What is a unique feature of the DUKPT key-management technique?

The DUKPT (Derived Unique Key Per Transaction) key-management technique is specifically designed to enhance transaction security by creating a unique key for each individual transaction. This is achieved using a base key that is derived from a master key, combined with non-secret transaction-specific data, such as transaction counters.

This method ensures that even if one transaction key is compromised, previous and subsequent transaction keys remain secure, significantly minimizing the likelihood of a widespread breach. In practice, this approach provides a robust layer of security for electronic transactions, particularly in environments like credit card processing, where maintaining data integrity and protecting against fraud are critical.

The options that suggest using the same key for all transactions, relying solely on secret data, or generating keys purely from numeric data do not accurately reflect the principles underlying DUKPT, which emphasizes the importance of generating distinct transaction-specific keys to enhance overall security.