Explanation: Cryptographic erasure involves having the data encrypted, typically as a matter of standard operations, and then rendering the data useless and unreadable by destroying the encryption keys for it. It represents a very cheap and immediate way to destroy data, and it works in all environments. With a cloud environment and multitenancy, media destruction or the physical destruction of storage devices, including shredding, would not be possible. Depending on the environment, overwriting may or may not be possible, but cryptographic erasure is the best answer because it is always an available option and is very quick to implement.