CertMaster Learn Lessons Flashcards
_______ is a means of redirecting users from a legitimate website to a malicious one that relies on corrupting the way the victim’s computer performs IP address resolution. This is illustrated in the bank customer scenario.
Pharming
__________ can make a phishing or hoax email more convincing. Used offensively, ______ means adding text that appears to have been generated by the mail system.
Prepending
How does an encryption algorithm protect against birthday attacks?
Encryption algorithms add salt when computing password hashes
A salt is an additional value stored with the hashed data field. The purpose of salt is to frustrate attempts to crack the hashes of passwords by dramatically decreasing the probability of collision. This will protect against birthday attacks.
__________ obscures the presence of a message and can be used to encode messages within TCP packet data fields to create a covert message channel for data exfiltration.
Steganography
Which two cryptographic functions can be combined to authenticate a sender and prove the integrity of a message?
Public key cryptography and hashing
Public key cryptography (public and private keys) can be used to authenticate a sender. Combine this with a hash output of the message and a secret (or private) key to create a message authentication code (MAC) to validate the integrity of the message.
_________ mitigates the risks from RSA key exchanges through the use of ephemeral session keys to maintain confidentiality.
Perfect forward security (PFS)
Compare and contrast the modes of operation for block ciphers. Which of the following statements is true?
ECB and CBC modes allow block ciphers to behave like stream ciphers.
CTM mode allows block ciphers to behave like stream ciphers.
ECB allows block ciphers to behave like stream ciphers.
CBC and CTM modes allow block ciphers to behave like stream ciphers.
CTM mode allows block ciphers to behave like stream ciphers.
Explanation - Counter Mode (CTM) combines each block with a counter value, allowing each block to be processed individually and in parallel, improving performance. This parallel processing is similar to how stream ciphers operate.
Tags - Lesson 5
A _____ is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, _____ are often used to verify data integrity but are not relied upon to verify data authenticity
Checksums
Digital certificates are based on the X.509 standard that defines the fields (or information) about a subject (or entity using the certificate) and the certificate’s issuer. Which of the following fields would not be included in a standard public certificate?
Extensions
Public key
Endorsement key
Subject
Endorsement Key
Explanation - An endorsement key is not required for a digital certificate. It is part of a Trusted Platform Module (TPM) and used to create subkeys for key storage, signature, and encryption operations.
An employee has requested a digital certificate for a user to access the Virtual Private Network (VPN). It is discovered that the certificate is also being used for digitally signing emails. Evaluate the possible extension attributes to determine which should be modified so that the certificate only works for VPN access.
Valid from/to
Extended key usage
Serial number
Public key
Extended key usage
Explanation - Set the Extended Key Usage (EKU) field of a certificate to define its usage. Applications such as virtual private network (VPN) or email clients may require specific requirements for key usage configuration.
A company has a critical encryption key that has an M-of-N control configuration for protection. Examine the examples and select the one that correctly illustrates the proper configuration for this type of protection of critical encryption keys.
M=1 and N=5
M=3 and N=5
M=6 and N=5
M=0 and N=5
M=3 and N=5
Explanation - A correct configuration for an M-of-N control is M=3 and N=5. M stands for the number of authorized administrators that must be present to access the critical encryption keys and N is the total number of authorized administrators. In this scenario, 3 of the 5 administrators must be present for access.
Consider the life cycle of an encryption key. Which of the following is NOT a stage in a key’s life cycle?
Storage
Verification
Expiration and renewal
Revocation
Verification
Explanation - Verification is not a stage in a key’s life cycle. It is part of the software development life cycle. The stages are: key generation, certificate generation, storage, revocation, and expiration and renewal.
A website with many subdomains has been issued a web server certificate for domain validation. This certificate verifies the parent domain and all subdomains (to a single level). This certificate is also known as which of the following?
SAN certificate
Wildcard certificate
Root certificate
Code signing certificate
Wildcard certificate
Explanation - A wildcard certificate with a field entry of a wildcard domain such as *.comptia.org, means that the certificate issued to the parent domain will be accepted as valid for all subdomains (to a single level).
A Certificate Revocation List (CRL) has a publish period set to 24 hours. Based on the normal procedures for a CRL, what is the most applicable validity period for this certificate?
26 hours
Explanation - One or two hours over the publish period is considered normal thus making 26 hours within the window.
Both Remote Access Dial-In User Service (RADIUS) and Terminal Access Controller Access-Control System (TACACS+) provide authentication, authorization, and accounting using a separate server (the AAA server). Based on the protocols’ authentication processes, select the true statements. (Select the best three choices.)
TACACS+ is open source and RADIUS is a proprietary protocol from Cisco.
RADIUS uses UDP by default and TACACS+ uses TCP.
TACACS+ encrypts the whole packet (except the header) and RADIUS only encrypts the password.
RADIUS is primarily used for network access and TACACS+ is primarily used for device administration.
RADIUS uses UDP by default and TACACS+ uses TCP.
TACACS+ encrypts the whole packet (except the header) and RADIUS only encrypts the password.
RADIUS is primarily used for network access and TACACS+ is primarily used for device administration.
**Explanation - **
RADIUS uses UDP by default over ports 1812 and 1813 and TACACS+ uses TCP on port 49.
TACACS+ encrypts the whole packet (except the header, which identifies the packet as TACACS+ data) and RADIUS only encrypts the password portion of the packet using MD5.
