack SMS-based authentication via SIM-swapping attacks.
184. What attack can compromise IoT authentication tokens if they are stored in browser local storage?
A) Cross-Site Scripting (XSS) attacks
B) Phishing
C) Denial of Service (DoS)
D) SQL Injection
Answer: A) Cross-Site Scripting (XSS) attacks
Explanation: If authentication tokens are stored in local storage, attackers can steal them using XSS attacks, leading to session hijacking.
185. Why is mutual authentication important for IoT security?
A) Both the client and server verify each other’s identity
B) It slows down authentication
C) It reduces encryption strength
D) It prevents firmware updates
Answer: A) Both the client and server verify each other’s identity
Explanation: Mutual authentication ensures that both the IoT device and the server confirm each other’s legitimacy, preventing man-in-the-middle attacks.
186. What is an effective method for preventing token theft in IoT authentication?
A) Using short-lived tokens with frequent renewal
B) Storing authentication tokens in plaintext
C) Allowing unlimited reuse of authentication tokens
D) Using static session tokens
Answer: A) Using short-lived tokens with frequent renewal
Explanation: Short-lived tokens reduce the risk of attackers hijacking and reusing authentication tokens.
187. What is a risk of allowing authentication over unencrypted Bluetooth connections in IoT devices?
A) Attackers can eavesdrop and steal credentials using Bluetooth sniffing
B) It speeds up authentication
C) It prevents brute-force attacks
D) It improves encryption strength
Answer: A) Attackers can eavesdrop and steal credentials using Bluetooth sniffing
Explanation: Unencrypted Bluetooth authentication can be intercepted by attackers using sniffing tools like Ubertooth.
188. What is the impact of weak password policies on IoT device security?
A) Devices become vulnerable to brute-force and dictionary attacks
B) Authentication becomes stronger
C) Devices consume less power
D) Encryption strength increases
Answer: A) Devices become vulnerable to brute-force and dictionary attacks
Explanation: Weak password policies (e.g., allowing short passwords) make brute-force attacks easier, leading to unauthorized access.
189. What is an advantage of using public key authentication in IoT devices?
A) It eliminates the need for password-based authentication
B) It weakens encryption
C) It allows anonymous authentication
D) It speeds up login attempts
Answer: A) It eliminates the need for password-based authentication
Explanation: Public key authentication (e.g., SSH keys) provides a more secure alternative to passwords, reducing credential theft risks.
190. Why should IoT authentication logs be monitored in real-time?
A) To detect and respond to unauthorized login attempts quickly
B) To slow down authentication
C) To reduce device performance
D) To store passwords
Answer: A) To detect and respond to unauthorized login attempts quickly
Explanation: Real-time monitoring helps identify failed login attempts, brute-force attacks, and suspicious access patterns before a security breach occurs.
191. What is a key risk of using long-lived authentication tokens in IoT devices?
A) If stolen, they can be used for extended unauthorized access
B) They improve security
C) They reduce encryption strength
D) They prevent brute-force attacks
Answer: A) If stolen, they can be used for extended unauthorized access
Explanation: Long-lived authentication tokens increase the risk of session hijacking and unauthorized access if stolen, as they remain valid for long periods.
192. How can IoT devices prevent brute-force attacks on authentication endpoints?
A) Implementing account lockouts and CAPTCHA mechanisms
B) Allowing unlimited login attempts
C) Using plaintext password storage
D) Storing passwords in logs
Answer: A) Implementing account lockouts and CAPTCHA mechanisms
Explanation: Account lockout policies and CAPTCHA challenges help prevent automated brute-force attacks by limiting repeated authentication attempts.
193. What is the role of cryptographic salts in IoT password security?
A) They prevent the use of precomputed hash attacks (rainbow tables)
B) They slow down authentication
C) They store passwords in plaintext
D) They replace password hashing
Answer: A) They prevent the use of precomputed hash attacks (rainbow tables)
Explanation: Salting passwords before hashing ensures each password hash is unique, making rainbow table attacks ineffective.
194. What type of attack targets IoT authentication by capturing and reusing valid authentication requests?
A) Replay attack
B) SQL Injection
C) Clickjacking
D) Phishing
Answer: A) Replay attack
Explanation: Replay attacks occur when attackers capture authentication requests and resend them later to gain unauthorized access.
