Data Security is a significant issue for every organization. With frequent data theft occurrences every day, safeguarding sensitive data has become crucial. To ensure data security, every organization should design secure systems and set up proper firewalls to avoid unauthorized access. But just securing your systems is not enough. Data security gets stronger with data encryption. This is where Transparent Data Encryption comes in.

SQL 2008 presented Transparent Data Encryption as a tool to protect data at ‘rest.’ Data at rest includes data files, log files, backup files, and more. It protects data by encrypting the files present in the database instead of the data itself. It performs data encryption based on Advanced Encryption Standard(AES) algorithms using a database encryption key or DEK.

This article will cover everything about Transparent Data Encryption. Read on to find out more about its working mechanism and the benefits and challenges associated with it.

What is Transparent Data Encryption, and how does it work?

Transparent Data Encryption permits you to encrypt data at ‘rest’ unlike the end to end encryption provided by Always On encryption for data in transit. It achieves this by encrypting files using Advanced Encryption Standard(AES) or Triple Encryption Standard(DES), then decrypting the data as it enters memory. ‘At rest’ data with regards to SQL database refers to any data files (.mdf) or log files (.ldf), backup files(.bak), database snapshot files, or any data put on a disk in the ‘TempB database.’tde

The working mechanism of Transparent Data Encryption is simple. It does input/output data encryption and decryption in real-time, using a database encryption key or DEK. It follows the encryption algorithms, such as requesting access to encrypted data from your database and providing an authorization key.

As you enter the key, Transparent Data Encryption will decrypt the data before sending it to you. This key refers to a key hierarchy in the MASTER database. Due to this dependency, you cannot view the data files outside of their level.encryption

These keys are placed in a Keystore detached from the database to avoid unauthorized access. As a result, an approved user can see the decrypted contents of the database files without making a special effort. The user is not even conscious that the innate data files are encrypted. However, if a data thief acquires access to the data files via an embezzled backup file will be unable to access the data it contains.

There are two formats for Transparent Data Encryption:

  • Full Disk Encryption: Full disk encryption works by encrypting all the data on a hard drive or other storage mediums. However, this encryption is only helpful in case someone steals the storage device.encryption
  • File System Encryption: File system encryption safeguards data at rest in distinguished locations, generally file or application servers. This method delivers security against undesirable outsider access and unauthorized insiders as well.

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Types of Transparent Data Encryption

Encryption of sensitive data is possible at the column level and tablespace level.

Column Level Encryption

Column-level encryption shields covert data in table columns, like credit card numbers or Social Security numbers. It operates based on a two-tiered key structure for the encryption process.column level tde

The master encryption key for transparent data encryption is kept in an external security unit, like Oracle software or hardware Keystore. This key is responsible for encrypting and decrypting the table key, which then encrypts and decrypts data in the table column.

Tablespace Level Encryption

Tablespace encryption enables you to encrypt the whole tablespace. It automatically encrypts all of the entities created within the encrypted tablespace. Tablespace encryption is helpful when your tables contain plenty of sensitive data in a different column. And also when you desire to secure the entire table.tablespace level encryption

While using this encryption, you do not require to examine individual columns to decide which ones need encryption. However, tablespace encryption does not encrypt any data kept outside the tablespace.

Merits of using Transparent Data Encryption

Using Transparent Data Encryption gives you an edge. Some benefits include the following:

  • As a security controller, you can rest assured because transparent data encryption ensures that sensitive data security is not hampered, even if the storage device or data file is stolen.
  • Transparent Data Encryption assists in following security-related guidelines.
  • It does not require additional tables, prompts, or views to decrypt data for the approved user or application. Data in the tables are decrypted transparently for the database user or encryption
  • Transparent Data Encryption does not require application modification to provide strong encryption of important data.
  • Data is noticeably decrypted for database users and applications that access it without being aware that the data they are trying to obtain is encryption
  • Employing online table redefinition, you can encrypt data on production systems with negligible downtime. You can also encrypt it offline while maintenance is going on.
  • The database manages the whole end-to-end encryption process; no additional tool is required to govern the data.

Stumbling Blocks of Transparent Data Encryption

Some disadvantages of Transparent Data Encryption include the following:tde process

  • It does not encrypt moving data or data contained inside an application, as it can only encrypt data at rest.
  • It encrypts all the other data in the database along with the sensitive data.
  • Compressed backups will greatly lessen the amount of compression performed.


What is transparent data encryption?

Transparent Data Encryption (TDE) lets you encrypt sensitive data stored in tables and tablespaces.

How does Transparent Data Encryption work?

TDE permits you to encrypt data at rest in the databases. It blocks unauthorized attempts to obtain data stored in files within the database without affecting how approved users access the data using SQL. It can encrypt entire application tablespaces or specific columns containing sensitive data.

Why is TDE called transparent?

Transparent data encryption protects data at the file level, presenting it transparently to the end user.

What algorithm does TDE use?

It primarily supports the Advanced Encryption Standard(AES) algorithms. You can pick which AES algorithm to use while setting up Transparent Data Encryption: AES 128, AES 192, or AES 256. The number signifies the length of the key used for encryption in bits.

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We hope this article helped you to understand all the basic information about Transparent Data Encryption. It is an excellent method to keep the ‘at rest’ data in the database safe and secure. Even though data encryption cannot prevent hackers from barging into the system, it will make it impossible for them to comprehend the data they stole. Transparent Data Encryption uses a single database encryption key or a DEK, which is stored away from the database, creating stronger security for the data.

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Aloukik Rathore is a Delhi-based entrepreneur, gadget lover, and absolute geek. He loves spending time learning about new innovations!