Samsung Pay uses tokenization to protect your card and payment information.
Samsung Pay is also secured by Samsung Knox which includes a security design whereby highly sensitive information - such as fingerprint and payment information - are kept on a separate computer area known as a 'secure environment'. Normal applications or malware have no access to the information inside.
When you make a payment, you'll need to authenticate your identity by using your fingerprint or Samsung Pay PIN before the information can be sent to the payment terminal. The merchant will only receive a token, and your payment information will be kept secure. The token will be sent to the payment network, where it will be decrypted and verified against the information stored in a secure internal network.
Once authenticated, the payment will be approved and sent back to the merchant. Only the payment network and your bank will have information about the transaction.