195. Why should IoT authentication APIs implement rate-limiting?
A) To prevent automated brute-force and credential stuffing attacks
B) To store passwords securely
C) To remove encryption requirements
D) To allow anonymous authentication
Answer: A) To prevent automated brute-force and credential stuffing attacks
Explanation: Rate-limiting prevents attackers from making rapid repeated login attempts, reducing brute-force attack success rates.
196. What is an effective way to prevent phishing-based credential theft in IoT authentication?
A) Using FIDO2 or passwordless authentication methods
B) Storing passwords in plaintext
C) Allowing unlimited login attempts
D) Disabling encryption
Answer: A) Using FIDO2 or passwordless authentication methods
Explanation: FIDO2 and passwordless authentication reduce the risk of credential theft because there is no password for attackers to steal via phishing.
197. Why should IoT authentication mechanisms avoid using SMS-based verification codes?
A) They can be intercepted through SIM-swapping and SS7 attacks
B) They improve security
C) They increase encryption strength
D) They reduce brute-force attacks
Answer: A) They can be intercepted through SIM-swapping and SS7 attacks
Explanation: SMS-based authentication codes can be intercepted or redirected by attackers using SIM-swapping and SS7 vulnerabilities.
198. How does using OAuth 2.0 for API authentication improve IoT security?
A) It eliminates the need for storing passwords in IoT devices
B) It speeds up authentication
C) It allows all devices to authenticate anonymously
D) It replaces encryption with API keys
Answer: A) It eliminates the need for storing passwords in IoT devices
Explanation: OAuth 2.0 replaces password authentication with token-based authentication, reducing the risk of password exposure.
199. What risk arises when IoT authentication relies solely on MAC address filtering?
A) Attackers can spoof MAC addresses to bypass authentication
B) MAC filtering speeds up authentication
C) It prevents brute-force attacks
D) It improves encryption
Answer: A) Attackers can spoof MAC addresses to bypass authentication
Explanation: MAC addresses can be easily spoofed, allowing attackers to bypass authentication mechanisms based on MAC filtering.
200. Why should IoT authentication not rely solely on user-generated passwords?
A) Users often choose weak, easily guessable passwords
B) It makes brute-force attacks harder
C) It increases authentication speed
D) It improves encryption
Answer: A) Users often choose weak, easily guessable passwords
Explanation: Many users select weak passwords, making them susceptible to brute-force and dictionary attacks.
201. What is a security advantage of using client certificates for IoT authentication?
A) They authenticate devices without requiring passwords
B) They allow easy credential reuse
C) They weaken encryption
D) They prevent device authentication
Answer: A) They authenticate devices without requiring passwords
Explanation: Client certificates securely verify devices, removing the need for password-based authentication.
202. What attack can occur if IoT authentication tokens are stored in browser cookies without the HttpOnly flag?
A) Cross-Site Scripting (XSS) attack
B) SQL Injection
C) Brute-force attack
D) Phishing
Answer: A) Cross-Site Scripting (XSS) attack
Explanation: If authentication tokens are stored in cookies without the HttpOnly flag, attackers can steal them via XSS attacks.
203. Why should IoT authentication use short-lived session tokens?
A) To limit the damage if a token is compromised
B) To prevent encryption
C) To allow long-term authentication
D) To store credentials in plaintext
Answer: A) To limit the damage if a token is compromised
Explanation: Short-lived tokens expire quickly, reducing the risk of session hijacking if stolen.
204. How does multi-factor authentication (MFA) enhance IoT security?
A) It requires an additional authentication factor beyond passwords
B) It weakens password security
C) It replaces encryption
D) It prevents all cyberattacks
Answer: A) It requires an additional authentication factor beyond passwords
Explanation: MFA requires an additional verification method, such as a one-time code, biometric, or security key, making compromised passwords less effective for attackers.
205. What is the benefit of using hardware security keys (e.g., YubiKey) for IoT authentication?
A) They provide phishing-resistant, passwordless authentication
B) They weaken authentication
C) They make brute-force attacks easier
D) They reduce encryption
Answer: A) They provide phishing-resistant, passwordless authentication
Explanation: Hardware security keys use public-key cryptography, making them immune to phishing attacks and password leaks.