An e-commerce company stores customer payment information and order history on a cloud platform. The company needs to ensure that the stored data is…

Ephemeral storage is, by definition, non-persistent; its contents are lost when the associated compute instance is terminated or fails. The most significant threat of using this storage type for sensitive, transactional data like payment information is the high probability of permanent data loss. This directly compromises data availability and integrity. The correct mitigation strategy is to use a storage service designed for durability and persistence, such as cloud block storage or object storage, for any data that must be retained beyond the lifecycle of a single compute instance.

A. Unauthorized access is a general threat to all storage types, not a unique or primary threat stemming from the ephemeral nature of the storage.
B. Data leakage through APIs is a threat related to the management and access plane, not the underlying persistence characteristic of the storage medium.
C. The problem is a lack of persistence, not a "data persistence issue." Encryption is a control for confidentiality, not for preventing data loss on termination.

1. Microsoft Azure Documentation. (n.d.). Temporary disk. In Sizes for virtual machines in Azure. Retrieved from Microsoft Docs. "The temporary disk is not persistent... Data on the temporary disk may be lost during a resize operation, when you redeploy a VM, or when the underlying hardware fails."

2. Amazon Web Services. (n.d.). Amazon EC2 instance store. Retrieved from AWS Documentation. "The data in an instance store persists only during the life of its associated instance. If an instance reboots (intentionally or unintentionally), data in the instance store persists. However, data in the instance store is lost under any of the following circumstances: The underlying drive fails, The instance stops, The instance terminates."

3. Cloud Security Alliance. (2017). Security Guidance for Critical Areas of Focus in Cloud Computing v4.0. Page 103. Discusses the need to understand the differences between persistent and non-persistent storage in IaaS environments.