The concept of shares within a cloud environment is used to mitigate and control the request for resource allocations from customers that the environment may not have the current capability to allow. Shares work by prioritizing hosts within a cloud environment through a weighting system that is defined by the cloud provider. When periods of high utilization and allocation are reached, the system automatically uses scoring of each host based on its share value to determine which hosts get access to the limited resources still available. The higher the value a particular host has, the more resources it will be allowed to utilize.

Fault tolerance allows a system to continue functioning, even with degraded performance, if portions of it fail or degrade, without the entire system or service being taken down. It can detect problems within a service and invoke compensating systems or functions to keep functionality going. Although redundancy is similar to fault tolerance, it is more focused on having additional copies of systems available, either active or passive, that can take up services if one system goes down. Elasticity pertains to the ability of a system to resize to meet demands, but it is not focused on system failures. Automation, and its role in maintaining large systems with minimal intervention, is not directly related to fault tolerance.

Regardless of the cloud service category used, the physical environment is always the sole responsibility of the cloud provider. In many instances, the cloud provider will supply audit reports or some general information about their physical security practices, especially to those customers or potential customers that may have regulatory requirements, but otherwise the cloud customer will have very little insight into the physical environment. With IaaS, the infrastructure is a shared responsibility between the cloud provider and cloud customer. With all cloud service categories, the data and governance are always the sole responsibility of the cloud customer.

Explanation/Reference:
Explanation:
The handshake protocol negotiates and establishes the connection as well as handles the key exchange and establishes the session ID. It does not perform the actual encryption of data packets.