Multimodal dynamic haptic encryption method, haptic encryption skin, system and applications

Abstract

The application provides a multi-modal dynamic tactile encryption method, a tactile encryption skin, a system and an application, which comprises the following steps: a dynamic tactile force acts on a tactile encryption epidermis, image data of an initial state of the tactile encryption epidermis and an image data generated in a dynamic tactile action process are collected through a tactile encryption subcutaneous tissue; based on the image data, a position cell tensor, a velocity tensor and a depth tensor generated before and after the encryption epidermis granular layer is subjected to a tactile stimulation are obtained; based on the position cell tensor, the velocity tensor and the depth tensor, a double-modal dynamic tactile feature or a multi-modal dynamic tactile feature based on a dynamic force-velocity-depth coupling is constructed; and the double-modal dynamic tactile feature or the multi-modal dynamic tactile feature is subjected to multi-level standard encryption based on a self-defined initial key to obtain a final dynamic multi-modal tactile process encryption result. The application has high specificity, which includes spatial and temporal features; the encryption process is dynamic, contains the whole process of biological tactile action, and has high reliability.

Description

Technical Field

[0001] This invention relates to the field of tactile sensor technology, specifically to a multimodal dynamic tactile encryption method, tactile encryption skin, system, and application. Background Technology

[0002] With the rapid development of the information age, the security of personal information of electronic product users is crucial to everyone's privacy and vital interests. Using secure, reliable, and unclonable biometric encryption technologies is a critical aspect that must be considered in the design and manufacturing of electronic products. Currently, common biometric encryption technologies mainly include the following six types: static recognition (fingerprint, iris, vein) and dynamic recognition (face, gesture, and voice). On the one hand, fingerprints can be easily copied by tools such as photosensitive stamping; although the iris of the human eye has consistency, according to current recognition principles, iris recognition can be cracked through focused beam imaging and black-and-white laser printing; currently, the more secure vein recognition encrypts the distribution of veins with blood flow in a living body, but the permanence of vein features has not yet been proven. On the other hand, facial, gesture, and voice recognition involve faces, movements, and voices, all of which are explicit external features that are easily learned and imitated from a third-person perspective. Therefore, they require high environmental security; otherwise, they are easily spied on by hidden cameras, leading to leaks. Furthermore, some researchers have proposed a multi-verification scheme combining static and dynamic methods, combining the above single-modal biometric technologies to improve biometric security. However, in penetration tests conducted by security engineers, the above methods can be easily cracked within minutes. Therefore, it is urgently needed to invent a new biometric identification technology that is difficult to forge, highly permanent, and hard to steal.

[0003] Biometric identification technology is currently widely used for user identification on mobile devices, with fingerprint and facial recognition being the most mature methods. In addition, other sensor-based data encryption and authentication methods exist. Joy Bose et al., in their paper "Encryption In Mobile Devices Using Sensors," proposed obtaining three-dimensional gesture information by combining hand gestures such as shaking the phone with accelerometer readings; establishing a fixed mapping relationship between two-dimensional coordinate changes of basic touch gestures (such as swiping, long-pressing, and panning) and specified information; and encoding and encrypting data using GPS or optical sensors with latitude, longitude, or ambient light. However, these encryption methods are highly dependent on the device's sensor readings and cannot be directly linked to the user's own characteristics, still posing a risk of cloning.

[0004] In other fields, the application of biometric identification technology remains relatively limited. For example, handwritten signatures, as the most common form of identification, rely primarily on traditional image recognition technology for recognition, resulting in poor anti-counterfeiting capabilities and susceptibility to theft. Furthermore, the creation of electronic art and similar works currently lacks feasible encryption methods for the creative process. Reliance is limited to recording the creation process via video or comparing images of the final product. Therefore, there is a lack of effective technical means to protect the personal artistic value of creators, particularly the absence of biometric encryption technology linked to the creator. Consequently, how to utilize a novel, highly secure biometric encryption method for anti-counterfeiting of handwritten signatures and electronic art has become a promising emerging application area worthy of in-depth research.

[0005] Touch is the most basic and widely used sensory system in humans. Nerve cells in every inch of human skin receive signals from external forces, surface shapes, and materials. However, touch is also a major sense with relatively limited research and application because its complex mechanoreceptors are difficult to mimic using electronic skin. Thus, human touch is a unique biological sense at the cellular level, possessing high resolution but also strong specificity, making it difficult to replicate through imitation. Currently, there are no research reports on tactile encryption. Therefore, research on tactile encryption holds promise for widespread application in the Internet of Things (IoT) and body area networks (BAND). Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a multimodal dynamic tactile encryption method, tactile encryption skin, system, and application. It utilizes the user's bio-tactile senses to generate multimodal tactile feature signals of "force-velocity-depth" on the tactile encryption skin, performing dynamic encryption throughout the entire process. This achieves an unclonable biometric encryption method, which can be applied to information encryption of wearable devices in the Internet of Things and Body Area Networks.

[0007] According to one aspect of the present invention, a multimodal dynamic haptic encryption method is provided, comprising:

[0008] Dynamic tactile sensation is applied to the tactilely encrypted skin;

[0009] Image data generated by the tactilely encrypted subcutaneous tissue during the initial state and dynamic tactile action of the tactilely encrypted epidermis are collected.

[0010] Based on the image data, the position cell tensor, velocity tensor, and depth tensor of the encrypted epidermal granular layer before and after being subjected to tactile stimulation are obtained.

