Security is becoming one of the most urgent challenges in database research and industry, and the challenge is intensifying due to the enormous popularity of e-business. The authors study database security from a cryptographic point of view. They show how to integrate modern cryptography technology into a relational database management system to solve some major security problems. Our study shows that cryptographic support is an indispensable ingredient for a modern RDBMS to provide a secure environment for storing and processing a huge amount of business data.