IPSec is a protocol for encrypting and authenticating packets during transmission between two parties and can involve any type of device, application, or service. The protocol performs both the authentication and negotiation of security policies between the two parties at the start of the connection and then maintains these policies throughout the lifetime of the connection. TLS operates at the application layer, not the network layer, and is widely used to secure communications between two parties. SSL is similar to TLS but has been deprecated. Although a VPN allows a secure channel for communications into a private network from an outside location, it's not a protocol.

Explanation
The data owner is usually considered the cloud customer in a cloud configuration; the data in question is the customer's information, being processed in the cloud. The cloud provider is only leasing services and hardware to the customer. The cloud access security broker (CASB) only handles access control on behalf of the cloud customer, and is not in direct contact with the production data.