[0011] Based on the position cell tensor, velocity tensor, and depth tensor, a bimodal dynamic tactile feature or a multimodal dynamic tactile feature based on dynamic force-velocity-depth coupling is constructed.

[0012] The bimodal dynamic tactile features or multimodal dynamic tactile features are subjected to multi-level standard encryption based on a custom initial key to obtain the final dynamic multimodal tactile process encryption result.

[0013] Preferably, the tactile action includes continuous contact action, discontinuous contact action, or a combination of continuous and discontinuous action.

[0014] Preferably, the process of acquiring the image data includes:

[0015] The image sensor in the tactile encryption subcutaneous tissue is used to acquire tactile encryption epidermal images of each frame throughout the entire process of dynamic tactile action from the initial state to the final state.

[0016] By pre-specifying the time interval for image acquisition t, acquire tactile encrypted skin images at multiple time points, with a total number of n images.

[0017] Preferably, the process of obtaining the position cell tensor is as follows:

[0018] The acquired tactile encrypted epidermal images were preprocessed, and the position cell matrix of the encrypted epidermal granular layer in the tactile encrypted epidermal epidermis under the initial no tactile action was marked as P1;

[0019] After a tactile sensation is applied, the displacement change of each encrypted epidermal particle is tracked, including the direction and length of the displacement. The position cell matrix of that encrypted epidermal particle layer is updated in each frame until the final state of the tactile sensation is reached, resulting in the position cell matrix P of the last encrypted epidermal particle layer. n ;

[0020] Based on the changes in the positional cell matrix of the encrypted epidermal particles between adjacent image frames, the type, direction, and magnitude of the tactile force applied can be deduced.

[0021] All the position cell matrices together form the position cell tensor P. all ;

[0022] The process of obtaining the velocity tensor is as follows:

[0023] The time interval between two specified tactile encrypted skin image frames is calculated. T, calculate the difference in the position cell matrix of a specified encrypted epidermal particle in two frames. P;

[0024] Through the difference of the location cell matrix P divided by the time interval T, the velocity S of the specified encrypted skin particles during the tactile action in these two frames is obtained;

[0025] By specifying two frames of tactile encrypted epidermal images multiple times, the velocity matrix of different encrypted epidermal particles in multiple stages of dynamic tactile process is obtained.

[0026] All velocity matrices together form the velocity tensor S. all ;

[0027] The process of obtaining the depth tensor is as follows:

[0028] Ambient light can be adjusted by changing the position, type, or intensity of the light source.

[0029] The image sensor in the tactile encryption subcutaneous tissue captures images of different surface morphologies reflected by the encryption epidermal reflection layer in the tactile encryption epidermis under different ambient light conditions, when subjected to tactile action.

[0030] The depth matrix H of the encrypted epidermal particles in each frame is obtained using a photometric stereo algorithm;

[0031] All the depth matrices together form the depth tensor H. all .

[0032] Preferably, the process of acquiring the dual-modal dynamic tactile features is as follows:

[0033] Based on the position cell matrix P, velocity matrix S, and depth matrix H, two modalities are selected for coupling to obtain the dual-modal dynamic tactile features T of the tactile encrypted epidermal image. DBL :T DBL =f(P,S) or T DBL =f(P,H) or T DBL =f(S,H);

[0034] The process of acquiring the multimodal dynamic tactile features is as follows:

[0035] By fully coupling the three modalities of "force-velocity-depth", multimodal dynamic tactile features T are obtained. TRI :T TRI =f(P,S,H).

[0036] Preferably, f is a linear function or a nonlinear function, wherein the nonlinear function includes exponential functions and power functions.

[0037] Preferably, the dual-modal dynamic haptic features or multi-modal dynamic haptic features are subjected to multi-level standard encryption based on a custom initial key to obtain the final dynamic multi-modal haptic process encryption result, including:

[0038] Specify a standard encryption method;

[0039] The bimodal or multimodal dynamic tactile features are preprocessed into the data format required by the standard encryption method.

[0040] Customize the initial key and preprocess it into the data format required by the specified standard encryption method;

[0041] The preprocessed custom initial key and the preprocessed bimodal or multimodal dynamic haptic feature T1 of the first frame image are encrypted according to the standard encryption method to obtain the first level ciphertext;

[0042] The first-level ciphertext is used as a new key and encrypted with the bimodal or multimodal dynamic tactile feature T2 of the preprocessed second frame image according to the standard encryption method to obtain the key for the next level, and so on, until the nth level ciphertext is generated.

[0043] The nth level ciphertext is the final encrypted result of the entire dynamic multimodal haptic process.

[0044] According to a second aspect of the present invention, a tactile encryption skin implementing the above-described multimodal dynamic tactile encryption method is provided, comprising:

[0045] A tactile encrypted skin, located on top, undergoes morphological changes under the influence of external dynamic tactile stimulation;

[0046] Tactile encryption subcutaneous tissue, located beneath the tactile encryption skin, captures images of morphological changes in the tactile encryption epidermis;

[0047] A tactile encryption framework that provides fixed support for the tactile encryption epidermis and tactile encryption subcutaneous tissue.

[0048] Preferably, the tactile encryption skin comprises:

[0049] An encrypted elastic skin layer, wherein the encrypted elastic skin layer is a transparent layer and is located at the bottom layer;

[0050] An encrypted outer skin particle layer is embedded within the encrypted outer skin elastic layer. The particle layer contains a number of particles, which are obtained by doping microparticles or printing markers. The encrypted outer skin particle layer can be configured as a single layer or multiple layers, wherein the particles in different layers are staggered and do not obstruct each other.

