Definition
Data in use refers to information actively being processed or manipulated by a system or application. This state contrasts with data at rest, which is stored, or data in transit, which is being transmitted across a network. In practice, protecting data in use involves securing the memory and processing environments where computations occur. This is crucial because compromised processing environments can expose sensitive information even if storage and transmission are encrypted. For instance, a financial application processing a credit card transaction handles data in use, making the application's memory a target for attackers. Unlike data at rest which is protected by disk encryption, data in use requires different security controls like memory protection and secure coding practices. Understanding data in use is essential for cybersecurity certifications such as CompTIA Security+ and CISSP.