Autocad Electronic Signature Plug-in Design And Implementation

AutoCAD software is now widely used in the industry design, and the efficiency in design has been greatly improved with it. However, with much convenience AutoCAD brings us, it also gives rise to many new security problems. When an AutoCAD drawing is spreading in a crowd, all the viewers can copy and modify it easily. These behaviors are unrestricted, so it is very universal for the information leaking to some people unauthorized, and cause dispute on copyright. As an important technology in protecting electronic documents, electronic seal has attracted more and more researchers. In this thesis, we intend to use electronic seal to resolve the security problems in AutoCAD application, including the data integrity, anti-denying and so on.AutoCAD drawings are designed to store vector graphics, so we can't apply techniques which used to protect bitmap images to them directly, and the research in vector graphics security is still unsatisfied. Furthermore, AutoCAD's native file DWG isn't a public data format, this make it more difficult to protect AutoCAD drawings. According to the security requirements, this thesis analyses the insufficient of the existing resolutions. We focus our work on several key security technologies, propose a consummate resolution of electronic seal and realize the plug-in.This thesis mainly concerns on the following problems: (a) The production of electronic seal and its security. (b) Extraction and use of the DWG drawing format. (c) How to add extra data into AutoCAD vector graphics. Based on the"digital signature"and union with digital certificates, we design a consummate process for signature and verification. Also, our work on the three above problems could satisfy the requirement of a consummate sign process. We choose ObjectARX as our re-development tool of AutoCAD. For it shares the same address space with AutoCAD, so the plug-in has a high efficiency and the user won't feel delay obviously.The plug-in we design in the thesis has an excellent performance, the fact prove that this resolution can satisfy the security requirements of AutoCAD drawings such as data integrity, anti-denying, status authentication and so on. Also, electronic seal derived the character of tradition seal, visual and authoritative.