Protect Your
Data's Privacy!
Data Encryption with
SQL Server
Joe Kuemerle
@jkuemerle
www.kuemerle.com
Background of Joe
Kuemerle
• Lead Developer at BookingBuilder Technologies
• Over 15 years of development experience with a
broad range of technologies
• Focused on application and data security, coding
best practices and regulatory compliance
• Presenter at community, regional and national
events.
What Is Encryption
What Is Encryption
Encryption is the process of mathematically
altering data in a consistent, reversible fashion. It
should be used to store sensitive information that will
need to be retrieved later. Encryption relies on a
secret that is the only viable way to reverse the
mathematical process
•
Encryption can be Symmetric where a single
value (the encryption key) is used to both encrypt
and decrypt the data
•
Or Encryption can be Asymmetric where there
are two values in that data encrypted with Value 1
can only be decrypted with Value 2 and vice versa.
This is also know as Public Key Encryption
•
What Is Encryption
“Encryption is the process of
substituting a small secret in
place of a large secret”
Symmetric Encryption
Asymmetric
Encryption
Certificates
• Certificates are used to store asymmetric keys and
consist of a private key and public key.
• SQL Server provides built in management of
certificates
• Do not use use certificates to encrypt data, it is slow
and can be vulnerable when storing lengthy values.
Use a symmetric key to encrypt the data and a
certificate to encrypt the symmetric key.
Hashes
• Hashes are not an encryption method. A hash
takes an input value and transforms it to a unique
value that is infeasible to convert back to the
original value.
• Hashes are not for storing data that needs to be reread but are for proving knowledge of a secret
without the actual secret being revealed.
• Hashes are ideal for verifying passwords. The actual
password is unimportant we just need to have the
user prove that they know the password.
Hashes
• Best practices call for the use of SHA256, SHA384,
SHA512 or higher functions
• Bcrypt is a “Future-Adaptable” open source
hashing algorithm
• Do not use MD5 or SHA1as there are proven
methods for undermining
the hash results.
• SQL Server 2005/2008 only
support MD5 & SHA1,
Denali supports SHA256
SHA384 and SHA512
Demos
• Yay! No more bullet points.
All source code is available on
CodePlex:
http://sqlcrypto.codeplex.com/
References
Laurentiu Christofor: http://blogs.msdn.com/lcris/
Raul Garcia: http://blogs.msdn.com/raulga
Bruce Schneier: http://www.schneier.com/
http://blogs.msdn.com/b/sqlsecurity/archive/2010/06/14
/database-encryption-key-dek-management.aspx
• Cryptography:
•
•
•
•
o http://www.garykessler.net/library/crypto.html
o http://www.cacr.math.uwaterloo.ca/hac/
• BCrypt:
o http://chargen.matasano.com/chargen/2007/9/7/enough-with-the-rainbowtables-what-you-need-to-know-about-s.html
o http://codahale.com/how-to-safely-store-a-password/
o http://derekslager.com/blog/posts/2007/10/bcrypt-dotnet-strong-passwordhashing-for-dotnet-and-mono.ashx
• Demo source:
http://sqlcrypto.codeplex.com
@jkuemerle / joe at kuemerle.com
http://www.speakerrate.com/jkuemerle
Photo Credits
• http://www.flickr.com/photos/wwworks/4612188594
• http://www.flickr.com/photos/joyosity/3358614462
• http://www.flickr.com/photos/jmrosenfeld/31582581
5
• http://www.flickr.com/photos/23258385@N04/22258
09637
• http://www.flickr.com/photos/chelseamcnamara/4
058966236
• http://xkcd.com/538/