CN108139856B

CN108139856B - Signature authentication method, terminal, handwriting pen and system

Info

Publication number: CN108139856B
Application number: CN201680028530.4A
Authority: CN
Inventors: 李茹; 吴黄伟
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-08-31
Filing date: 2016-08-31
Publication date: 2020-07-07
Anticipated expiration: 2036-08-31
Also published as: WO2018040009A1; CN108139856A

Abstract

The embodiment of the invention relates to a signature authentication method, a terminal, a handwriting pen and a system. The method comprises the steps that when a user signs on a touch panel of the terminal through a handwriting pen, the terminal detects first signature data, wherein the first signature data comprise coordinate information of a contact point of the handwriting pen and the touch panel and pressure information of the handwriting pen on the touch panel at the contact point; and the terminal receives second signature data sent by the handwriting pen, wherein the second signature data comprises the motion track information of the handwriting pen and the pressure information of the user on the handwriting pen, which are detected by the handwriting pen when the user signs on the touch panel through the handwriting pen. And matching and comparing the first signature data and the second signature data with pre-stored signature template data to obtain a matching rate. And when the matching rate is not lower than a preset matching rate threshold value, the signature passes the authentication. According to the embodiment of the invention, more user signature characteristic data are extracted through the stylus pen, the difficulty of an attacker simulating user signature information is increased, and the safety of the signature authentication system is improved.

Description

Signature authentication method, terminal, handwriting pen and system

Technical Field

The invention relates to the technical field of signature authentication of a stylus pen, in particular to a signature authentication method, a terminal, a stylus pen and a system.

Background

The handwriting pen signature technology has become an important technology for confirming the identity of a user in a virtual environment of a network system. A user inputs a handwritten signature on a touch panel of the terminal by using a stylus pen for authentication, and the terminal detects relevant data of the handwritten signature through the touch panel and a sensor. The terminal compares and matches the detected signature related data with the pre-stored signature template data to identify the authenticity of the signature and judge whether the user input handwritten signature passes the authentication. The data related to the signature detected by the terminal comprises signature image information, pressure information of the stylus pen on the touch panel and other information

In the prior art, after an attacker trying to imitate a handwritten signature of a user obtains signature template data of the user, the signature template data is sequentially presented to a terminal authentication system, the handwritten signature of the user is forged, and signature authentication is passed. After the authentication of the forged user handwritten signature passes, an attacker can illegally obtain the related authority of the user, and further threatens the personal or property safety of the user.

In the prior art, only the terminal detects the relevant data of the handwritten signature as a signature template, so that the moldability is high, and the safety of the conventional handwritten signature authentication system is poor.

Disclosure of Invention

The embodiment of the invention relates to a signature authentication method, a terminal, a handwriting pen and a system, which improve the safety of a handwriting signature authentication system.

In a first aspect, an embodiment of the present invention provides a signature authentication method, where the method includes: when a user signs on a touch panel of the terminal through a handwriting pen, the terminal detects first signature data, wherein the first signature data comprises coordinate information of a contact point of the handwriting pen and the touch panel and pressure information of the handwriting pen on the touch panel at the contact point; and the terminal receives second signature data sent by the handwriting pen, wherein the second signature data comprises the motion track information of the handwriting pen and the pressure information of the user on the handwriting pen, which are detected by the handwriting pen when the user signs on the touch panel through the handwriting pen. And matching and comparing the first signature data and the second signature data with pre-stored signature template data to obtain a matching rate. And when the matching rate is not lower than a preset matching rate threshold value, the signature passes the authentication.

In the embodiment of the invention, in the process that the user inputs the handwritten signature on the touch panel of the terminal by using the stylus pen, more user signature characteristic data are extracted by the stylus pen, and compared and matched, so that the difficulty of an attacker imitating user signature information is increased, and the safety of a signature authentication system is improved.

In one possible embodiment, the sampling time and sampling frequency of the first signature data and the second signature data are kept synchronized.

