science

Transparent data encryption

Transparent data encryption is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Transparent data encryption rather than just read about it. In short: Transparent data encryption (often abbreviated to TDE) is a technology employed by Microsoft, IBM and Oracle to encrypt database files. TDE offers encryption at file level.

Key takeaways

Transparent data encryption belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Transparent data encryption to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Transparent data encryption from memory before moving on to harder problems.

Reference excerpt

Transparent data encryption (often abbreviated to TDE) is a technology employed by Microsoft, IBM and Oracle to encrypt database files. TDE offers encryption at file level. TDE enables the encryption of data at rest, encrypting databases both on the hard drive and consequently on backup media. It does not protect data in transit nor data in use. Enterprises typically employ TDE to solve compliance issues such as PCI DSS which require the protection of data at rest. Microsoft offers TDE as part of its Microsoft SQL Server 2008, 2008 R2, 2012, 2014, 2016, 2017 and 2019. TDE was only supported on the Evaluation, Developer, Enterprise and Datacenter editions of Microsoft SQL Server, until it was also made available in the Standard edition for 2019. SQL TDE is supported by hardware security modules from Thales e-Security, Townsend Security and SafeNet, Inc. IBM offers TDE as part of Db2 as of version 10.5 fixpack 5. It is also supported in cloud versions of the product by default, Db2 on Cloud and Db2 Warehouse on Cloud. Oracle requires the Oracle Advanced Security option for Oracle 10g and 11g to enable TDE. Oracle TDE addresses encryption requirements associated with public and private privacy and security mandates such as PCI and California SB 1386. Oracle Advanced Security TDE column encryption was introduced in Oracle Database 10g Release 2. Oracle Advanced Security TDE tablespace encryption and support for hardware security modules (HSMs) were introduced with Oracle Database 11gR1. Keys for TDE can be stored in an HSM to manage keys across servers, protect keys with hardware, and introduce a separation of duties. The same key is used to encrypt columns in a table, regardless of the number of columns to be encrypted. These encryption keys are encrypted using the database server master key and are stored in a dictionary table in the database.

Microsoft SQL Server TDE SQL Server utilizes an encryption hierarchy that enables databases to be shared within a cluster or migrated to other instances without re-encrypting them. The hierarchy consists of a combination of symmetric and asymmetric ciphers:

Windows Data Protection API (DPAPI) protects a single instance-wide Service Master Key (SMK). The Service Master Key encrypts the Database Master Key (DMK). The Database Master Key is used in conjunction with a certificate to encrypt the Database Encryption Key. The Database Encryption Key is used to encrypt the underlying database files with either the AES or 3DES cipher. The master database that contains various system level information, user accounts and management services is not encrypted. During database backups, compression occurs after encryption. Due to the fact that strongly encrypted data cannot be significantly compressed, backups of TDE encrypted databases require additional resources. To enable automatic booting, SQL Server stores the lowest level encryption keys in persistent storage (using the DPAPI store). This presents a potential security issue because the stored keys can be directly recovered from a live system or from backups and used to decrypt the databases.

See also Disk encryption Encryption Hardware security module

References

External links EaseFilter Transparent File Encryption Alternative 3rd party solution for all SQL Server Editions Another alternative 3rd party solution for all SQL Server Editions Enterprise Security Features Supported by Microsoft SQL Server 2008 R2 Editions Security Features Supported by Microsoft SQL Server 2012 Editions Understanding Transparent Data Encryption (TDE) (Microsoft) Using Transparent Data Encryption in Oracle Database 11g Oracle Transparent Data Encryption best practices TDE column encryption and TDE tablespace encryption in Oracle Database 11gR1 http://download.oracle.com/docs/cd/B19306_01/network.102/b14268/asotrans.htm#BABDFHHH P6R's PKCS#11 Provider and Oracle TDE [1]

Worked examples

Example 1 — a first encounter with Transparent data encryption

Start with the simplest possible case. Write down what Transparent data encryption claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Transparent data encryption before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Transparent data encryption ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Transparent data encryption

In research: Transparent data encryption appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Transparent data encryption in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Transparent data encryption is common in secondary-school and first-year university syllabi. It links to neighbouring topics Disk encryption, so understanding it makes those chapters shorter.
In everyday life: Look for Transparent data encryption outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Transparent data encryption in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Transparent data encryption means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Transparent data encryption out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Transparent data encryption in simple terms?

Transparent data encryption (often abbreviated to TDE) is a technology employed by Microsoft, IBM and Oracle to encrypt database files. TDE offers encryption at file level.

Why does Transparent data encryption matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Transparent data encryption?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Transparent data encryption.