Imperva was chosen over rival Teros Inc. "We were specifically interested in how each product broke down SSL sessions," Ewing said. Imperva, he said, did it faster.

Rolled out in just half a day, the firewall was also programmed to learn to differentiate between normal and suspicious traffic. That process took less than a week. The firewall also offers application-level security. For instance, it can alert managers immediately if it notices that an application wasn't coded using best security practices.

The database gateway, meanwhile, is being used to protect several hundred gigabytes of customer data stored on a number of databases, including Oracle, SQL Server and Informix, against attacks such as SQL injections aimed at harvesting data. That will augment the full encryption of all that data, a process Accor hopes to complete by year's end.

Accor bought two SecureSphere appliances for US$50,000 each, and they work together to provide monitoring and auditing of database activity, which will help Accor comply with Peripheral Component Interconnect data security standards as demanded by credit card vendors.

Imperva claims to have more than 100 customers, including Israel's Ministry of Defense, BlueCross BlueShield of Tennessee Inc., Korea Life Insurance Association and the Houston Municipal Employees Pension System.