問題文
A payments company describes three treatments of card numbers: replacing each number with a surrogate value held in a separate vault, showing only the final four digits on screen, and storing the numbers under a key. Which naming and consequence is correct?
選択肢
- The surrogate is tokenization, the partial display is masking and the keyed storage is encryption so only tokenization removes the original card number from the storing system altogether and leaves it in the separate vault instead.
- Masking is the strongest of the three, because a value that is never shown in full cannot be stolen from the screen.
- The surrogate is masking, the partial display is encryption and the keyed storage is tokenization because masking is what replaces a value with a different one and tokenization is what protects a value with a key that the company holds separately.
- All three are forms of encryption, because all three make the original card number unavailable to somebody who is looking at the system and the difference between them is only in how the transformation is implemented.