TEAM Zarate Tarrani Notes From the Field

A Challenge. In my last entry I didn't really take Linda's spot - XLM and Oracle (or any database) have a natural affinity. XML is the magic. You can stuff the results of a SQL query into a DTD, which is the stuff of application and database integration. However, there are also security challenges. The topic of this entry is XML and database security, and is based on two excellent books I recently finished reading.

The first book is Translucent Databases. This book contains an innovative and viable approach to securing databases, and one that I've not encountered anywhere else. In a nutshell the author provides techniques, based on standard SQL and Java, for securing sensitive data without restricting general access of less sensitive data to authorized users. The core of this approach is based on encryption and one-way functions, including PKI and secure hashing, and accepted authentication techniques such as digital signatures.

What makes this book unique is that while it's based on solid theoretical ground, the material is practical. As the techniques are discussed they are illustrated by 15 different scenarios, all of which contain problems faced by e-commerce, HIPAA and other high security environments, and code examples that show how to solve the problems. I like the way the author shows how to implement his solutions in common database environments (PostgreSQL, MySQL and Oracle - the approach should also work in the MS SQL Server environment). As I read this book I saw interesting possibilities for implementing role-based access controls and securing against SQL-based statistical attacks using the author's approach.

This book is essential reading for DBAs, system architects and IT security professionals, especially those in healthcare who are struggling with meeting HIPAA requirements, and in e-commerce who are challenged by protecting credit card and account information. This book shows the DBA how to secure his or her database, and the system architects and security professionals what is possible using SQL and Java. The book also has an associated web site which is supposed to have soft copies of all of the source code contained in the book. As of this entry the link to the source code is on the site, but the code itself is not yet available. When it is the value of this book will increase even more because of the time it will save by not having to manually create the code from scratch.

If you are new to the cryptographic techniques introduced in this book I recommend Cryptography Decrypted by H. X. Mel and Doris M. Baker, which is one of the best introductions to this complex subject. I also recommend reading Secrets and Lies: Digital Security in a Networked World by Bruce Schneier, which covers the technical, organizational and social aspects of security and gives a clear description of the technical underpinnings discussed in this book.

The second book is XML Security. Given the fact that XML is a key component of web services, and extensively used in e-commerce and enterprise applications integration, this book addresses a genuinely important topic. For one reason, XML is text-based and can expose proprietary information, which is a vulnerability for competitive intelligence specialists and corporate spying.

Before going into what the book contains it's important to know that much of the material is based on RSA's view of the security. This isn't a criticism, but an up-front statement of fact because if you're looking for a book that is 100% vendor neutral you are going to have to wait until one is written - this is the only book I know of that is solely about XML security.

The book starts with primers on security and XML to set the context. It then covers, in succession, digital signatures (chapters 4, 5 and 6), and XML encryption. These chapters are consistent with work and specifications produced by XML Signature WG (joint the Working Group IETF and W3C for digital signatures) and the W3C working group for XML Encryption.

Chapter 8 is specific to RSA products. It shows how to implement XML encryption using RSA BSAFE© Cert-J, which can be downloaded in a trial version from RSA's website. Chapter 9 covers XML key management specification, which are consistent with the W3C working group's specifications, and how XML security relates to web services.

Despite the slight bias towards RSA this book is an invaluable reference. It provides an in-depth discussion of major security issues, as well as how they are being addressed by the W3C. It goes without saying that anyone who is responsible for system architecture, design and/or security should carefully read this book.