People who use public WiFi to make iPhone calls or conduct video conferences take heed: It just got a lot easier to monitor your conversations in real time.

At a talk scheduled for Saturday at the Toorcon hacker conference in San Diego, two security researchers plan to show the latest advances in the open-source UCSniff tool for penetrating voice-over-internet-protocol systems. With a few clicks of a mouse, they will eavesdrop on a call between two audience members using popular iPhone applications that route the calls over the conference network.

For more than a year, UCSniff has provided everything a hacker needs to plug a laptop into a network and within seconds begin intercepting VoIP transmissions. But until now, the program has allowed eavesdroppers to reassemble the conversations only after they were concluded, a limitation that was far from the elite bugging capabilities shown in Mission Impossible and other spy thrillers.

"As the private call is in progress, we can see and hear what is happening," said Jason Ostrom, a developer of UCSniff and director of Viper Labs, the research arm of security firm Sipera Systems. "There's real-time violation of confidentiality."

In addition to monitoring voice conversations as they happen, UCSniff can also bug video conferences in real time. Ostrom said he and fellow Viper Labs researcher Arjun Sambamoorthy plan to show those capabilities at Toorcon as well.

With the proliferation of iPhones and other smartphones, plenty of businesses and individuals have sought to save money on roaming charges by routing calls over the internet instead of over carrier networks. Adam Boone, a vice president at Sipera, said one large, unnamed client logs more than 1 million minutes per month in such VoIP calls.

The problem, he added, is that many of the iPhone apps for VoIP calls don't provide encryption capabilities, making the conversations ripe for eavesdropping. (Sipera plans to unveil a new product to protect such users next week).

No doubt, traffic traveling over unsecured networks has always been vulnerable to snoops. UCSniff just streamlines their work by bundling a hodgepodge of tools that previously were only available piecemeal.

It turns any laptop into a man-in-the-middle node. A VLAN hopper then traverses the virtual local area network until it accesses the part that carries VoIP calls. UCSniff automatically injects spoofed address resolution protocol packets into the network, allowing all voice and video traffic to be routed to the laptop.

Ostrom said the tool is designed to help penetration testers quickly assess the security of clients' networks and to help security providers to stay abreast of the latest attacks.

"If we can do this, there are many, many people out there who can do this. It's not rocket science," he said. "The end game here is to help them improve their products, to know what types of attacks can happen so they can build security features into their products." ®