EFD PROFESSIONAL CERTIFICATION
ADVANCED LEVEL 2026/2027
QUESTIONS WITH CORRECT
DETAILED ANSWERS LATEST UPDATE
THIS YEAR
1. What is the primary architectural difference between a hardware-based Sales Data
Controller (SDC) and a Virtual Sales Data Controller (VSDC)?
A. VSDC requires local physical storage for every transaction.
B. Hardware SDC operates independently of the POS system’s operating system.
C. VSDC cannot perform real-time digital signing of fiscal receipts.
D. Hardware SDC uses cloud-based HSMs for signature generation.
Answer: B
Conceptual Explanation: Hardware SDCs are external modules that process data
independently of the host OS, whereas VSDCs are software-based and often reside in the
cloud or within the application layer.
2. In the context of EFD security, what does ‘non-repudiation’ specifically ensure regarding
fiscal data?
A. The taxpayer cannot deny the authenticity of the issued receipt.
,B. The data is encrypted during transmission to prevent eavesdropping.
C. The EFD system remains operational during a network outage.
D. The tax rates are automatically updated from the central server.
Answer: A
Conceptual Explanation: Non-repudiation ensures that the sender of a digital signature
cannot later deny having signed the data, providing legal proof of the transaction.
3. When a ‘Global Internal Error’ code is returned by an EFD during a high-volume transaction
period, which factor is most likely the cause in a multi-thread environment?
A. Incorrect tax category mapping.
B. Printer paper out sensor triggering a software interrupt.
C. Race conditions during access to the Secure Element.
D. Expired digital certificate on the client side.
Answer: C
Conceptual Explanation: In high-volume environments, concurrent requests to a single
Secure Element can cause race conditions or resource locking, leading to internal
processing errors.
4. Which cryptographic algorithm is currently the standard for generating the Digital
Signature in Tier-1 EFD systems to ensure long-term security?
A. DES (Data Encryption Standard)
, B. Base64 Encoding
C. MD5 Hashing
D. ECDSA (Elliptic Curve Digital Signature Algorithm)
Answer: D
Conceptual Explanation: ECDSA provides a higher security level with smaller key sizes
compared to RSA, making it ideal for the resource-constrained Secure Elements used in
EFDs.
5. What is the impact of a ‘Fiscal Memory Full’ status on an Electronic Cash Register (ECR)?
A. The device switches to training mode automatically.
B. The device enters a locked state and prevents further sales.
C. The device allows transactions but stops printing QR codes.
D. The device overwrites the oldest records in the memory.
Answer: B
Conceptual Explanation: Fiscal regulations generally require that once the non-volatile
fiscal memory is full, the device must cease operation until the memory is replaced or
audited.
6. In an EFD system, what is the specific purpose of the ‘Internal Data Identifier’ (IDI)?
A. To uniquely identify a specific transaction within the Secure Element’s audit trail.
B. To track the GPS coordinates of the POS terminal.
ADVANCED LEVEL 2026/2027
QUESTIONS WITH CORRECT
DETAILED ANSWERS LATEST UPDATE
THIS YEAR
1. What is the primary architectural difference between a hardware-based Sales Data
Controller (SDC) and a Virtual Sales Data Controller (VSDC)?
A. VSDC requires local physical storage for every transaction.
B. Hardware SDC operates independently of the POS system’s operating system.
C. VSDC cannot perform real-time digital signing of fiscal receipts.
D. Hardware SDC uses cloud-based HSMs for signature generation.
Answer: B
Conceptual Explanation: Hardware SDCs are external modules that process data
independently of the host OS, whereas VSDCs are software-based and often reside in the
cloud or within the application layer.
2. In the context of EFD security, what does ‘non-repudiation’ specifically ensure regarding
fiscal data?
A. The taxpayer cannot deny the authenticity of the issued receipt.
,B. The data is encrypted during transmission to prevent eavesdropping.
C. The EFD system remains operational during a network outage.
D. The tax rates are automatically updated from the central server.
Answer: A
Conceptual Explanation: Non-repudiation ensures that the sender of a digital signature
cannot later deny having signed the data, providing legal proof of the transaction.
3. When a ‘Global Internal Error’ code is returned by an EFD during a high-volume transaction
period, which factor is most likely the cause in a multi-thread environment?
A. Incorrect tax category mapping.
B. Printer paper out sensor triggering a software interrupt.
C. Race conditions during access to the Secure Element.
D. Expired digital certificate on the client side.
Answer: C
Conceptual Explanation: In high-volume environments, concurrent requests to a single
Secure Element can cause race conditions or resource locking, leading to internal
processing errors.
4. Which cryptographic algorithm is currently the standard for generating the Digital
Signature in Tier-1 EFD systems to ensure long-term security?
A. DES (Data Encryption Standard)
, B. Base64 Encoding
C. MD5 Hashing
D. ECDSA (Elliptic Curve Digital Signature Algorithm)
Answer: D
Conceptual Explanation: ECDSA provides a higher security level with smaller key sizes
compared to RSA, making it ideal for the resource-constrained Secure Elements used in
EFDs.
5. What is the impact of a ‘Fiscal Memory Full’ status on an Electronic Cash Register (ECR)?
A. The device switches to training mode automatically.
B. The device enters a locked state and prevents further sales.
C. The device allows transactions but stops printing QR codes.
D. The device overwrites the oldest records in the memory.
Answer: B
Conceptual Explanation: Fiscal regulations generally require that once the non-volatile
fiscal memory is full, the device must cease operation until the memory is replaced or
audited.
6. In an EFD system, what is the specific purpose of the ‘Internal Data Identifier’ (IDI)?
A. To uniquely identify a specific transaction within the Secure Element’s audit trail.
B. To track the GPS coordinates of the POS terminal.