[0051] An encrypted epidermal reflection layer is located above the encrypted epidermal granule layer and has a reflective function;

[0052] An encrypted skin wear-resistant layer is disposed above the encrypted skin reflection layer to reduce wear on the encrypted skin reflection layer during contact use;

[0053] When dynamic tactile sensation is applied to the tactile encrypted skin, the encrypted skin reflection layer retains the surface morphology of the contact surface without damage due to the reflection effect. The particles in the encrypted skin particle layer will generate corresponding displacement with the external force. The encrypted skin elastic layer allows the particles in the encrypted skin particle layer to undergo depth changes.

[0054] The tactile encryption subcutaneous tissue includes:

[0055] An image sensor that collects and receives light rays converged by a metasurface lens and converts the light signals into electrical signals;

[0056] A metasurface lens is used to capture images of the tactile encrypted skin in a planar form. The images of surface morphology changes and three-dimensional displacement field changes generated by the image layer and the granular layer of the encrypted skin after being subjected to biological tactile action are converged onto the image sensor. The planar metasurface lens is used to reduce the overall thickness of the tactile encrypted skin.

[0057] A digital signal processing chip, which processes and transmits the electrical signals of the image sensor;

[0058] A light source, used to illuminate the tactilely encrypted skin;

[0059] The medium of the tactile encryption skeleton is air or a transparent material with a specified refractive index.

[0060] According to a third aspect of the present invention, a tactile encryption system is provided, which employs the above-described multimodal dynamic tactile encryption method to encrypt the tactile signal process generated by the handwriting on the substrate of the tactile encrypted skin as a handwritten signature or electronic drawing.

[0061] According to a fourth aspect of the present invention, an Internet of Things (IoT) command encryption method is provided, comprising:

[0062] Define a custom tactile motion;

[0063] Based on this tactile action, the above-mentioned multimodal dynamic tactile encryption method is used to obtain the corresponding multimodal dynamic tactile features. After multiple rounds of encryption with the unencrypted IoT command, a brand new command is finally formed.

[0064] The new commands allow for remote control of IoT terminal devices via the cloud.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] The multimodal dynamic tactile encryption method in this invention collects multimodal bio-tactile signals that exhibit a dynamic relationship with both application time and space. Specifically, the dynamic trajectory of the tactile sensation leaves surface morphology variations at different locations and depths within the encrypted epidermal elastic layer, thus demonstrating the three-dimensional spatial characteristics of the tactile signal—namely, the direction and depth of multi-axial forces within the multimodal tactile signal. The encryption process encompasses the entire process of applying bio-tactile sensation to the tactile encryption epidermis, collecting not only static tactile sensation but also the bio-tactile signals along the entire dynamic trajectory of the tactile sensation. Therefore, this dynamic bio-tactile signal possesses both temporal and spatial characteristics, resulting in a higher feature dimension in the encryption source generation process compared to traditional static encryption methods.

[0067] The tactile encryption skin and multimodal dynamic tactile encryption method in this invention fully consider the individual differences in biological touch and the differences between different tactile processes. Its encryption is based on changes in the encrypted epidermal granular layer. Therefore, the mechanical, velocity, and depth changes during the tactile process refer to the vector displacement of the encrypted epidermal granular layer caused by tactile action. The correspondence between the vector displacement and the force (including the magnitude and direction of the force) of the encrypted epidermal granular layer can be extracted using standard mechanical calibration equipment. The correspondence between the depth change of the encrypted epidermal granular layer within the encrypted epidermal elastic layer and the force can be obtained using a photometric stereo algorithm. This method is more reliable than traditional, easily replicated biometric encryption technologies. It is expected to overcome the shortcomings of current traditional biometric encryption technologies, creating a more secure, reliable, and easy-to-use encryption technology in the Internet of Things and body area networks, better protecting users' information and property security.

[0068] The tactile encrypted skin in this embodiment of the invention can collect multimodal features during the dynamic tactile process, providing an accurate data foundation for subsequent encryption and improving the reliability of the encryption technology. Its simple structural design allows for application in multiple scenarios and demonstrates strong applicability. Attached Figure Description

[0069] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0070] Figure 1 This is a flowchart of a multimodal dynamic tactile encryption method according to an embodiment of the present invention;

[0071] Figure 2 This is a framework diagram of a multimodal dynamic tactile encryption method according to an embodiment of the present invention;

[0072] Figure 3 This is a schematic diagram of the acquisition of various tensors in the tactile encryption method of the present invention. (a) The figure shows the position cell matrix P1 to P of the encrypted epidermal particles. n And the position cell tensor P, which is composed of all the position cell matrices. all (a) Schematic diagram; (b) The velocity matrix S of the densified epidermal particles. 1to2 To S (n-1) to n , and the velocity tensor S composed of all the velocity matrices all (c) The diagram shows the depth matrix H1 to H of the encrypted epidermal particles. n And the depth tensor H composed of all the depth matrices all A schematic diagram;

[0073] Figure 4 Figure 1 is a schematic diagram of the structure of the tactile encrypted skin of the present invention. (a) Figure 2 is a schematic diagram of the structure of the tactile encrypted skin of the present invention: tactile encrypted epidermis, tactile encrypted skeleton and tactile encrypted subcutaneous tissue; (b) Figure 3 is a schematic diagram of the structure of the tactile encrypted epidermis of the present invention: encrypted epidermal elastic layer 101, encrypted epidermal granular layer 102, encrypted epidermal reflection layer 103 and encrypted epidermal wear-resistant layer 104.

