Assess Interface And Data Transfer Controls
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CPA Information Systems and Controls (ISC) › Assess Interface And Data Transfer Controls
A company transfers daily sales data from its point-of-sale system to its general ledger. Which of the following controls would best detect if records were lost during the transfer?
Requiring a supervisor to review all sales transactions before transfer.
Encrypting the sales data file during transmission.
Restricting access to the general ledger to accounting staff only.
Comparing record counts and total amounts in the source file to the records loaded into the general ledger after each transfer.
Explanation
Record count and control total reconciliation between source and target systems directly detects data loss during transfer. Answer B is correct. Supervisor review (A) is a manual authorization control. Encryption (C) protects confidentiality. Access restrictions (D) address authorization, not completeness.
An automated interface between a payroll system and a bank's ACH payment system fails silently - transactions are dropped without generating an error alert. Which type of control is most notably absent?
Error handling and exception notification controls that alert operations staff when interface failures occur.
Encryption of the ACH file during transmission.
Role-based access controls on the payroll system.
Digital signature verification of ACH payment files.
Explanation
Silent failures indicate the absence of error handling and notification controls - the interface should detect failures and alert responsible staff immediately so corrective action can be taken. Answer C is correct. Encryption (A), access controls (B), and digital signatures (D) do not address the silent failure detection gap.
A company's procurement system automatically sends approved purchase orders to a supplier portal. Which of the following is the most critical interface control to implement?
Requiring suppliers to confirm receipt of each purchase order within 24 hours.
Restricting suppliers from viewing purchase orders older than 90 days.
Ensuring only fully authorized purchase orders (meeting all approval requirements) are transmitted to the supplier portal.
Encrypting the supplier portal's web interface with TLS.
Explanation
The most critical interface control ensures that only properly authorized transactions are transmitted - preventing unapproved orders from reaching suppliers and avoiding unauthorized commitments. Answer A is correct. TLS (B) addresses transit security. Supplier confirmation (C) is a business process control. Historical view restrictions (D) address access, not authorization.
A company uses an API to receive customer order data from an e-commerce platform and load it into its ERP system. Which of the following interface controls is most important to verify the authenticity of data received through this API?
Reconciling order counts between the e-commerce platform and the ERP weekly.
Storing all received API data in a separate staging table before processing.
Compressing the API data before transmission to improve performance.
Implementing API authentication (e.g., API keys, OAuth tokens) to ensure data is only accepted from the authorized e-commerce platform.
Explanation
API authentication controls verify that data is received from a legitimate, authorized source, preventing malicious or unauthorized parties from injecting data into the ERP system. Answer D is correct. Compression (A) is a performance measure. Staging tables (B) aid processing but don't verify authenticity. Weekly reconciliation (C) is detective, not preventive.
Which of the following is the primary risk associated with using flat file interfaces (such as CSV files) for transferring financial data between systems?
Flat files are not supported by standard encryption algorithms.
Flat file interfaces are incompatible with modern ERP systems.
Flat files cannot contain more than a few thousand records.
Flat files can be manually edited before processing, introducing errors or fraud if adequate controls are not in place.
Explanation
Unlike direct system-to-system APIs, flat files are discrete files that can be intercepted and manually altered before processing, creating a risk of unauthorized modification. Answer C is correct. Flat files are widely compatible (A) and can contain millions of records (B). Flat files can be encrypted (D).
A company's payroll interface generates a hash value of the payroll file before transmission and verifies the hash upon receipt. The purpose of this control is to:
Authenticate that the payroll file was sent by an authorized source system.
Detect any unauthorized modification or corruption of the payroll file during transmission.
Compress the payroll file to reduce transmission bandwidth.
Encrypt the payroll file during transmission to protect employee salary data.
Explanation
Hash verification detects changes to file content - if the hash upon receipt differs from the hash at transmission, the file was altered or corrupted during transit. Answer B is correct. Encryption (A) protects confidentiality. Hash verification detects changes but does not authenticate the sender (C). Compression (D) is unrelated to hashing.
Which of the following best describes the purpose of a 'staging area' or 'landing zone' in a system interface architecture?
A temporary holding area where incoming data is validated and cleansed before being loaded into the target production system.
A secure vault where encryption keys used by the interface are stored.
A backup copy of the target system maintained for disaster recovery purposes.
A monitoring console where IT staff review interface logs in real time.
Explanation
A staging area holds incoming data for validation, transformation, and cleansing before it enters the production target system, serving as a quality gate between source and destination. Answer B is correct. Key storage (A) is a key management function. Backup systems (C) serve disaster recovery. Monitoring consoles (D) are operational tools.
Which of the following is a key characteristic that distinguishes real-time (API-based) interfaces from batch interfaces from a controls perspective?
Real-time interfaces process individual transactions immediately, requiring controls that validate each transaction at the time of processing; batch interfaces process groups of transactions periodically, enabling control total verification across the batch.
Real-time interfaces are less secure than batch interfaces because they operate continuously.
Real-time interfaces eliminate the need for error handling because failures are immediately visible to users.
Batch interfaces do not require reconciliation because they process complete datasets.
Explanation
Real-time interfaces require per-transaction validation since there is no batch aggregation. Batch interfaces enable pre/post run control total comparisons across the group. Both have distinct control requirements. Answer A is correct. Real-time interfaces can be highly secure (B). Batch interfaces require reconciliation (C). Real-time interfaces absolutely require error handling (D).
An IT auditor is assessing the controls over a financial data interface and requests interface run logs for the past quarter. What information in these logs is most relevant to the audit?
Records of each interface execution including start/end times, record counts, error conditions, and any exceptions or failures.
The names of the IT staff members who developed the interface program.
The hardware specifications of the servers running the interface.
The source code of the interface program.
Explanation
Interface run logs document execution history - when the interface ran, how many records were processed, and any errors or failures. This information is essential for assessing completeness, reliability, and incident response. Answer C is correct. Developer names (A) and server specs (B) are not relevant to interface control testing. Source code review (D) is a separate IT audit procedure.
A company's interface transmits accounts payable data from a subsidiary to the parent company's consolidation system. An auditor verifies that the total accounts payable balance in the subsidiary's system equals the amount received by the parent's consolidation system. This audit procedure tests which assertion?
Valuation - confirming that accounts payable amounts are recorded at the correct amounts.
Existence - confirming that the accounts payable amounts are real obligations.
Completeness - verifying that all subsidiary accounts payable data was fully and accurately transferred to the consolidation system.
Rights and obligations - confirming the company has a legal obligation to pay the recorded amounts.
Explanation
Comparing source to target totals tests completeness of the data transfer - ensuring all data moved across the interface without loss. Answer B is correct. Existence (A) tests whether recorded items are real. Valuation (C) tests measurement. Rights and obligations (D) tests legal standing.