What’s data at rest — and how do you protect it?

Most engineers and IT leaders focus on securing data in motion or in use — but they forget that data at rest is just as vulnerable. Even when it’s not actively moving between systems, sensitive information like names, Social Security numbers, credit card data, and health records still needs strong encryption to keep it safe. 

Failing to protect data at rest can expose your business to breaches, legal consequences, and loss of customer trust. To stay compliant and secure, stored data must be inaccessible without a valid encryption key — no exceptions.

Here’s what you need to know to safeguard data at rest across your systems.

What’s data at rest?

Data at rest refers to stored information that’s not actively moving through systems or networks. This includes data housed on physical media like hard drives and servers, as well as cloud platforms like Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP).

While it may seem secure, data at rest is still vulnerable to corruption, breaches, and unauthorized access — especially if it isn’t encrypted. Internal threats can be just as dangerous as external ones. To protect stored data and maintain compliance, organizations must implement safeguards like data at rest encryption, strong access controls, physical security measures, and continuous monitoring.

Common threats to data at rest

Major data breaches remain a constant threat as hackers grow more sophisticated and stored data becomes more valuable. Inactive data is especially vulnerable to attacks from malicious actors or malware. While most companies use Secure Sockets Layer (SSL) to protect data in transit or in use, data at rest often lacks the same level of protection.

Hackers frequently target stored data because it's assumed to be important — and thus worth stealing. Long-term storage typically includes sensitive financial or health information governed by regulations like HIPAA. A breach doesn't just risk compliance violations; it can lead to major financial losses and lasting reputational damage.

Ways your data at rest may be at risk

Even with encryption in place, there are still several common ways data at rest can be exposed. Common risks include:

• Weak access controls: Single-factor authentication or poorly managed permissions can allow unauthorized access.
• Media theft or loss: When laptops, hard drives, and flash drives are lost or stolen, their contents are more easily accessed if unencrypted.
• Vulnerable backups: Unencrypted backups, outdated algorithms like DES, or weak key management can all lead to leaks.
• Insider threats: Employees, contractors, or partners may misuse data — whether through negligence or intentional harm.

How is data at rest different from data in use or data in transit?

There are three states of data: data at rest, data in motion, and data in use. 

Data at rest

Data at rest refers to stored information — whether structured or unstructured — that isn’t actively moving or being processed. This includes files on physical devices like laptops and hard drives, as well as data in cloud storage.

Common risks include theft of physical media, accidental exposure, data degradation, and insider threats. To mitigate them, organizations should use encryption, role-based access control, multi-factor authentication, and data masking.

Data in transit

Data in transit is information actively moving through a network—for example, when sending emails, uploading files, or messaging via apps like Slack or Teams.

This state is most vulnerable to interception via man-in-the-middle attacks, eavesdropping, or Wi-Fi exploits. To keep data in transit secure, companies should implement HTTPS, VPNs, firewalls, and multi-factor authentication.

Data in use 

Data in use refers to information currently being processed by applications or accessed by users, like editing a cloud-based document or querying a database.

Risks include malware, phishing, human error, and unauthorized sharing. Even encrypted data can be mishandled while in use. Protection strategies include strong access controls, continuous authentication, encryption, and keeping systems and software updated.

Protecting data at rest in cloud and hybrid environments

Organizations with cloud or hybrid architectures face added complexity when securing data at rest. In cloud environments, stored data may live in SQL databases, warehouses, S3 buckets, or backups — all of which must be protected with strong encryption and access controls to prevent breaches, corruption, or ransomware.

Hybrid environments add further risk by spreading data across cloud services and on-prem systems like servers or hard drives. Ensuring consistent protection across both requires careful key management, role-based access, and compliance alignment.

If you handle sensitive or regulated data — like information covered by HIPAA or PCI DSS — securing data at rest isn't optional. It's critical for avoiding costly fines and maintaining customer trust.

How to protect data at rest: 4 methods for improved security

These four data at rest encryption methods help reduce risk and strengthen protection.

Encryption at rest

Encryption at rest is what works best for protecting stored data. You can encrypt files, specific databases, or entire disks — depending on your architecture. Always secure encryption keys using a cryptographic key management service (KMS) to prevent unauthorized access.

Data federation

Data federation lets you query data across systems without physically moving it. By reducing data movement, you limit exposure during transfer and keep sensitive information centralized and secure.

Secure key management

Encryption is only as strong as your key management. A reliable KMS generates strong, unpredictable keys and restricts access to authorized users only, blocking brute-force and insider attacks.

Access control

Limit access using the principle of least privilege — users should only see what they need. Maintain detailed logs to monitor access and detect unusual patterns that could signal a threat.

Best practices for protecting data at rest in modern cloud architectures

For cloud and hybrid environments, data at rest protection requires a layered approach. Follow these best practices:

1. Maintain an accurate data inventory: Centralize stored data and run regular audits to track new apps, eliminate redundancies, and catch outdated or orphaned data. Disorganized systems are more prone to breaches, while regular reviews improve visibility and control.
2. Implement strong key management: Use secure key generators and centralized repositories to protect encryption keys. Hybrid and cloud-first organizations should adopt cloud-native KMS tools that manage keys across both cloud and on-prem environments.
3. Establish consistent encryption: Apply encryption uniformly across all stored data, including backups and archives. Without the decryption key, encrypted data is unreadable to attackers, making it one of the most effective defenses.
4. Use multi-factor authentication (MFA): MFA adds an extra layer of protection by requiring multiple credentials, like a password and a one-time code or biometric scan. Even if one factor is compromised, MFA greatly reduces the risk of unauthorized access.

How Fivetran keeps your data secure from breaches 

Fivetran delivers enterprise-grade data security for modern cloud and hybrid architectures. As a fully managed platform, it protects data at rest across every stage of the pipeline — from source to storage — while helping you meet compliance standards and reduce operational risk.

Fivetran safeguards your data at rest by:

• Encrypting all data at rest and in transit using robust, industry-standard protocols to prevent unauthorized access and data leaks
• Using a fully managed data extraction tool to maintain secure, compliant ingestion pipelines
• Logging all schema changes, metadata updates, and lineage, enabling full traceability and streamlined auditing
• Eliminating manual data extraction and ad hoc transfers, which are common sources of security vulnerabilities
• Protecting all destinations — including cloud data lakes and warehouses — with built-in access controls and encryption at every step

Ready to secure your data with the most trusted name in automated data movement? Book a demo with Fivetran today.

FAQs

What encryption solutions are available for securing data at rest?

Data at rest can be protected with full-disk encryption, database-level encryption, or file-level encryption. These methods typically use the Advanced Encryption Standard (AES) to defend against unauthorized access.

What technologies or methods are best for encrypting data at rest?

Full Disk Encryption (FDE) and Transparent Data Encryption (TDE) are widely used for securing stored data. Pair encryption with strong key management to prevent breaches through stolen or exposed credentials.

How do backups relate to data at rest?

Backups are a type of data at rest and require the same level of protection. Secure them using encryption, access controls, and multi-factor authentication (MFA) to prevent leaks, corruption, or unauthorized access.

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