Hiding Information in 3D Printed Objects by Forming Fine Cavities inside Objects

Kazutake Uehira, Satoru Baba, Masahiro Suzuki, Piyarat Silapasuphakornwong, Hideyuki Torii, Youichi Takashima Kanagawa Institute of Technology 1030 Shimo-ogino, Atsugi, Japan uehira@nw.kanagawa-it.ac.jp; msuzuki@ctr.kanagawa-it.ac.jp; silpiyarat@gmail.com; torii@nw.kanagawa-it.ac.jp NTT Service Evolution Laboratories/ Nippon Telegraph and Telephone Corporation 1-1 Hikarinoka, Yokosuka, Japan takashima.youichi@lab.ntt.co.jp