I. Introduction
With the development of computers and communication systems in recent years, how to keep the confidentiality and security of the sensitive data has become the most important issue. In order to prevent secret messages from being used by those unauthorized people, many technologies have been explored, such as encryption, steganography and watermarking. Data hiding is one technology which can hide any secret message or other seemingly innocuous messages in a carrier through steganography [1]. Compared with encryption, it is less likely to attract evildoers’attention, thus securing the data safety [2]. Therefore, to conduct research on transmitting secret message by data hiding to avert malicious attacking and to fulfill a safe transmission has been becoming more and more popular. Carrier can be any medium to convey information, including texts, videos, sound tracks, images [3]–[7] and 3D objects [8]. Hiding process may cause few changes of the above carriers. An evildoer can detect the secret messages via ordinary signal processing and geometric transformation.