Research On Methods Of Hiding Information In Flash Animation

Information hiding is a kind of technology that hide secret messages inside ofimage, audio, text, video, webpage etc. To a casual observer inspecting these medium,the messages are invisible. This tech is widely used in electronic commerce, copyrightprotection, covert communication. At the present stage, information hiding methodsare mainly based on the carrier format of text, image and audio, those on flash are justbeginning. Flash, as a common video format of network, has small size and wideapplicability, thus the study methods of hiding information in the flash animation is offar-reaching applications prospect and significance.This paper aims to study how to hide information using flash animation as acarrier. Existing research in this area is relatively little, mainly relied on the read rulelimits of flash player for some tags that SWF file format specification states. Forexample, the article "Steganographic Techniques for Hiding Data in SWF Files"surveys several algorithms embedding hidden information in a SWF file. Thetechniques include appending data to an SWF file, adding an extra Metadata tag,creating a custom Definition tag, and replacing fill bits with hidden data.This main work of this paper includes following several parts:1. Study the Flashanimation format, play policy and the existing application occasions;2. Analysisseveral existing methods of flash animation hiding technique, and evaluate them inhiding capacity, Confidentiality, and display effect to the flash after embedding secretinformation;3. Proposes two kinds of hiding method in flash animation: one is basedon flash animation label property and has implemented by C++language. Thismethod modifies the depth of a layer object values while guaranteeing the depth order doesn’t been changed to achieve the purpose of hiding. The second method is basedon the interaction and event flow mechanism in script language of flash animation. Byexperiments, we know the two methods make no change at the display effect afterembedding secret data, compared to the source file, besides, can achieve aconsiderable confidentiality. Of course, they also have some flaws, such as simple andlack of appropriate assessment criteria. At the end of the article, summarizes thelessons learned and points in this work, and come up with the ideas for improving andthe prospect for the future.