What must secret and private keys used to encrypt a PAN be encrypted with?

The correct answer is that secret and private keys used to encrypt a Primary Account Number (PAN) must be encrypted with a Key Encryption Key (KEK). This is because a KEK is specifically designed to provide an additional layer of security for the encryption of sensitive keys, such as secret or private keys.

When dealing with encryption in payment systems, where the protection of data like a PAN is paramount, it is essential to use strong encryption practices. KEKs are used to encrypt the Data Encryption Keys (DEKs) that actually perform the encryption of the data itself. This hierarchy of encryption ensures that even if a DEK were compromised, the KEK provides an additional barrier to accessing the sensitive keys used in the data encryption process.

In contrast, while the other options like Data Encryption Key (DEK), Secure Socket Layer (SSL), and Public Key Infrastructure (PKI) are related to encryption and security, they serve different purposes. The DEK is used to encrypt the actual data but should not be directly exposed. SSL provides a secure channel over a network but does not specifically encrypt cryptographic keys. PKI is a framework used to manage encryption keys and digital certificates, but it does not refer to the encryption of the keys themselves. Consequently