Data encryption

Organizations store and transmit massive volumes of sensitive information—customer data, financial records, intellectual property, employee data, and credentials—across connected systems and cloud services. Encryption helps reduce risk when data is:

• Stored on servers, endpoints, removable media, or cloud storage

• Transferred across networks (internet, internal networks, APIs)

• Shared with partners, vendors, or remote employees

• Exposed during security incidents, device loss, or unauthorized access

At a high level, encryption works like this:

1. Plaintext is encrypted using an algorithm (cipher) and an encryption key.

2. The output becomes ciphertext, which looks like random data.

3. Decryption uses the corresponding key to convert ciphertext back into plaintext for authorized use.

Modern encryption is typically used to support multiple security objectives, including:

• Confidentiality: prevents unauthorized reading of data

• Integrity: helps detect tampering (often via authenticated encryption or signatures)

• Authentication: verifies who sent data or who is requesting access

• Non-repudiation: helps prevent parties from denying legitimate activity (commonly via digital signatures)

There are two primary models:

Symmetric encryption

Symmetric encryption uses the same key to encrypt and decrypt data. It’s fast and efficient, which makes it common for encrypting large amounts of data (e.g., backups, databases, storage volumes).

Key consideration: both parties (or systems) must securely share and protect the same secret key.

Asymmetric encryption (public-key encryption)

Asymmetric encryption uses two keys:

• A public key (shared) for encryption

• A private key (kept secret) for decryption

Asymmetric encryption is often used for secure key exchange, identity, certificates, and digital signatures. It’s usually slower than symmetric encryption for large datasets, so many systems combine both approaches.

Encryption standards evolve over time. In practice, organizations commonly rely on:

• AES (Advanced Encryption Standard): widely used symmetric encryption for data at rest and many storage/backup use cases

• TLS (Transport Layer Security): encrypts data in transit for HTTPS and many application-to-application communications

• RSA / ECC: commonly used for certificates, key exchange, and digital signatures (ECC is often preferred for efficiency)

Note on legacy terms: you’ll still see “SSL” referenced online, but modern web encryption is implemented with TLS.

In many environments, the biggest challenge isn’t encrypting data—it’s managing keys safely and consistently. Strong encryption can be undermined by weak key handling.

Data encryption best practices

• Protect encryption keys end-to-end. Store keys separately from encrypted data, and restrict access using least privilege.

• Rotate keys on a schedule. Reduce risk and limit blast radius if a key is exposed.

• Centralize key management. Use a key management system (KMS) or equivalent controls for lifecycle management, auditability, and governance.

• Encrypt all sensitive data. Prioritize regulated data and high-impact datasets, but aim for consistent coverage to avoid blind spots.

• Monitor and audit access. Track key usage and access events, and investigate anomalies.

• Balance performance and security. Encryption should be strong, but also operationally efficient for real workloads and recovery timelines.

Encryption is one of the strongest defenses for protecting data, but no single control is a complete security strategy.

Encrypted data can still be exposed or compromised in a few common ways:

• Key theft: attackers gain access to encryption keys through phishing, credential theft, misconfiguration, or poor key storage practices

• Weak or outdated algorithms: legacy encryption standards can become vulnerable over time

• Implementation flaws: mistakes in how encryption is implemented can introduce weaknesses

• Compromised endpoints: malware on authorized devices can sometimes capture data before it’s encrypted or after it’s decrypted

Bottom line: the most common path to “breaking” encryption is not cracking the cipher—it’s stealing the keys or credentials that unlock it.

The primary benefits of data encryption include:

• Reduces breach impact. If encrypted data is stolen, it’s far less usable without keys.

• Protects confidentiality across environments. Supports secure cloud adoption, remote work, and multi-device access.

• Supports integrity and trust. Helps organizations protect data quality and prevent unauthorized changes.

• Strengthens compliance posture. Many regulatory frameworks expect encryption as a safeguard, especially for sensitive or regulated data.

• Protects intellectual property. Helps prevent unauthorized access to valuable digital assets.

• Improves customer confidence. Demonstrates a commitment to protecting personal and business data.

Data encryption solutions are commonly implemented based on where data lives and how it moves.

