Isaca Certification CISA Book

 The best method to safeguard data on an organization’s laptop computers is full disk encryption. Full disk encryption is a technique that encrypts all the data stored on a hard drive, including the operating system, applications, files, and folders. This means that if the laptop is lost, stolen, or accessed by an unauthorized person, they will not be able to read or modify any data without knowing the encryption key or password. Full disk encryption provides a strong level of protection for data at rest, as it prevents data leakage or exposure in case of physical theft or loss of the device.

References:

How to Protect the Data on Your Laptop

6 Steps to Practice Strong Laptop Security

Application level firewalls are the best control to prevent the transfer of files to external parties through instant messaging (IM) applications, because they can inspect and filter network traffic based on application-specific protocols and commands, such as IM file transfer commands. Application level firewalls can block or allow IM file transfers based on predefined rules or policies. File level encryption, file transfer protocol (FTP), and instant messaging policy are not effective controls to prevent IM file transfers, because they do not restrict or monitor IM network traffic. References: CISA Review Manual (Digital Version), Chapter 5, Section 5.4.1

Reviewing input and output control reports to verify the accuracy of the system decisions is the most important procedure for the IS auditor to perform during the post-implementation review of intelligent-agent software for granting loans to customers, because it can help identify any errors or anomalies in the system logic or data that may affect the quality and reliability of the system outcomes. Reviewing system and error logs, signed approvals, and system documentation are also important procedures, but they are not as critical as verifying the accuracy of the system decisions. References: CISA Review Manual (Digital Version), Chapter 4, Section 4.2.21

 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