What does Encapsulated Security Payload (ESP) guarantee in data transmission?

Encapsulated Security Payload (ESP) is a component of the Internet Protocol Security (IPsec) suite, which provides various features to secure data as it travels across a network. One of the primary guarantees that ESP provides is the confidentiality of the data through encryption, which ensures that unauthorized parties cannot read the content being transmitted.

In addition to encryption, ESP also provides integrity protection. This means that it checks for any modifications or tampering of the data during transmission. By ensuring that the data has not been altered in transit, ESP helps maintain the trustworthiness of communication between systems.

Therefore, the correct answer highlights both of these key functions: the prevention of data modification and the encryption of the transmitted data, effectively securing the communication channel. This dual functionality is why ESP is an integral part of securing network communications in various applications.

The other options do not accurately capture the primary capabilities of ESP, as it neither solely focuses on modification nor on address verification or unencrypted communication.