About the Author
Kenji Takahashi is the president and CEO of NTT Multimedia Communications Laboratories, Inc. in San Mateo, California. He received his Ph.D. in computer science from Tokyo Institute of Technology. Elisa Bertino is a professor and research director at Purdue University in West Lafayette, Indiana. She holds a Ph.D. in computer science and is a Fellow of the IEEE Computer Society and the Association for Computing Machinery.