The utilisation of 3D models in low-cost devices, such as the internet of things, virtual reality, and augmented reality, is expanding. The challenge lies in the lack of lightweight solutions for verifying the authenticity of models in the graphics library transmission format (glTF) on devices with limited resources. The glTF standard, which allows storage in glb format, is the leading standard for representing 3D assets. Despite its popularity, research on watermarking glTF models remains limited. This paper proposes a novel method for authenticating 3D models in glb format based on fragile watermarking. Additionally, an analysis was conducted to determine the impact of embedding the watermark in vertex attributes other than position on the integrity and visual quality of the model. The methodology is as follows: (1) embedding the watermark, (2) applying model modification or omitting it, and (3) verifying authenticity based on the recovered watermark. The proposed algorithm attaches a 512-bit hash-based message authentication code (HMAC) to a 3D model using the least significant bits (LSBs) modification method. The use of HMAC and LSBs has resulted in a computationally efficient algorithm that can be implemented in low-cost devices.

Three-dimensional assets have evolved into a pivotal element within the domains of electronic entertainment, medicine, and engineering. Unfortunately, 3D models comprise voluminous data, which is not readily amenable to analysis or to the application of simple algorithms. This study thoroughly analyses the usability of the classical Isolation Forest (IF) method as a novel instrument for 3D mesh analysis. Given the atypical nature of 3D model data, it was necessary to obtain the special multidimensional feature vector (FV) associated with each vertex. The FV codes information regarding the local curvature of the surface in the vicinity of the vertex. As demonstrated by experimental studies, the IF analysis is capable of detecting geometrical details, areas of dense, complex geometry, strong bends, and folds in the mesh. This finding indicates a significant steganographic potential, which prompted the authors to employ research findings in the domain of 3D mesh watermarking as a practical illustration. Thanks to IF, a new steganographic method was developed that is characterised by higher transparency, achieved by hiding data in areas of complex geometry. The study proves the high potential of IF for analysing and watermarking 3D models, representing a meaningful step toward broader applications of IF in this field.