The signature authentication system provided by the embodiment of the invention enables an attacker to simulate the handwriting of the user and also simulate the hand action of the user, thereby greatly improving the safety of the signature authentication system.

In one possible implementation mode, the signature corresponds to a first signature characteristic point and a second signature characteristic point, the first signature characteristic point comprises at least one point in a set formed by contact points, and the second signature characteristic point comprises at least one point in a set of points in a motion track of an area outside the touch panel of the stylus pen; extracting data corresponding to the first signature characteristic point and the second signature characteristic point from the first signature data and the second signature data; and matching and comparing the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to obtain the matching rate.

In one possible embodiment, the data corresponding to the first signature feature point includes: coordinate information of a contact point corresponding to the first signature characteristic point, pressure information of the stylus pen on the touch panel at the contact point corresponding to the first signature characteristic point, position information of the stylus pen when the sampling time of the position information of the stylus pen is the same as that of the first signature characteristic point, and pressure information of a user on the stylus pen; the position information of the handwriting pen is obtained through the motion track information of the handwriting pen.

After the coordinate system for detecting the motion track of the stylus pen and the coordinate system for detecting the coordinate of the contact point are transformed and unified, the position coordinate of the pen end of the stylus pen in the area of the touch panel is superposed with the position coordinate of the contact point.

In one possible embodiment, the data corresponding to the second signature feature point includes: and the position information of the handwriting pen corresponding to the second signature characteristic point and the pressure information of the user on the handwriting pen.

In one possible embodiment, the second signature data further includes: the handwriting pen detects the acceleration of the handwriting pen when a user signs a signature on the touch panel through the handwriting pen, information of the pressed area and the shape of the pressed area of the handwriting pen under the pressure of the user, and information of the distance between the pressed area of the handwriting pen and the pen end of the handwriting pen.

In one possible embodiment, the first signature feature point specifically includes one or more of a first contact point, a last contact point, a discontinuous contact point, or a contact point with a large change in curvature.

Specifically, the discrete contact points correspond to the starting points of different strokes in the signature. The point with large curvature change corresponds to the bending point in the stroke.

In a possible implementation, the second signature feature point specifically includes one or more of the following points: the point with the largest curvature in the curve corresponding to the motion trail of each discontinuous stylus pen in the area above the touch panel or the point with the farthest distance from the touch panel in the curve corresponding to the motion trail of each discontinuous stylus pen in the area above the touch panel.

And the point with the largest curvature in the curve corresponding to the motion trail of each discontinuous handwriting pen or the point which is farthest away from the touch panel in the curve corresponding to the motion trail of each discontinuous handwriting pen corresponds to the highest point of the pen lifted by the handwriting pen between the two strokes.

In one possible implementation, a first signature feature point is extracted from the contact points; projecting the motion track of the pen end of the stylus pen on a first plane where the touch panel is located to obtain a first motion track of the pen end of the stylus pen; projecting the motion trail of the pen end of the stylus pen on a second plane and a third plane which are perpendicular to the first plane to obtain a second motion trail and a third motion trail of the pen end of the stylus pen, wherein the second plane is perpendicular to the third plane; extracting a second signature characteristic point from at least one of the first motion track, the second motion track and the third motion track; extracting data corresponding to the first signature characteristic point and the second signature characteristic point from the first signature data and the second signature data; and matching and comparing the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to obtain the matching rate.

In one possible implementation, the matching rate threshold is preset according to the environment in which the terminal is located.

The embodiment of the invention can also set different matching rate thresholds according to the environment of the terminal, can adapt to the actual requirements of users and has good application prospect.

