Himanshu Dwivedi is a leading security expert and researcher. He has published four books, Hacking Exposed: Web 2.0 (McGraw-Hill), Securing Storage (Addison Wesley), Hacker's Challenge 3 (McGraw-Hill), and Implementing SSH (Wiley). A founder of iSEC Partners, Himanshu manages iSEC's product development and engineering, specialized security solutions, and the creation of security testing tools for customers.

Voice Over Internet Protocol (VoIP) networks, the technology used to place phone calls through the Internet, suffer from the same security holes as standard IP networks, as well as new threats specific to telephony. In addition to attacks on network availability and authentication, administrators must contend with eavesdropping, audio injection, Caller ID spoofing, VoIP phishing, and other unique exploits. All of these security holes can result in the leakage of information and in unreliable phone calls. Hacking VoIP reviews the many possible VoIP attacks, and discusses the best defenses against them for both enterprise and home VoIP solutions. Author Himanshu Dwivedi introduces popular security assessment tools, describes the inherent vulnerabilities of common hardware and software packages, and provides the first ever VoIP security audit program. The book covers common enterprise VoIP protocols such as SIP and RTP as well as unique protocols like H.323 and IAX.