Definition
Encryption at Rest
Encryption at rest protects data while it is stored — on disks, in databases, in backups — by keeping it encrypted so that anyone who gains physical or low-level access to the storage cannot read it without the keys. It complements encryption in transit, which protects data moving over the network, to give end-to-end protection across a data's lifecycle.
Key takeaways
- Encryption at rest stores data as ciphertext on disk, in databases, and in backups so stolen storage is unreadable without the keys.
- It typically uses a strong cipher like AES-256, often in an authenticated mode (GCM) that also detects tampering.
- Its security hinges on key management — keys kept separate from the data, rotated, and tightly access-controlled.
- It is necessary but not sufficient: it must be paired with encryption in transit (TLS) and proper access controls.
Data spends most of its life sitting still — in database files, object storage, snapshots, and backups. If an attacker steals a disk, copies a backup, or accesses raw storage, plaintext data is immediately exposed. Encryption at rest defends against exactly this by storing the data as ciphertext; without the decryption key, the bytes on disk are meaningless.
Modern systems typically use a strong symmetric cipher such as AES-256, often in an authenticated mode like GCM that also detects tampering. The security ultimately depends on key management: keys must be stored separately from the data they protect, rotated periodically, and access-controlled, often via a dedicated key management service or hardware security module.
Encryption at rest is necessary but not sufficient. It must be paired with encryption in transit (TLS) so data is protected both while stored and while moving, and with access controls so authorized callers still only see what they should. Together these form the baseline that compliance frameworks expect.
Planoda encrypts customer data at rest with AES-256-GCM and in transit with TLS 1.3, so data is protected both while stored and while moving between client and server.
Related terms
- SOC 2SOC 2 is an auditing standard from the AICPA that assesses how a service organization handles customer data against five trust service criteria: security, availability, processing integrity, confidentiality, and privacy. A SOC 2 report, produced by an independent auditor, is the common way SaaS vendors demonstrate to customers that their controls are designed and operating effectively.
- GDPRThe General Data Protection Regulation is the European Union's comprehensive data-protection law, in force since 2018. It governs how organizations collect, process, and store the personal data of people in the EU, granting individuals rights over their data — access, correction, deletion, portability — and imposing strict obligations on data handlers, backed by fines of up to 4% of global annual revenue.
- Principle of Least PrivilegeThe principle of least privilege holds that every user, service, or process should be granted only the minimum permissions needed to do its job — and nothing more. By default-denying access and granting narrowly, you shrink the attack surface: a compromised account or buggy component can only reach what it was explicitly allowed, limiting the blast radius of any failure.
- Row-Level Security (RLS)Row-level security (RLS) is a database feature that restricts which rows a query can read or modify based on the current user or context. Instead of relying solely on application code to filter data, the database itself enforces access policies on every query — a strong defense for multi-tenant systems where one workspace's data must never leak to another.
- Audit TrailAn audit trail is an append-only, time-ordered record of who did what, when, and to which object across a system. Every create, edit, delete, and approval is logged immutably, so any state can be traced back to the actions that produced it. Audit trails underpin accountability, debugging, compliance, and — increasingly — oversight of what AI agents do.