In a second aspect, an embodiment of the present invention provides a signature authentication method, where the method includes: when a user signs on a touch panel of the terminal through a handwriting pen, the handwriting pen detects second signature data, and the second signature data comprises motion track information of the handwriting pen and pressure information of the user on the handwriting pen; and the handwriting pen sends the second signature data to the terminal so that the terminal determines whether the signature authentication passes according to the second signature data and first signature data detected by the terminal, wherein the first signature data comprises coordinate information of a contact point of the handwriting pen and the touch panel and pressure information of the handwriting pen on the touch panel at the contact point.

In particular, the second signature characteristic data reflects hand motion characteristics of the user. When different users input handwritten signatures, the force, shape and distance of the pen holding area from the pen end may be different.

In a third aspect, an embodiment of the present invention provides a terminal, where the terminal includes: touch panel, display panel, sensor, treater, memory, communication unit.

And the touch panel is used for receiving the signature input by the user through the handwriting pen. And the display panel is used for displaying the image of the signature. And the touch panel is also used for detecting the coordinate information of the contact point of the stylus pen and the touch panel. The sensor is used for detecting the pressure information of the stylus pen on the touch panel at the contact point; the coordinate information of the contact point and the pressure information of the stylus pen on the touch panel at the contact point constitute first signature data. And the communication unit is used for establishing communication connection with the stylus pen and receiving second signature data sent by the stylus pen, wherein the second signature data comprise motion track information of the stylus pen and pressure information of the user on the stylus pen, which are detected by the stylus pen when the user signs on the touch panel through the stylus pen. And the memory is used for storing a preset matching rate threshold value. The processor is used for matching and comparing the first signature data and the second signature data with pre-stored signature template data to obtain a matching rate; and when the matching rate is not lower than the preset matching rate threshold, indicating the display panel to display prompt information that the signature authentication passes. And the display panel is also used for displaying prompt information that the signature passes the authentication.

In a possible implementation, the processor is further configured to send control information of a sampling time and a sampling frequency of the stylus to control the sampling time and the sampling frequency of the first signature data and the second signature data to be kept synchronized.

In one possible implementation mode, the signature corresponds to a first signature characteristic point and a second signature characteristic point, the first signature characteristic point comprises at least one point in a set formed by contact points, and the second signature characteristic point comprises at least one point in a set of points in a motion track of an area outside the touch panel of the stylus pen; the processor is specifically used for extracting data corresponding to the first signature characteristic point and the second signature characteristic point from the first signature data and the second signature data; and matching and comparing the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to obtain the matching rate.

In a possible embodiment, the processor is specifically configured to extract a first signature feature point from the contact points; projecting the motion track of the pen end of the stylus pen on a first plane where the touch panel is located to obtain a first motion track of the pen end of the stylus pen; projecting the motion trail of the pen end of the stylus pen on a second plane and a third plane which are perpendicular to the first plane to obtain a second motion trail and a third motion trail of the pen end of the stylus pen, wherein the second plane is perpendicular to the third plane; extracting a second signature characteristic point from at least one of the first motion track, the second motion track and the third motion track; extracting data corresponding to the first signature characteristic point and the second signature characteristic point from the first signature data and the second signature data; and matching and comparing the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to obtain the matching rate.

In a possible implementation manner, the processor is further configured to determine an environment where the terminal is located according to a network to which the communication unit is connected, and preset a matching rate threshold according to the environment where the terminal is located.

In a fourth aspect, an embodiment of the present invention provides a stylus pen, including: sensor unit, treater, communication unit.

And the sensor unit is used for detecting the motion trail information of the handwriting pen and the pressure information of the user on the handwriting pen when the user signs a signature on the touch panel of the terminal through the handwriting pen.

And the processor is used for converting the motion trail information of the handwriting pen and the pressure information of the user on the handwriting pen into second signature data which can be processed by the terminal and indicating the communication unit to send the second signature data to the terminal.

And the communication unit is used for establishing communication connection with the terminal and sending the second signature data to the terminal.

In a possible implementation, the sensor unit is further configured to detect acceleration of the stylus pen, information of a pressed area and shape of the pressed area of the stylus pen under pressure of the user, and information of a distance of the pressed area of the stylus pen from a pen tip of the stylus pen, when the user signs a signature on the touch panel of the terminal through the stylus pen.

