Gavin Payne

Transparent Data Encryption

The Hows, Whys and Whens

• Introduction to Encryption

• SQL Server Encryption Concepts

• Transparent Data Encryption

• Demo

• Considerations

Introduction

60 minutes

Gavin Payne

Solution Architect 3.5 yearsSQL Server DBA 10 years

SQL Bits 7SQL Server User GroupSQL Social

Blog http://blog.gavinpayneuk.comTwitter @GavinPayneUK

About Me

• We all have information we want to hide from others

To save embarrassmentTo keep trade secrets secretTo comply with regulatory compliance (e.g. PCI-

DSS)To comply with legal requirements (e.g. DPA)

• However:

Some people might actively try and steal dataSome people might accidentally find it

Why Encrypt?

• Plaintext

• Cipher

• Key

• Ciphertext

Simple Encryption ConceptsPlaintextABCDEF

CipherCiphertextNHYGFHLD

Key

PlaintextABCDEF

CipherCiphertextNHYGFHLD

Key

• Symmetric encryption

Where the same key is used to encrypt AND decrypt

Very fast but requires secure transport of the key

• Asymmetric encryption

Public key encryptionDifferent keys are used to encrypt and decryptEither key on its own is useless

Common Encryption Terms

PUBLICPUBLIC PRIVATE

PUBLIC PRIVATEPRIVATE

• Key

Must assume the cipher is known and available Key makes the execution of the cipher

unique

• Certificate

Confirms the owner of a public keyUsing a verifiable 3rd party digital

signature

Common Encryption Concepts

dhuiowe5 hvg5u84yv87905yv89y4789ny3v8924ytc79wdrnywgdrygsdfh

Why Is Database Encryption Needed?

Database Encryption Methods

Storage Hardware I/O controller encryption

File System EFS, BitLocker etc.

Database Physical Storage Transparent Data Encryption

Database Logical Storage SQL Server Column Encryption

Application Application Column Encryption

• SQL Server has a large internal encryption hierarchy

• Very flexible and self-sufficient

• All manageable via T-SQL

• Can hook into external encryption hardware

• Make sure you understand how to backup/restore!

SQL Server Encryption

• Common term also used by Oracle

• Transparent Data Encryption is new in SQL Server 2008

• Enterprise Edition only feature

• Designed to protect data against unauthorised access at rest (MDFs, LDFs and backups)

• You can steal my disks but not my data

What is TDE?

• Turnkey database storage encryption tool

• Transparent to applications and code

• Operates at the IO level within SQL Server

• A slight performance overhead (approx 6%)

• As dev’s strive to reduce database IO the effect of encryption is also reduced

What is TDE?

• Enterprise Edition feature suggests enterprise need

• Primarily financial services and healthcare

• But theft of any data is grabbing more headlines

• Delivers complete database storage encryption

• With a comprehensive management framework

When to use TDE

• System/Service Master Key

• Database Master Key

• Server Certificate

• Database Encryption Key

TDE Components

Demo

• Backup SMK

• Create a new user database

• Create DMK, cert, DEK

• Encrypt

• DMVs

• Backup and then restore elsewhere

Demo Summary

• Key and certificate management is crucial

• Backup compression benefits lost entirely

• Backup portability severely hampered

• IO overhead quoted at about 6%

• Tempdb gets encrypted for everyone

Things to be aware of

• Encryption is based upon ciphers and keys

• Nothing new in the database world

• Although such a turnkey and complete option is

• Key management within SQL Server is crucial

• Backups and tempdb get encrypted as well as

data

Summary