Glossary

Encryption at rest is a security measure that protects stored data by converting it into an unreadable format using cryptographic algorithms. Unlike encryption in transit, which secures data as it moves between systems, encryption at rest ensures that sensitive information remains protected even when it is not actively being used. This safeguard is essential for databases, cloud storage, backups, and any other data repositories where information is stored for long periods.

The primary goal of encryption at rest is to prevent unauthorized access, especially in cases where physical storage media is lost, stolen, or accessed by malicious actors. Without the proper decryption keys, encrypted data remains indecipherable, mitigating the risks associated with data breaches and unauthorized disclosures. Organizations handling sensitive information, such as financial institutions, healthcare providers, and SaaS platforms, implement encryption at rest as a fundamental security practice to maintain compliance with regulations like GDPR, HIPAA, and PCI-DSS.

Common techniques for encryption at rest include full-disk encryption (FDE), file-level encryption, and database encryption. Full-disk encryption secures entire storage devices, ensuring that all stored data is protected. File-level encryption provides more granular control by encrypting individual files or folders, while database encryption focuses on securing structured data within database management systems. These approaches often leverage strong encryption standards like AES-256, which offers robust protection against brute-force attacks.

While encryption at rest significantly enhances data security, it is only effective when combined with proper key management. Secure key storage, rotation policies, and access controls are necessary to prevent unauthorized decryption. Many organizations use hardware security modules (HSMs) or cloud-based key management services (KMS) to securely generate, store, and manage encryption keys.