[0074] Figure 5 This is a schematic diagram of an encryption system based on tactile encrypted skin and a multimodal dynamic tactile encryption method according to embodiments of the present invention;

[0075] Figure 6 This is the relationship between the magnitude of the force and the vector length of the tactile encrypted skin under the action of normal force in an embodiment of the present invention, with the unit being the pixel length of each frame (px / frame).

[0076] Figure 7 The following is a schematic diagram of dynamic tactile feedback based on an embodiment of the present invention: (a) Figure shows a dynamic tactile electronic signature; (b) Figure shows the effect of tactile encryption and the ciphertext during the artwork creation process.

[0077] Figure 8 The IoT tactile encryption commands based on the embodiments of the present invention have the advantages of preventing hacker attacks and preventing eavesdropping;

[0078] Figure 9 This invention relates to an embedded smart tactile encrypted clothing based on tactile encrypted skin, which can wirelessly control the opening of a safe based on the user's tactile signals. Detailed Implementation

[0079] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0080] See Figure 1 and Figure 2 This invention provides an embodiment of a multimodal dynamic tactile encryption method, the process of which is as follows:

[0081] S100, dynamic tactile action is applied to the tactile densified epidermis, the tactile action is a continuous contact action, a non-continuous contact action, or a combination of continuous and non-continuous actions;

[0082] S200 collects image change data of the tactile encrypted subcutaneous tissue through tactile encryption, which is generated during external tactile contact.

[0083] S300, based on image data, obtains the position cell tensor, velocity tensor and depth tensor of the encrypted epidermal granular layer before and after being stimulated by touch.

[0084] S400, based on position cell tensors, velocity tensors, and depth tensors, constructs a bimodal dynamic tactile feature T based on dynamic force-velocity-depth coupling. DBL or multimodal dynamic tactile features T TRI ;

[0085] S500, for dual-modal dynamic tactile features T DBL or multimodal dynamic tactile features T TRI Multi-level standard encryption based on a custom initial key is performed to obtain the final dynamic multimodal haptic process encryption result.

[0086] In this embodiment, the dynamic tactile encryption method encompasses the entire process of applying bio-tactile sensation to the tactile encryption surface. It not only captures the static tactile action but also the bio-tactile signals along the dynamic trajectory of the entire tactile sensation. The dynamic bio-tactile signals possess both temporal and spatial characteristics, giving the encryption source generation process of this method a higher feature dimension than traditional static encryption methods.

[0087] In a preferred embodiment of the present invention, in step S200, an image sensor in the tactilely encrypted subcutaneous tissue is used to acquire tactilely encrypted epidermal images of each frame throughout the entire process of dynamic tactile action from the initial state to the final state. The time interval for acquiring the images is pre-specified. t, thus obtaining n tactile encrypted epidermal images. In a preferred embodiment, the time interval for acquiring images is... The time interval was 0.1 seconds, and dynamic tactile changes were collected over a period of 4 seconds, resulting in 40 tactile encrypted epidermal images.

[0088] In a preferred embodiment of the present invention, S300 is implemented as follows:

[0089] S301, preprocesses the tactile encrypted epidermal image acquired by S200, including noise reduction and grayscale conversion;

[0090] S302, such as Figure 3 As shown in Figure (a), the position cell matrix of the encrypted epidermal particle layer in the tactile encrypted epidermis under the initial state without tactile action is labeled as P1. After being subjected to tactile action, the displacement change of each encrypted epidermal particle can be tracked by optical flow, including the direction and length of the displacement, thereby updating the position cell matrix of the encrypted epidermal particle layer in each frame until the final state of the tactile action, obtaining the position cell matrix P of the encrypted epidermal particle layer in the last frame. n Based on the changes in the position cell matrix of the encrypted epidermal particles between adjacent image frames, the type (normal force, shear force, or torsional force) and direction of the tactile force, as well as the magnitude of the force, can be deduced. All position cell matrices together form the position cell tensor P. all Each element of the position cell matrix contains two pieces of information: the direction of the displacement and the length of the displacement.

[0091] S303, such as Figure 3 As shown in Figure (b), the time interval between two specified tactile encrypted epidermal image frames is calculated. T, and based on step S302, calculate the difference in the position cell matrix of the specified encrypted epidermal particles in the specified two frames. P, through the difference of the position cell matrices P divided by the time interval T, thus obtaining the velocity S of the encrypted epidermal particles under tactile action, such as S 1to2 = P 1to2 / T represents the velocity of the specified encrypted epidermal particles in the first and second frames of the image; the two encrypted epidermal images can be specified multiple times to obtain the velocities of different encrypted epidermal particles in multiple stages of the dynamic tactile process, which together form the velocity tensor S. all In a preferred embodiment, the time interval between two frames is specified. T is 0.1 seconds;

[0092] S304, such as Figure 3As shown in Figure (c), the ambient light is adjusted by changing the position, type, or intensity of the light source. Images of different surface morphologies reflected by the tactile feedback layer of the tactile-sensitive epidermis under different ambient light conditions are captured by photographing the subcutaneous tissue of the tactile-sensitive epidermis. The depth matrix H of the tactile-sensitive epidermal particles in each frame is then obtained using a photometric stereo algorithm. All depth matrices together form the depth tensor H. all .