RADIUS is primarily used for network access for a remote user and TACACS+ is primarily used for device administration. TACACS+ provides centralized control for administrators to manage routers, switches, and firewall appliances, as well as user privileges.
P.S - RADIUS is open source and TACACS + is Cisco
Based on knowledge of the fundamentals of One-time Passwords (OTP), which of the following choices represents the problem that exists with HMAC-based One-time Password Algorithm (HOTP) and is addressed by Time-based One-time Password Algorithm (TOTP)?
HOTP is not configured with a shared secret.
The server is not configured with a counter in HOTP.
Only the HOTP server computes the hash.
Tokens can be allowed to continue without expiring in HOTP.
Tokens can be allowed to continue without expiring in HOTP.
**Explanation **- Tokens can persist unexpired in HOTP, increasing the risk of an attacker obtaining one and decrypting data in the future. TOTP addresses this by adding a value to the shared secret derived from the device’s and server’s local timestamp. TOTP automatically expires each token after a short window of time.
Regarding the various tools of biometric authentication and their capabilities/limitations, which statement is accurate?
Retinal scanning is less intrusive than iris scanning.
Fingerprint scanners are the most widely used biometric authentication method.
Fingerprint scanners are more expensive but use a straightforward process.
Sensor modules are the most preferred biometric authentication method.
Fingerprint scanners are the most widely used biometric authentication method.
Explanation - Regarding biometric authentication, Fingerprint scanning is the most widely implemented biometric authentication method.
Evaluate how identification and authentication are distinct in their functions. Which of the following scenarios best illustrates a user being authenticated?
A user accesses a system by having their face scanned.
A system administrator sets up a user account for a new employee after HR sends employment verification.
An administrator sends an initial password to a new telecommuting employee through a VPN.
A user is assigned an SID.
A user accesses a system by having their face scanned.
**Explanation **- A face scan is also known as biometrics, which is a “something you are” authentication. This is known as physiological biometric recognition.
Consider biometric methods that are used to authenticate a user. Knowing that errors are possible, which of the following would most likely result in a security breach?
False acceptance
False rejection
A low Crossover-Error-Rate (CER)
A low throughput
False acceptance
Explanation - Regarding biometric authentication, a false positive is where an unauthorized person is accepted, leading to possible security breaches. This is the False Acceptance Rate (FAR).
A user presents a smart card to gain access to a building. Authentication is handled through integration to a Windows server that’s acting as a certificate authority on the network. Review the security processes and conclude which are valid when using Kerberos authentication. (Select all that apply.)
Inputting a correct PIN authorizes the smart card’s cryptoprocessor to use its private key to create a Ticket Granting Ticket (TGT) request.
The smart card generates a one-time use Ticket Granting Service (TGS) session key and certificate.
The Authentication Server (AS) trusts the user’s certificate as it was issued by a local certification authority.
The Authentication Server (AS) is able to decrypt the request because it has a matching certificate.
Inputting a correct PIN authorizes the smart card’s cryptoprocessor to use its private key to create a Ticket Granting Ticket (TGT) request.
The Authentication Server (AS) trusts the user’s certificate as it was issued by a local certification authority.
Explanation -
Inputting a correct PIN authorizes the smart card’s cryptoprocessor to use its private key to create a Ticket Granting Ticket (TGT) request to an Authentication Server (AS).
The AS can place trust when the user’s certificate is issued by a local or third-party root certification authority.
Biometric authentication methods have different error rates, with some methods being easier to fool than others. An unauthorized user is unlikely to fool which of the following methods?
Fingerprint scan
Retinal scan
Facial recognition
Voice recognition
Retinal scan
Explanation - Biometric authentication based on a retinal scan is the hardest method to fool. Retinal scanning is used to identify the patterns of blood vessels with the eye, whereas an iris scan only uses the surface of the eye.
Analyze each scenario and determine which best describes the authentication process in an Identity and Access Management (IAM) system.
An account is created that identifies a user on the network.
A user logs into a system using a control access card (CAC) and PIN number.
An Access Control List (ACL) is updated to allow a new user access to only the databases that are required to perform their job.
A report is reviewed that shows every successful and unsuccessful login attempt on a server.
A user logs into a system using a control access card (CAC) and PIN number.
Explanation - Authentication proves that a subject is who or what it claims to be when it attempts to access the resource. A CAC and pin login are examples of authentication.
Evaluate the following controls that have been set by a system administrator for an online retailer. Determine which statement demonstrates the identification control within the Identity and Access Management (IAM) system.
A control is set to force a customer to log into their account prior to reviewing and editing orders.
A control is set to cancel automatic shipments for any customer that has an expired credit card on file.
A control is set to ensure that billing and primary delivery addresses are valid.
A control is set to record the date, time, IP address, customer account number, and order details for each order.
A control is set to ensure that billing and primary delivery addresses are valid
Explanation - Identification controls are set to ensure that customers are legitimate. An example is to ensure that billing and primary delivery addresses are real and valid.
An Identity and Access Management (IAM) system has four main processes. Which of the following is NOT one of the main processes?
Accounting
Identification
Integrity
Authentication
Integrity
Explanation - Integrity is the fundamental security goal of keeping organizational information accurate, free of errors, and without unauthorized modifications. However, it is not part of the IAM system. IAM defines the attributes that comprise an entity’s identity. The four processes include Authorization, Accounting, Identification, and Authentication.