CompTIA Updated CAS-004 Exam Questions and Answers by khalid

Field masking is a technique that hides or obscures part of the information in a data field, such as a password, credit card number, or social security number. Field masking can be used to protect sensitive or confidential data from unauthorized access or disclosure, while still allowing authorized users to view or verify the data.

Field masking should be implemented to authenticate employees who call in remotely by allowing the help desk staff to view partial information about employees, because field masking would:

Enable the help desk staff to verify the identity of the employees by asking them to provide some characters or digits from their data fields, such as their employee ID or email address.

Prevent the help desk staff from viewing the full information about employees, which may be considered sensitive and subject to privacy regulations or policies.

Reduce the risk of data leakage, theft, or misuse by limiting the exposure of sensitive data to only those who need it.

Public keys on both endpoints are required for implementing PKI-based mutual authentication. PKI stands for Public Key Infrastructure, which is a system that manages the creation, distribution, and verification of certificates. Certificates are digital documents that contain public keys and identity information of their owners. Certificates are issued by trusted authorities called Certificate Authorities (CAs), and can be used to prove the identity and authenticity of the certificate holders. Mutual authentication is a process in which two parties authenticate each other at the same time using certificates. Mutual authentication can provide stronger security and privacy than one-way authentication, where only one party is authenticated. In PKI-based mutual authentication, each party has a certificate that contains its public key and identity information, and a private key that corresponds to its public key. The private key is kept secret and nevershared with anyone, while the public key is shared and used to verify the identity and signature of the certificate holder. The basic steps of PKI-based mutual authentication are as follows:

Party A sends its certificate to Party B.

Party B verifies Party A’s certificate by checking its validity, signature, and trust chain. If the certificate is valid and trusted, Party B extracts Party A’s public key from the certificate.

Party B generates a random challenge (such as a nonce or a timestamp) and encrypts it with Party A’s public key. Party B sends the encrypted challenge to Party A.

Party A decrypts the challenge with its private key and sends it back to Party B.

Party B compares the received challenge with the original one. If they match, Party B confirms that Party A is the legitimate owner of the certificate and has possession of the private key.

The same steps are repeated in reverse, with Party A verifying Party B’s certificate and sending a challenge encrypted with Party B’s public key.

A. Perfect forward secrecy on both endpoints is not required for implementing PKI-based mutual authentication. Perfect forward secrecy (PFS) is a property of encryption protocols that ensures that the compromise of a long-term secret key (such as a private key) does not affect the security of past or future session keys (such as symmetric keys). PFS can enhance the security and privacy of encrypted communications, but it does not provide authentication by itself.

B. Shared secret for both endpoints is not required for implementing PKI-based mutual authentication. Shared secret is a method of authentication that relies on a pre-shared piece of information (such as a password or a passphrase) that is known only to both parties. Shared secret can provide simple and fast authentication, but it does not provide non-repudiation or identity verification.

D. A common public key on each endpoint is not required for implementing PKI-based mutual authentication. A common public key on each endpoint would imply that both parties share the same certificate and private key, which would defeat the purpose of PKI-based mutual authentication. Each party should have its own unique certificate and private key that proves its identity and authenticity.

E. A common private key on each endpoint is not required for implementing PKI-based mutual authentication. A common private key on each endpoint would imply that both parties share the same certificate and public key, which would defeat the purpose of PKI-based mutual authentication. Each party should have its own unique certificate and private key that proves its identity and authenticity.

An immutable system is a system that does not change after it is deployed. Any changes or updates are done by creating a new system from a common image or template and replacing the old one. An immutable system meets the requirements of storing data outside of the VMs, preventing unauthorized modifications to the VMs, and deploying a new VM if a change needs to be done. An immutable system can improve the security, reliability, and consistency of the VMs by avoiding configuration drift, human errors, or malicious tampering. An immutable system can also simplify the deployment process and enable faster recovery from failures. Verified References:

https://cloudinfrastructureservices.co.uk/vm-types-for-devops-pets-vs-cattle-vs-immutable/

https://www.digitalocean.com/community/tutorials/what-is-immutable-infrastructure

Rules of engagement are legal documents that should be signed by all parties involved in an assessment to ensure they understand their roles and responsibilities. Rules of engagement define the scope, objectives, methods, deliverables, limitations, and expectations of an assessment project. They also specify the legal and ethical boundaries, communication channels, escalation procedures, and reporting formats for the assessment. Rules of engagement help to avoid misunderstandings, conflicts, or liabilities during or after an assessment.