datainuse

Data in use refers to data that is actively being processed by a computer system. It is one of the three traditional data states in information security, alongside data at rest (stored data) and data in transit (data moving across networks). Data in use exists in memory and during computation, in CPU registers and caches, as applications read, transform, or analyze information.

Because data in use is loaded into volatile memory for processing, it is particularly vulnerable to certain threats. Memory-resident malware, side-channel attacks, and inadvertent data exposure through memory dumps or poor coding practices can reveal unencrypted information while it is being processed. Protecting data in use therefore requires approaches that differ from those used for data at rest or in transit.

Techniques to secure data in use include hardware-assisted trusted execution environments (TEEs) such as Intel SGX and AMD SEV, which isolate computations and protect data in protected memory. Memory encryption and secure attestation help ensure confidentiality and integrity of data during processing. Cryptographic methods like fully homomorphic encryption and secure multi-party computation enable some processing on encrypted data, reducing exposure. Oblivious RAM and side-channel resistant algorithms aim to conceal access patterns and timing information. Software engineering practices, such as constant-time implementations and minimizing the amount of data processed, also contribute to stronger data-in-use protections.

Applications span cloud computing, privacy-preserving analytics, and regulated industries where sensitive data must be processed securely. Data in use protections are central to privacy-preserving machine learning, genomic and financial data analysis, and secure collaboration across organizations. Ongoing research continues to address performance overheads and broader adoption of TEEs and advanced cryptographic techniques.