[0093] In a preferred embodiment, due to the time interval for acquiring images Since t is 0.1 seconds, the light source needs to be switched and 4 images need to be taken within 0.1 seconds. It should be noted that the first three images taken every 0.1 seconds in this step are not used to extract the position and velocity of the encrypted epidermal particles in order to save computation.

[0094] In a preferred embodiment of the present invention, S400 is implemented as follows:

[0095] Based on the position cell matrix P obtained in step S302, the velocity matrix S obtained in step S303, and the depth matrix H obtained in step S304, two modalities are selected for coupling to obtain the dual-modal dynamic tactile features T of the tactile encrypted epidermal image. DBL :T DBL =f(P,S) or T DBL =f(P,H) or T DBL =f(S,H); Alternatively, the three modalities of "force-velocity-depth" can be fully coupled to obtain the multimodal dynamic tactile feature T. TRI :T TRI =f(P,S,H);

[0096] The encryption source of the multimodal dynamic tactile encryption method is multimodal. Multimodal means that it refers to the coupling result of at least two biotactile physical quantities in the mechanical changes (including the magnitude and direction of force of normal force, shear force and torsional force) during the biotactile generation process, the velocity change per unit time during the biotactile application process, and the depth change of the encrypted epidermal elastic layer and the encrypted epidermal granular layer caused by biotactile sensation. Therefore, the function f in step S400 can be, but is not limited to, a linear function or a nonlinear function such as an exponential function or a power function.

[0097] In a preferred embodiment, in the first frame of the tactile encrypted epidermal image, a power function is selected as the coupling function of the bimodal tactile features, with the position matrix as the base of the power function and the velocity matrix as the power. The corresponding bimodal tactile features can then be expressed as: T DBL =P S A combination of linear and power functions is chosen as the coupling function for multimodal tactile features, expressed as: T TRI =(P+a×S)H , where P is the position cell matrix of the encrypted epidermal particles in a certain frame, S is the velocity matrix of the encrypted epidermal particles in two adjacent frames, H is the depth matrix of the encrypted epidermal particles in a certain frame, and a is a user-defined coefficient matrix.

[0098] Similarly, the haptic encryption skin images of other frames can be coupled with different numbers of modalities.

[0099] In a preferred embodiment of the present invention, S500 is implemented, specifically including the following process:

[0100] S501 specifies a standard encryption method. In this embodiment, DES (Data Encryption Standard) encryption is selected. This encryption method has significant advantages such as fast processing speed and better suitability for hardware execution. Other encryption methods that can be selected include, but are not limited to, 3DES, IDEA, Blowfish, Skipjack, and AES.

[0101] S502, In this embodiment, based on the tactile features obtained from multiple tactile encrypted epidermal images, the above features are preprocessed into the data format required for DES encryption.

[0102] S503, In this embodiment, for the DES encryption method, the user can customize a 64-bit initial key Key 1. For example, if the letter "m" is selected, the ASCII code value of "m" is 01001101 (8 bits, recorded as the first byte). Then, the first byte is subjected to seven user-defined operations: AND operation with itself, OR operation with itself, two's complement, left shift by 4 bits, right shift by 3 bits, left shift by 2 bits and then invert, and right shift by 5 bits and then find the two's complement, respectively, to obtain the second to eighth bytes. After concatenating the above eight bytes, the user-defined 64-bit initial key Key 1 is obtained.

[0103] The initial key can also be letters, numbers, or sound fragments. The above initial keys are preprocessed into the data format required by the specified standard encryption method.

[0104] S504, the preprocessed initial key Key 1 is DES encrypted together with the preprocessed bimodal or multimodal tactile feature T1 of the first frame image to obtain ciphertext 1; ciphertext 1 is then used as a new key and DES encrypted together with the preprocessed bimodal or multimodal tactile feature T2 of the second frame image to obtain the next level key, and so on, until the nth level ciphertext n is generated. The ciphertext n is the final encryption result of the entire dynamic multimodal tactile process.

[0105] Based on the same inventive concept, such as Figure 4As shown in Figure (a), the present invention provides a tactile encrypted skin for implementing the above-mentioned multimodal dynamic tactile encryption method, comprising a tactile encrypted epidermis, tactile encrypted subcutaneous tissue, and a tactile encrypted skeleton. The tactile encrypted epidermis is located at the top and undergoes morphological changes under external tactile stimulation; the tactile encrypted subcutaneous tissue is located below the tactile encrypted skin and records the morphological changes of the tactile encrypted epidermis; the tactile encrypted skeleton provides fixed support for the tactile encrypted epidermis and the tactile encrypted subcutaneous tissue.

[0106] like Figure 4 As shown in Figure (b), in a preferred embodiment of the present invention, the tactile encrypted skin includes, from bottom to top, an encrypted skin elastic layer 101, an encrypted skin particle layer 102, an encrypted skin reflection layer 103, and an encrypted skin wear-resistant layer 104.

[0107] The densified outer elastic layer 101 can be prepared using polydimethylsiloxane (PDMS) or transparent hydrogel. The high transparency of the material ensures that light from the light source can pass through the material smoothly, illuminating the internal densified outer granular layer and the densified outer reflector layer. PDMS can be mixed with a matrix and curing agent in a 30:1 ratio, then molded in a uniform 3D printed mold, and cured in an oven at 40°C for 10 hours to obtain a transparent elastomer with a low Young's modulus. This is beneficial for producing greater deformation under external tactile stimulation, thus improving sensitivity.

