Final Answer:
Encryption at rest is most frequently used at the host layer.
Step-by-step explanation:
Encryption at rest is a security measure employed to safeguard data stored on physical devices, such as hard drives or solid-state drives, when they are not actively in use.
This type of encryption is most commonly implemented at the host layer, where the data resides. Host layer encryption ensures that data remains protected even when the storage device is not actively transmitting or processing information.
By encrypting data at rest, organizations enhance their overall data security posture, mitigating the risk of unauthorized access in case of physical theft or unauthorized access to storage media. This is particularly crucial for safeguarding sensitive information and ensuring compliance with data protection regulations.