公开(公告)号：US11983789B1

公开(公告)日：2024-05-14

申请号：US18412497

申请日：2024-01-13

Applicant: Nanjing Normal University

Inventor： Na Ren ,  Changqing Zhu ,  Yuchen Hu ,  Qianwen Zhou ,  Heyan Wang

IPC: G06T1/00 ,  G06F21/16 ,  G06F21/60

CPC classification number: G06T1/0064 ,  G06F21/16 ,  G06F21/602

Abstract: A generation method of zero watermarking for trajectory data, a detection method of zero watermarking for trajectory data, a generation device of zero watermarking for trajectory data, a detection device of zero watermarking for trajectory data, and a storage medium are provided. The generation method divides a trajectory based on a coordinate system constructed by trajectory feature points of trajectory data into blocks, and then the moment invariants of trajectory in each block are used to construct a watermark sequence, which can achieve copyright protection without modifying the trajectory data. In addition, since the generation method uses moment invariants which can represent overall features of the trajectory to construct the watermark sequence, the generation method has strong stability in the face of common attacks and can resist almost all common types of attacks.

公开(公告)号：US12014440B1

公开(公告)日：2024-06-18

申请号：US18424760

申请日：2024-01-27

Applicant: Nanjing Normal University

Inventor： Na Ren ,  Xuchao Lv ,  Changqing Zhu ,  Qianwen Zhou ,  Heyan Wang

IPC: G06T1/00 ,  G01C21/00

CPC classification number: G06T1/005 ,  G01C21/38 ,  G06T2201/0062 ,  G06T2201/0063 ,  G06T2201/0065 ,  G06T2201/0202

Abstract: A watermarking method for a high-definition map based on invisible characters includes: firstly, establishing mapping relations between invisible characters and bit characters, a space character, and decimal digits; and combining watermark characters with corresponding positions thereof, adding Hamming code into a watermark character sequence, and converting the watermark character sequence into invisible characters to construct a composite watermark character sequence. Before watermark detection, a sequence of elements in map data is scrambled according to logistic chaotic mapping, and then the composite watermark character sequence is embedded according to the scrambled sequence. During watermark detection, the data are preprocessed, a sequence during watermark embedding is obtained, and then watermark information is extracted, errors are corrected, and an error correcting code is removed after correction to obtain final watermark information. According to the watermarking method, watermark embedding and watermark detection can be realized not changing data availability and high-accuracy characteristic.

公开(公告)号：US12174923B1

公开(公告)日：2024-12-24

申请号：US18732644

申请日：2024-06-04

Applicant: The Third Surveying and Mapping Institute of Hunan Province ,  Nanjing Normal University

Inventor： Xingxiang Jiang ,  Qianwen Zhou ,  Changqing Zhu ,  Hua Sun ,  Luanyun Hu ,  Sheng Chen ,  Xi Liu ,  Tan Chen ,  Yujing Liu ,  Na Ren

IPC: G06F21/16 ,  G06F21/60

Abstract: A zero-watermarking method and device for BIM data, and a medium are provided, which relate to the field of watermarking information security technologies. Aiming at existing zero-watermarking method for the BIM data cannot resist primitive attacks, vertical stability of a model is used to construct a mapping relationship between primitive clusters and watermarking bits, calculate norms of primitives in each primitive cluster of the primitive clusters, take positivity and negativity of norm skewness measurement of the primitives as eigenvalues to construct a binary sequence, and performs an XOR process on the binary sequence and an original watermarking sequence to construct the zero-watermarking for the BIM data. Experimental results indicate that the zero-watermarking method has uniqueness, robustness and security.

公开(公告)号：US12131401B1

公开(公告)日：2024-10-29

申请号：US18732548

申请日：2024-06-03

Applicant: Nanjing Normal University

Inventor： Na Ren ,  Yuchen Hu ,  Changqing Zhu ,  Qianwen Zhou

IPC: G06T1/00 ,  G06F21/60

CPC classification number: G06T1/005 ,  G06F21/602 ,  G06T1/0042 ,  G06T2201/0064 ,  G06T2201/0065

Abstract: A dual watermarking method for trajectory data based on robust watermarking and fragile watermarking uses an encryption algorithm to construct robust watermark information, and then a farthest pair of feature points in a minimum convex hull of is set as constant points. Further quantization index modulation technology is used to embed robust watermark information into angles constructed from feature points and constant points. Finally, the angles and distance ratios constructed by trajectory points and constant points are used to group trajectory points. Within each group, spatiotemporal attributes of the trajectory points are taken as fragile watermark bits to be embedded in the distance ratios constructed by the trajectory points. A process of watermark detection is consistent with the embedding of watermark information. Watermarks embedded in the trajectory data based on the dual watermarking method have high robustness against translation, rotation, and scaling attacks.