[0108] The encrypted epidermal granular layer is embedded in the upper surface of the encrypted epidermal elastic layer (e.g. Figure 4 (as shown in Figure (b)). The encrypted skin particle layer can be generated by doping with microparticles or printing markers. If fluorescent microparticles are selected as the encrypted skin particles, they will only emit light under illumination of a light source of a specified wavelength, achieving a tracing effect. When there is no light source of a specified wavelength, the encrypted skin particle layer can achieve cloaking, thereby controlling dynamic tactile encryption to only be performed under specified ambient light conditions.

[0109] The doped microparticles can be first laid into a single layer using the water film method, and then transferred onto the prepared densified elastic skin layer using the transfer method. By repeating the transfer process on this basis, a thin layer of transparent elastomer can be prepared, thus creating multi-layered densified skin particles. The multi-layered densified skin particles are arranged longitudinally in a staggered manner, ensuring that the densified skin particles in different layers do not obstruct each other.

[0110] If printed markers are used as the densified skin particles, the method is similar to the above-mentioned microparticle preparation technology. The only difference is that the preparation of single-layer microparticles is replaced by the printing process of markers, such as screen printing or hard mask printing.

[0111] Encrypted skin particles can also be prepared by dispensing and printing.

[0112] The markers can be made of pigments, paints, etc., and their colors need to have strong contrast with the encrypted skin mapping layer material to facilitate image observation. The encrypted skin mapping layer is prepared on the encrypted skin elastic layer through processes such as spraying, printing, sputtering, or evaporation, forming a uniform film with a thickness not exceeding 1 mm, used to map and provide feedback on the surface morphology features of the tactile contact surface. In a preferred embodiment, silver powder and PDMS matrix are used as the doped material of the encrypted skin mapping layer, and the dispersant can be an organic solvent such as toluene. Here, the contact surface refers to the surface of the encrypted skin that contacts the object applying dynamic tactile sensation; for example, when applying dynamic tactile sensation with a finger, the contact surface is the fingertip.

[0113] The tactile surface wear-resistant layer is prepared by spin coating onto the tactile surface mapping layer to reduce wear on the tactile surface mapping layer during contact. In a preferred embodiment, a material prepared by using a PDMS matrix and a curing agent in a 10:1 ratio is used as the tactile surface wear-resistant layer. It is spin-coated onto the tactile surface mapping layer at a speed of 600 rpm, and the entire tactile surface is placed in an oven and cured at 60°C for 1 hour.

[0114] The tactile encrypted skin in the above embodiments provides users with a way to acquire and collect bio-tactile signals. The bio-tactile signals include the surface morphology changes and three-dimensional displacement field changes of the encrypted epidermal mapping layer and the encrypted epidermal granular layer after being subjected to bio-tactile action. It fully considers the individual differences in bio-tactile sensation and the differences between different tactile processes, and can overcome the shortcomings of biometric encryption technology. It creates a more secure, reliable and easy-to-use encryption technology in the Internet of Things and body area networks, and better protects users' information and property security.

[0115] In a preferred embodiment of the present invention, the tactile encryption skeleton can be designed as other geometric structures such as cuboids, cubes and hemispheres according to application requirements, for fixing the tactile encryption epidermis and tactile encryption subcutaneous tissue;

[0116] The medium in the tactile encryption skeleton can be air or other transparent materials with different refractive indices.

[0117] In a preferred embodiment of the present invention, the tactile encryption subcutaneous tissue is located below the tactile encryption epidermis and is used to capture the surface morphology and three-dimensional displacement field changes generated by the tactile encryption epidermis, and then transmit the continuous image frames to the host computer.

[0118] The tactile encryption subcutaneous tissue includes an image sensor, a digital signal processing chip (DSP), a metasurface lens, and a light source;

[0119] The metasurface lens is a two-dimensional planar thin layer that can achieve converging imaging, replacing the traditional lens group, thereby significantly reducing the overall thickness of the tactile encrypted skin; this design replaces the traditional lens group, enabling a compact design of the tactile encrypted skin, which is beneficial for its integration into the fingertips of robotic dexterity hands or wearable devices;

[0120] The light source is an LED or LD light source, fixed on the inner wall of the tactile encryption skeleton, and used in conjunction with a light guide plate to provide a uniform surface light source.

[0121] In a preferred embodiment, to facilitate the implementation of tactile electronic signatures, the tactile encryption skeleton is designed as follows: Figure 4 The slope shown in Figure (a) is designed to match writing habits. The light source uses an array of LED beads and a light guide plate, which is a uniform surface light source radiating from within the tactile encryption skeleton towards the tactile encryption surface to illuminate the entire bottom of the tactile encryption surface; the color of the LED beads is not limited, and the same light source (such as white light) or a combination of different colored light sources can be used; the light intensity of the LED beads is adjustable. Furthermore, the light source uses 12 white LED beads and a light guide plate, evenly arranged in the four corners of the tactile encryption skeleton, with 3 white LED beads in each corner. By controlling the light sources in the four corners to be lit individually and sequentially, images of the tactile encryption surface under different illumination angles can be obtained.

[0122] Based on the same inventive concept, other embodiments of the present invention provide a tactile encryption system, such as... Figure 5 As shown, this is achieved based on the aforementioned tactile encrypted skin and multimodal dynamic tactile encryption method;

[0123] By sliding a finger across the haptic encrypted skin to write a signature, the haptic encrypted skin will encrypt the displacement, velocity, and depth of the encrypted skin particles throughout the entire dynamic process. Finally, the host computer screen will display a QR code corresponding to the haptic encryption result. By scanning the QR code and entering the initial key specified by the user, the entire encryption process of the encrypted object can be obtained.