• For data at rest: storage encryption, database encryption, full disk encryption, file-level encryption, backup encryption

• For data in transit: TLS-based encryption, VPNs, encrypted API traffic, secure service-to-service communication

As organizations adopt cloud services, SaaS applications, and mobile workforces, encryption strategies also need to account for:

• Distributed data locations

• Multiple identities and access paths

• Key sprawl and key lifecycle management

• The need to recover and restore data securely after incidents

Data at rest does not travel between devices or networks. This kind of information includes data on a flash drive, database, hard drive, or laptop. The appeal of data at rest is that it frequently contains logical details such as suggestive file names that help hackers pinpoint and steal sensitive data including credit card numbers, healthcare information, intellectual property, and personal information.

Proper disposal of data assets is itself an important part of a security protocol because by eliminating unnecessary data you reduce your amount of data at rest and corresponding risk of exposure. For data at rest that remains, data encryption strategies can take place at four levels:

Application-level data encryption encrypts data where it is generated before it is written to the database. You can, therefore, customize the application level data encryption process based on individual user roles and permissions.

Database level data encryption refers to encrypting either the entire database or parts of it. At this level, the database system manages and stores encryption keys.

Storage-level encryption converts all data written to any type of storage into an indecipherable format automatically. This can be done by a physical device installed in the data path, or via software that runs at a device driver level.

Like storage-level encryption, device-level encryption automatically converts all stored data into an indecipherable format, except this encryption is done by the device itself. Device-level encryption can be either full disk encryption or tape drive encryption.

Like full disk encryption, file system level data encryption can encrypt entire databases and their contents. However, file system level data encryption enables users to encrypt individual files and directories using software agents. These agents determine whether data should be encrypted based on policies. This means the encryption is performed via software.

A practical approach to implementing data encryption includes:

1. Build a collaborative strategy. Involve security, IT, operations, and data owners. Map requirements and risks.

2. Classify data. Define sensitivity categories (e.g., regulated, confidential, internal) and where that data lives.

3. Define encryption coverage. Specify what must be encrypted at rest, in transit, and in backups.

4. Establish key management. Centralize keys, define lifecycle policies, implement access controls, and audit processes.

5. Limit access and enforce strong authentication. Combine encryption with IAM, MFA, and least privilege.

6. Validate and test. Ensure performance, recovery workflows, and audits operate correctly—especially for backup/restore scenarios.

Yes. Druva supports cloud data encryption using a digital envelope encryption approach. With envelope encryption, data is encrypted using a data encryption key, and that key is then protected using a higher-level key (often called a root key) as part of a structured key management model.

This approach is designed to support security and usability outcomes such as:

• Secure decryption workflows: decryption keys are used only when needed and are not meant to be broadly exposed

• Operational resilience: administrators can support recovery and access workflows without creating unnecessary lockout risk

• Key durability and governance: structured key management supports lifecycle controls and access policies

• Strong tenant separation: encryption models are designed to help ensure customer data remains protected and isolated

Next steps:

• Read the security briefs for Enterprise Workloads and End-Users to get the details

• Learn more about Druva’s platform and cyber resilience

• Explore how Druva enables recovery readiness for any threat

What is data encryption?

Data encryption converts readable data (plaintext) into an unreadable format (ciphertext) so that only authorized users or systems with the correct decryption key can read it.

How does data encryption work?

Encryption uses an algorithm and a key to transform plaintext into ciphertext. Decryption uses the corresponding key to convert ciphertext back into readable data.

What are the two main types of encryption?

The two main types are symmetric encryption (one shared secret key) and asymmetric encryption (a public key and a private key).

What is the difference between encryption at rest and encryption in transit?

Encryption at rest protects stored data (disks, databases, backups, cloud storage). Encryption in transit protects data moving across networks (HTTPS, APIs, service-to-service traffic), typically using TLS.

Is encryption enough to prevent a data breach?

Encryption helps reduce the impact of a breach, but it doesn’t prevent attacks on its own. Strong security also requires identity controls, monitoring, patching, segmentation, backups, and incident response.

Can encrypted data be hacked?

In many cases, attackers don’t “crack” strong encryption—they steal keys or credentials, exploit implementation flaws, or compromise authorized devices. That’s why key management is critical.

What are data encryption best practices?

Protect and rotate keys, centralize key management, encrypt sensitive data consistently, enforce least privilege, and audit key access and usage.

Does Druva provide data encryption?

Yes. Druva supports cloud data encryption using a digital envelope encryption approach designed to protect data while supporting secure access and recovery workflows.

Now that you’ve learned about data encryption, brush up on these related terms with Druva’s glossary:

• Data archiving
• eDiscovery
• Cloud data protection
• Data security
• Data loss prevention (DLP)
• Ransomware
• Zero trust