Research On The Theory And Method For Manufacturing Data Security Authentication

With the fast development of the computer-aided design(CAD)and computer-aided manufacturing(CAM),the manufacturing industry has dramatically improved production efficiency through informatization.However,it also faces a series of security issues,such as product design drawings may be maliciously tampered with,the drawings stored on the cloud may be leaked out,and the 3D printed objects may be forged.In order to solve the above problems and prevent the violation of the copyrights of producers,adequate protection of manufacturing data has received extensive attention.In this paper,we focus on four aspects:the reversible watermarking,integrity authentication for 2D vector graphics,the reversible data hiding in encrypted 2D vector graphics,and the authentication for 3D printed objects.The main contributions are summaried as follows:1.A distortion-free 2D vector reversible watermarking based on the bionic spider web is proposed for tampers localization.Aiming to solve the problems in existing authentication methods that the watermark is not robust enough due to the dependence on the file stream order and introducing too much distortion by moving vertices,the geometric correlated watermark is constructed by adding vertices into entities,and a reversible watermark algorithm based on bionic spider web is designed.During the embedding stage,two different webs are constructed based on the convex hull of the graphics and a key.First,some vertices are added to where the first web intersects with the graphics.After that,the numbers of times each cobweb of the second web intersects the entities are recorded.Under the condition that the convex hull is invariant,the tampers can be localized with the entity level precision by reconstructing the same spider webs and analyzing its intersection state with the graphics.The experimental results and analyses show that,compared to the other algorithms,as the proposed one does not change the shape of entities at all,it has the best performance of imperceptibility.Besides,it is robust against the operations that do not change the topology of the graphics,such as rotation,scaling,translation(RST)or entity rearrangement.2.A low distortion reversible watermarking for 2D engineering graphics is presented.To reduce the distortion of traditional partitions,a novel method that partitions every square region into 2~n nesting sub-regions is firstly investigated.The watermark is embedded by mapping the vertex in the original region to its corresponding sub-region,and it is extracted according to the location of the mapped vertex.Meanwhile,the original location of the vertex can be restored by inverse mapping.Furthermore,by constructing a new coordinate system with the reference vertices,the RST semi-fragility of the watermarking can be achieved.Experimental results and analysis show that the imperceptibility of the proposed watermarking is significantly improved10%compared with other similar algorithms under the same conditionsm,while the watermarking also has good performance in terms of capacity and semi-fragility.3.A semi-fragile reversible watermarking for authenticating 2D engineering graphics based on improved region nesting method is constructed.According to a further investigation of the region nesting(RN)partition,it is found that the original vertex and its mapped ones cannot be guaranteed to be on the same line.Based on this,an improved region nesting partition(IRN)is put forward,which can reduce at least 15%distortion compared to RN.What is more,by generating and embedding a short hash of the neighboring geometric features for every vertex,the vertex level tamper localization precision can be achieved.Last but not least,its semi-fragility can be achieved by constructing a new coordinate system with geometric features.The experiment results show that the proposed method can strike a good balance among imperceptibility,semi-fragility and tamper localization precision without file size expansion.4.A real number reversible mapping model based reversible data hiding(RDH)method in encrypted 2D vector graphics is proposed.For hiding data into the encrypted 2D vector graphics,a reversible mapping model for real numbers is first built.It maps the points in R~n to 2~s non-intersecting subsets in R~n,which guarantees that s bits can be embedded into each real number.Based on this model,an RDH scheme in encrypted 2D vector graphics is put forward.In the scheme,a user encrypts a 2D engineering graphics and uploads it to the cloud,and then the cloud service provider(CSP)can perform information hiding,extraction,and even recover the encrypted 2D vector graphics.For the authorized user,it can acquire the recovered 2D vector graphics from the cloud and obtain its original version after decryption.While for an unauthorized user,he can only acquire the encrypted 2D vector graphics with the hidden message,and only an approximate 2D vector graphics can be obtained even he knows the decryption key but does not know the hiding key.Experimental results and analysis show that it can strike a good balance between security,distortion,and capacity.5.An authentication framework for 3D printed objects is presented.With the increasing use of 3D printing technology,many consumer products are now getting manufactured by 3D printers.However,illegal copies of such products printed by a counterfeiter are becoming a problem for authentic manufacturers.To counter this problem,3DPS,an improved printing signature for 3D printed objects based on the improved equipment distortion model,is proposed for authentication in this paper.In this method,a specific hole is added to the non-critical flat portion of the 3D model,and the 3DPS is constructed from the contour of this hole with a hand-held microscope.After that,by computing the difference between the extracted 3DPS and the registered ones,the authenticity of products can be verified.Compared to our previous work,the equipment distortion model and the 3DPS's construction method are improved,and the threshold can be calculated directly rather than determined by experience.Theoretical analysis and experimental results show that the 3DPS not only can effectively authenticate 3D printed objects with high accuracy but is also robust,secure,and cheap.