[0124] like Figure 6 As shown, the vector displacement and normal force relationship of the densified epidermal particles in the elastic layer can be extracted using standard mechanical calibration equipment;

[0125] In this embodiment, when a user uses the tactile encrypted skin as a substrate for creations such as handwritten signatures and electronic paintings, the multimodal dynamic tactile encryption method can convert the dynamic tactile changes throughout the process into coupled information corresponding to at least two of force, speed, and depth, and encrypt it. Therefore, it can be used as an encryption means for creations such as handwritten signatures and electronic paintings, encrypting the tactile signal process generated by the creator's handwriting, thereby achieving highly secure bio-encryption that cannot be cloned.

[0126] Figure 7 Figure (a) shows the dynamic process of a user writing the electronic signature "mems" on a tactile encrypted skin in 2.8 seconds using a pen with a rubber tip. The figure not only captures the tactile trajectory in real time, but also displays the displacement magnitude and direction of the encrypted skin particles at the pen tip for the user to observe. This application is expected to be promoted in places with high density of personal biometrics and identity verification, such as banks and exchanges, to replace traditional electronic signatures or handwritten signatures and provide users with a unique and unclonable tactile signature application solution.

[0127] Figure 7 Figure (b) shows the brush marks left in real time when a user uses haptic-encrypted skin as a substrate under drawing paper or a digital drawing tablet. The haptic changes throughout the drawing process are recorded and encrypted in real time, ultimately forming... Figure 7 Figure (b) shows the ciphertext. This ciphertext can be considered a unique identifier for the artwork. Only users who possess the original key and the specific content of the custom function in the tactile encryption algorithm can reconstruct the entire creation process of the artwork. In the future, this tactile identifier will be beneficial for the authentication of artworks.

[0128] Other embodiments of the present invention also propose an IoT command encryption method based on the aforementioned multimodal dynamic tactile encryption method, such as... Figure 8 As shown, users can customize a tactile action. The corresponding multimodal tactile features of this action are then encrypted multiple times with an unencrypted IoT command, ultimately forming a completely new command that can remotely control IoT terminal devices via the cloud. Since users' bio-tactile senses exhibit individual differences and variations between different tactile processes, this multimodal dynamic tactile encryption method offers the advantage of being unclonable, making it more secure and reliable than traditional bio-encryption methods, thus possessing strong resistance to hacking. Furthermore, because touch is not an explicit feature like voice or gestures, tactile encryption can be performed in crowded public places without concerns about third-party eavesdropping and data leakage.

[0129] Figure 9 This invention showcases smart clothing with tactile encryption functionality, implemented using the IoT command encryption method described above. By embedding tactile encryption skin into the clothing, and by handwriting a pre-recorded dynamic tactile signature on the garment, the safe can be remotely and wirelessly opened after data verification. Compared to traditional digital passwords and fingerprint passwords, this encryption command offers a higher level of security and is expected to be widely adopted and applied in the Internet of Things (IoT).

[0130] The above are some preferred embodiments of the present invention illustrated in conjunction with the accompanying drawings, for a more detailed understanding of the technical solutions of the present invention. It will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions resulting from these changes or substitutions will all fall within the scope of protection of the present invention.

[0131] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention. The above preferred features can be used in any combination without conflict.

