Security concerns may arise for companies implementing service-oriented architectures. Users don't have to separately log on to various applications, and each step of a service presents opportunities for a skilled user, authenticated for one area, to access other areas for which he isn't cleared. Shawn Furgason, manager of Web delivery at aerospace and defense contractor Rockwell Collins Inc., knows there are perils to letting the company's ERP systems supply services to outside business partners and customers. To qualify customers to use the portal, Furgason's IT unit checks applicants' names with Rockwell Collins' business units; someone with direct knowledge of an applicant has to sign off on the approval.
"We don't publicly expose our directory of services. We authorize someone to access it on a service-by-service basis," Furgason says. An extra layer of precaution: Each message is intercepted and routed to a Reactivity Inc. XML firewall that makes sure senders are known and authenticated and that messages don't contain hidden commands. Without XML inspection gateways, Rockwell Collins' security team wouldn't let outsiders have access to the company's SOA services, Furgason says.
But service-oriented architectures actually have a security advantage over traditional, monolithic applications running on Windows servers. When an exploit is detected in Windows, there are 100 million servers around the Internet and in businesses that all simultaneously need a patch. Each SOA environment, on the other hand, is a mix of systems, each presenting a hurdle for the would-be hacker, says James Whittaker, professor of computer science at the Florida Institute of Technology and founder of security firm Security Innovation Inc. "SOA takes the patching problem away," he says. "That's a massive advantage in maintaining a quality [safe] environment."