Guest Editorial

1 Introduction With the development of multimedia technology and network technology, multimedia services become more and more popular. In nowadays, multimedia information refers to not only text, image, video or audio but also graphics, flash, web, 3D data, etc. Multimedia information is networked in various modes, e.g., fixed network, wireless network, mobile network, etc. Multimedia information may be generated, processed, transmitted, retrievaled, consumed or shared in various environments. Additionally, security becomes an important issue for information networking. During the past decades, many works have been done in multimedia information networking and security. This special issue aims to expose the readership to the latest research results on Multimedia Information Networking and Security, demonstrate pioneer work, investigate novel solutions and discuss the future trends in this field. It is composed of 8 papers, most of which are selected from best papers recommended by international conference - MINES2010, covering the topics of multimedia computing, intelligence, communication, copyright protection, and security. Additionally, all these submissions have been reviewed by at least two reviewers for each paper. 2 The papers in this special issue The first paper, "Code Syntax-Comparison Algorithm based on Type-Redefinition-Preprocessing and Rehash Classification" by B. Cui et al., proposes code comparison technologies for large-scale software plagiarism detection. The first technology is based on type redefinition plagiarism detection, which could detect the level of simple type redefinition, repeating pattern redefinition, and the redefinition of type with pointer. Another one is based on rehash classification, which enhances the node storage structure of the syntax tree, and greatly improves the efficiency. The technologies can be used for software security protection and plagiarism detection. In the second paper, "Software Watermarking Through Obfuscated Interpretation: Implementation and Analysis" by Y. Zeng et al., a software watermarking scheme robust against various attacks including collusion attacks is proposed based on obfuscated interpretation. This scheme spreads the watermark over the entire program by modifying instruction frequencies, in which, the obfuscated interpretation technique is adopted to hide the functionality of a given program and provide an alternative simple way to manipulate the instruction frequencies. Some experimental results are given to show the proposed watermark scheme’s robustness against various attacks. Th