Selecting the Right Encryption Approach

Full-disk encryption (FDE) and self-encrypting drives (SED) encrypt data as it is written to the disk and decrypt data as it is read off the disk.

FDE/SED Advantages:

• Simplest method of deploying encryption
• Transparent to applications, databases, and users.
• High-performance, hardware-based encryption

FDE/SED Limitations:

• Addresses a very limited set of threats—protects only from physical loss of storage media.
• Lacks safeguards against advanced persistent threats (APTs), malicious insiders, or external attackers
• Meets minimal compliance requirements
• Doesn’t offer granular access audit logs

Key takeaways:

• Mainstream cloud providers offer the functional equivalent of FDE with its attendant limitations listed above
• FDE makes sense for laptops, which are highly susceptible to loss or theft. But FDE isn’t suitable for the most common risks faced in data center and cloud environments

Learn More:

• Analyst Resources:
  • Aberdeen white paper: Selecting Encryption for “Data-At-Rest” In Back-End Systems: What Risks Are You Trying To Address
  • Aberdeen Infographic: Selecting the Right Encryption
  • Aberdeen short video: Selecting Encryption for “Data at Rest” in Back-End Systems
  • Aberdeen webinar: The Right Tools for the Job Encryption for Data at Rest in Back-End Systems

Relevant Thales eSecurity solutions:

• You can use Vormetric Key Management to manage encryption keys for on-premises FDE storage
• To enhance compliance with organizational and industry mandates around encryption key management, users of cloud provider encryption (essentially equal to FDE) can use either the CipherTrust Cloud Key Manager or nShield Bring Your Own Key to take control of data encryption keys from cloud providers.

Encrypting data at the file or volume (typically used for databases) level offers security controls with software agents installed in the operating system. Agents intercept disk reads and writes and apply policies to determine if the data should be encrypted or decrypted. Mature file-system encryption products offer strong policy-based access controls, including for privileged users and processes, and granular logging capabilities.

File-Level Encryption Advantages:

• Transparent to users and applications, meaning organizations don’t have to customize applications or change associated business processes
• Supports both structured and unstructured data
• Establishes strong controls that guard against abuse by privileged users and that meet common compliance requirements
• Offers granular file access logs and SIEM integration that can be used for security intelligence and compliance reporting

File-Level Encryption Limitations:

• Encryption agents are specific to operating systems, so it is important to ensure the solution selected offers coverage of a broad set of Windows, Linux, and Unix platforms

Key takeaways:

• For many organizations and purposes, file encryption represents the optimal approach. Its broad protections support the vast majority of use cases, and it is easy to deploy and operate.

Relevant Thales eSecurity solutions and capabilities:

• Vormetric Transparent Encryption offers encryption of structured and unstructured files along with strong privileged user access controls.
• Vormetric Security Intelligence offers robust capabilities for leveraging granular security logs.

Other considerations:

• File-level encryption can protect any database that is in a file on a supported operating system. This is common in Microsoft Windows SQL Server for smaller databases. Volume-level encryption can provide encryption for very large databases. Database protection is typically multi-layered. A good security practice beyond database encryption is a database activity monitoring (DAM) product to protect against such threats as malicious database administrator or compromised DBA credentials, or SQL injection attack.

This approach enables security teams to encrypt a specific subset of data within the database or the entire database file. This category includes solutions from multiple database vendors that are known as transparent data encryption (TDE).

Advantages:

• Safeguards data in databases, which are critical repositories.
• Establishes strong safeguards against a range of threats, including malicious insiders—even in some cases a malicious database administrator.

Limitations:

• Offerings from one database vendor can’t be applied to databases from other vendors.
• Doesn’t enable central administration across multiple vendor databases or other areas in environment.
• Only encrypts columns or tables of a database, leaving configuration files, system logs, and reports exposed.

The takeaway:

• While database encryption technologies can meet specific, tactical requirements, they don’t enable organizations to address security across heterogeneous environments. As a result, they can leave organizations with significant security gaps.

Learn more:

• Relevant Thales eSecurity solutions:
  • Vormetric Data Security Platform offers several database security solutions.
  • Vormetric Key Management can be used to manage TDE cryptographic keys.

When employing this approach, application logic is added to govern the encryption or tokenization, of data from within the application.

Advantages:

• Secures specific subsets of data, such as fields in a database.
• Encryption and decryption occur at the application layer, which means data can be encrypted before it is transmitted and stored.
• Offers highest level of security, providing protections against malicious DBAs and SQL-injection attacks.
• Tokenization can also significantly reduce PCI DSS compliance costs and administrative overhead.

Limitations:

• These approaches need to be integrated with the application, and therefore require development effort and resources.

The takeaway:

• These approaches may be optimal in cases in which security policies or compliance mandates require specific sets of data to be secured. In addition, variants of application-layer encryption, including tokenization and format-preserving encryption, can help reduce the impact on databases.
• Look for solutions with well-documented, standards-based APIs and sample code to simplify application development.

Learn more:

• Relevant Thales eSecurity solutions:
  • Vormetric Application Encryption simplifies the process of adding encryption into existing applications.
  • Vormetric Tokenization simplifies the process of adding tokenization and dynamic data masking into existing applications.