Claims

1. A multimodal dynamic tactile encryption method, characterized in that, include: Applied to haptic encrypted skin, the haptic encrypted skin includes: A tactile encrypted skin, located on top, undergoes morphological changes under the influence of external dynamic tactile stimulation; Tactile encryption subcutaneous tissue, located beneath the tactile encryption epidermis, is used to capture images of morphological changes in the tactile encryption epidermis; The tactile encryption skin includes: An encrypted elastic skin layer, wherein the encrypted elastic skin layer is a transparent layer and is located at the bottom layer; An encrypted outer skin particle layer is embedded within the encrypted outer skin elastic layer. The particle layer contains a number of particles, which are obtained by doping microparticles or printing markers. The encrypted outer skin particle layer can be configured as a single layer or multiple layers, wherein the particles in different layers are staggered and do not obstruct each other. An encrypted epidermal reflection layer is located above the encrypted epidermal granule layer and has a reflective function; An encrypted skin wear-resistant layer is disposed above the encrypted skin reflection layer to reduce wear on the encrypted skin reflection layer during contact use; When dynamic tactile sensation is applied to the tactile encrypted skin, the encrypted skin reflection layer retains the surface morphology of the contact surface without damage due to the reflection effect. The particles in the encrypted skin particle layer will generate corresponding displacement with the external force. The encrypted skin elastic layer allows the particles in the encrypted skin particle layer to undergo depth changes. The tactilely encrypted subcutaneous tissue includes: An image sensor that collects light rays converged by a metasurface lens and converts the optical signal into an electrical signal; A metasurface lens is used to capture images of the tactile encrypted skin in a planar form. The images of surface morphology changes and three-dimensional displacement field changes generated by the image layer and the particle layer of the encrypted skin after being subjected to dynamic tactile action are converged onto the image sensor. The planar metasurface lens is used to reduce the overall thickness of the tactile encrypted skin. A digital signal processing chip, which processes and transmits the electrical signals of the image sensor; A light source, used to illuminate the tactilely encrypted skin; The encryption method includes the following steps: S1, Dynamic tactile sensation is applied to the tactile encrypted skin; S2, through the tactile encrypted subcutaneous tissue, image data generated by the tactile encrypted epidermis in the initial state and during dynamic tactile action is collected; S3, Based on the image data, obtain the position cell tensor, velocity tensor, and depth tensor of the encrypted epidermal granular layer before and after being stimulated by touch; The process of acquiring the image data includes: The image sensor in the tactile encryption subcutaneous tissue is used to acquire tactile encryption epidermal images of each frame throughout the entire process of dynamic tactile action from the initial state to the final state. By pre-specifying the time interval for image acquisition t, acquire tactile encrypted epidermal images at multiple time points, with a total number of tactile encrypted epidermal images of n; The process of obtaining the location cell tensor is as follows: The acquired tactile encrypted epidermal images were preprocessed, and the position cell matrix of the encrypted epidermal granular layer in the tactile encrypted epidermal epidermis under the initial no tactile action was marked as P1; After a tactile sensation is applied, the displacement change of each encrypted epidermal particle is tracked, including the direction and length of the displacement. The position cell matrix of that encrypted epidermal particle layer is updated in each frame until the final state of the tactile sensation is reached, resulting in the position cell matrix P of the last encrypted epidermal particle layer. n ; Based on the changes in the positional cell matrix of the encrypted epidermal particles between adjacent image frames, the type, direction, and magnitude of the tactile force applied can be deduced. All the position cell matrices together form the position cell tensor P. all ; The process of obtaining the velocity tensor is as follows: The time interval between two specified tactile encrypted skin image frames is calculated. T, calculate the difference in the position cell matrix of a specified encrypted epidermal particle in two frames. P; Through the difference of the location cell matrix P divided by the time interval T, the velocity S of the specified encrypted skin particles during the tactile action in these two frames is obtained; By specifying two frames of tactile encrypted epidermal images multiple times, the velocity matrix of different encrypted epidermal particles in multiple stages of dynamic tactile process is obtained. All velocity matrices together form the velocity tensor S. all ; The process of obtaining the depth tensor is as follows: Ambient light can be adjusted by changing the position, type, or intensity of the light source. The image sensor in the tactile encryption subcutaneous tissue captures images of different surface morphologies reflected by the encryption epidermal reflection layer in the tactile encryption epidermis under different ambient light conditions, when subjected to tactile action. The depth matrix H of the encrypted epidermal granular layer in each frame is obtained using a photometric stereo algorithm. All the depth matrices together form the depth tensor H. all ; S4. Based on the position cell tensor, velocity tensor, and depth tensor, construct a bimodal dynamic tactile feature or a multimodal dynamic tactile feature based on dynamic force-velocity-depth coupling. The process of acquiring the dual-modal dynamic tactile features is as follows: Based on the position cell matrix P, velocity matrix S, and depth matrix H, two modalities are selected for coupling to obtain the dual-modal dynamic tactile features T of the tactile encrypted epidermal image. DBL :T DBL =f(P,S) or T DBL =f(P,H) or T DBL =f(S,H); The process of acquiring the multimodal dynamic tactile features is as follows: By fully coupling the three modalities of "force-velocity-depth", we obtain the multimodal dynamic tactile feature T. TRI :T TRI =f(P,S,H); S5, perform multi-level standard encryption based on a custom initial key on the bimodal dynamic tactile feature or multimodal dynamic tactile feature to obtain the final dynamic multimodal tactile process encryption result.

2. The multimodal dynamic tactile encryption method according to claim 1, characterized in that, f is a linear function or a nonlinear function, wherein the nonlinear function is an exponential function or a power function.

3. The multimodal dynamic tactile encryption method according to claim 1, characterized in that, The dual-modal dynamic haptic features or multi-modal dynamic haptic features are subjected to multi-level standard encryption based on a custom initial key to obtain the final dynamic multi-modal haptic process encryption result, including: Specify a standard encryption method; The bimodal or multimodal dynamic tactile features are preprocessed into the data format required by the standard encryption method. Customize the initial key and preprocess it into the data format required by the specified standard encryption method; The preprocessed custom initial key and the preprocessed bimodal or multimodal dynamic haptic feature T1 of the first frame image are encrypted according to the standard encryption method to obtain the first level ciphertext; The first-level ciphertext is used as a new key and encrypted with the bimodal or multimodal dynamic tactile feature T2 of the preprocessed second frame image according to the standard encryption method to obtain the key for the next level, and so on, until the nth level ciphertext is generated. The nth level ciphertext is the final encrypted result of the entire dynamic multimodal haptic process.

4. The multimodal dynamic tactile encryption method according to claim 1, characterized in that, The tactile encrypted skin also includes: A tactile encryption framework that provides fixed support for the tactile encryption epidermis and tactile encryption subcutaneous tissue.

5. The multimodal dynamic tactile encryption method according to claim 4, characterized in that, The medium of the tactile encryption skeleton is air or a transparent material with a specified refractive index.

6. A tactile encryption system, characterized in that, The multimodal dynamic tactile encryption method according to any one of claims 1-5 is used to encrypt the tactile signal process generated by handwriting on a substrate of tactile encrypted skin as a handwritten signature or electronic drawing.

7. A method for encrypting Internet of Things (IoT) commands, characterized in that, include: Define a custom tactile motion; Based on the tactile action, the corresponding multimodal dynamic tactile features are obtained using the multimodal dynamic tactile encryption method described in any one of claims 1-5. After multiple rounds of encryption with the unencrypted IoT command, a completely new command is finally formed. The new commands allow for remote control of IoT terminal devices via the cloud.

Images