To confirm integrity for a hashed message, the receiver should use the same hashing algorithm as the sender' s to create a binary image of the file. A hashing algorithm is a mathematical function that transforms an input data into a fixed-length output value, called a hash or a digest. A hashing algorithm has two main properties:
it is one-way, meaning that it is easy to compute the hash from the input, but hard to recover the input from the hash; and it is collision-resistant, meaning that it is very unlikely to find two different inputs that produce the same hash. These properties make hashing algorithms useful for verifying the integrity of data, as any change in the input data will result in a different hash value. Therefore, to confirm integrity for a hashed message, the receiver should use the same hashing algorithm as the sender's to create a binary image of the file, which is a representation of the file in bits (0s and 1s). The receiver should then compare this binary image with the hash value sent by the sender. If they match, then the message has not been altered in transit.
If they do not match, then the message has been corrupted or tampered with.
References:
Ensuring Data Integrity with Hash Codes
Message Integrity

When reviewing a data classification scheme, it is most important for an IS auditor to determine if the security criteria are clearly documented for each classification. This will help the IS auditor to evaluate if the data classification scheme is consistent, comprehensive, and aligned with the organizational objectives and regulatory requirements. The security criteria should define the level of confidentiality, integrity, and availability for each data classification, aswell as the corresponding controls such as access control, rights management, and cryptographic protection1. The other options are less important or incorrect because:
* A. Each information asset is not necessarily assigned to a different classification. Data classification schemesusually have a limited number of categories, such as "Sensitive," "Confidential," and "Public," and multiple information assets can belong to the same category2.
* C. Senior IT managers are not necessarily identified as information owners. Information owners are typically the business units or functions that create, use, or maintain the information assets, and they may or may not be senior IT managers3.
* D. The information owner is not required to approve access to the asset. The information owner is responsible for defining the access requirements and rules for the asset, but the actual approval of access requests may be delegated to other roles, such as data custodians or administrators3. References: Simplify and Contextualize Your Data Classification Efforts - ISACA, 3.7: Establish and Maintain a Data Classification Scheme, Data Classification and Practices - NIST, CISA Exam Content Outline |CISA Certification | ISACA

The audit procedure that would have most likely identified the exception of critical servers not included in the central log repository is to compare a list of all servers from the directory server against a list of all servers present in the central log repository. This would allow the IS auditor to detect any discrepancies or omissions in the central log repository. The other audit procedures (A, C and D) would not be effective in identifying this exception, as they would only focus on the alerts generated, the alert settings configured, or the servers included in the previous year's audit, which may not reflect the current state of the central log repository. References: IS Audit and Assurance Guideline 2202: Evidence Collection Techniques, CISA Review Manual (Digital Version), Chapter 5: Protection of Information Assets, Section 5.3: Logging and Monitoring

Periodic review of access profiles by management is an additional control that is required when using swipe cards to limit employee access to restricted areas. Swipe cards are a type of physical access control that use magnetic stripes or radio frequency identification (RFID) to store and transmit information about the cardholder's identity and access rights. Swipe cards can help to prevent unauthorized entry, protect sensitive assets and data, and monitor access activity. However, swipe cards alone are not enough to ensure effective access control. They need to be complemented by other controls, such as:
Periodic review of access profiles by management: This is a type of logical access control that involves verifying that the access rights assigned to each cardholder are appropriate, necessary, and consistent with the organization's policies and procedures. Periodic review of access profiles can help to detect and correct any errors, inconsistencies, or violations in the access control system, such as outdated, excessive, or redundant access rights, segregation of duties conflicts, or unauthorized changes. Periodic review of access profiles can also help to ensure compliance with internal and external audit requirements and regulations.
Implementation of additional PIN pads: This is a type of multi-factor authentication (MFA) that requires the cardholder to enter a personal identification number (PIN) in addition to swiping their card. MFA can enhance the security of the access control system by adding another layer of verification and reducing the risk of lost, stolen, or cloned cards being used by unauthorized persons.
Installation of closed-circuit television (CCTV): This is a type of surveillance system that uses cameras and monitors to record and display the images of the people and activities in the restricted areas. CCTV can deter potential intruders, provide evidence of any security incidents or breaches, and enable real-time monitoring and response by security personnel.
The other options are not as effective or relevant as periodic review of access profiles by management for an additional control when using swipe cards. Physical sign-in of all employees for access to restricted areas is a redundant and inefficient control that can be easily bypassed or manipulated. It also does not provide any assurance or verification of the identity or access rights of the cardholders. Audit hooks are software routines embedded in an application that can trigger an alert or a report when certain conditions are met. Audit hooks can help to detect anomalies or exceptions in access control lists, but they do not provide a comprehensive or integrated view of them.
References:
ISACA, CISA Review Manual, 27th Edition, 2019, p. 236
ISACA, ITAF: A Professional Practices Framework for IS Audit/Assurance, 3rd Edition, 2014, p. 88 Data Analytics for Auditing Access Control