In a possible implementation, the communication unit is further configured to receive control information sent by the terminal for the sampling time and the sampling frequency of the sensor unit, so as to control the sampling time and the sampling frequency of the first signature data and the second signature data to be kept synchronous.

In a fifth aspect, an embodiment of the present invention provides a signature authentication system, which includes the terminal provided in the third aspect and the stylus pen provided in the fourth aspect.

According to the signature authentication method, the terminal, the handwriting pen and the system provided by the embodiment of the invention, the terminal and the handwriting pen simultaneously detect the related data of the signature, the related data of the signature is compared and matched with the pre-stored signature template data, and whether the signature authentication passes or not is determined according to the matching rate. In the embodiment of the invention, in the process that the user inputs the handwritten signature on the touch panel of the terminal by using the stylus pen, more user signature characteristic data are extracted by the stylus pen, and compared and matched, so that an attacker still needs to simulate the hand action of the user while simulating the handwriting of the user, the difficulty of simulating the signature information of the user by the attacker is increased, and the safety of the signature authentication system is greatly improved.

Drawings

Fig. 1 is a schematic diagram of a signature authentication system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a terminal architecture provided in the present invention;

FIG. 3 is a schematic diagram of a structure of a stylus according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a coordinate system and a signature of a signature authentication system according to an embodiment of the present invention;

fig. 5 is a signaling interaction diagram of a signature authentication system method according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments, but not all embodiments, of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The attacker refers to other users who try to imitate the characteristics of the handwritten signature input by the user and imitate the relevant characteristics of the hand motion and the like of the user in the process of inputting the handwritten signature by the user so as to pass the authentication of the terminal. The "other user" mentioned in the embodiment of the present invention refers to a user a who inputs the handwritten signature a, and the "other user" is different from the user a who inputs the handwritten signature a. And each user corresponds to the relevant data of the handwritten signature of the user one by one. A refers to an arbitrary user.

The "contact point" mentioned in the embodiments of the present invention refers to a contact point of the stylus pen with the touch panel. It will be appreciated that the point of contact of the stylus with the touch panel constitutes a handwritten signature image.

The motion trail of the stylus pen mentioned in the embodiment of the invention refers to a curve formed by corresponding points of a certain point on the stylus pen at different spatial positions. For example, the curve formed by different points crossed by the pen end in space is the motion track of the pen end.

The "pen holding posture" of the user mentioned in the embodiment of the present invention refers to a pressed area and/or pressed shape of the stylus pen when the user holds the pen. The 'pen holding strength' of the user mentioned in the embodiment of the invention refers to the pressure information of the handwriting pen when the user holds the pen. It should be noted that different users may correspond to different pen-holding postures, pen-holding forces, and other characteristic information.

Reference to "curvature" in reference to embodiments of the present invention refers to the amount of curvature of a curve at a point. The larger the curvature, the more curved the curve is. "points of greater change in curvature" refer to points where the curvature-bending transformation is more pronounced. For example, for a particular word in a signature, the stroke "carabiner ()" has two points of greater curvature change. The stroke "horizontal line-" has no point with large curvature change.

The "matching rate" mentioned in the embodiment of the present invention refers to the matching degree of the data after the data is compared with the data.

The matching rate threshold mentioned in the embodiment of the present invention refers to a matching rate threshold (matching rate threshold) that can be preset by the terminal when the user inputs a handwritten signature for authentication. When a user inputs a handwritten signature for authentication, when the matching rate of the relevant data of the handwritten signature and the signature template data is not lower than the threshold value of the matching rate, the terminal can determine that the handwritten signature of the user passes the authentication. For example, when the matching rate threshold is 70%, and the matching rate of the data related to the handwritten signature of the user calculated by the terminal and the signature template data is 75%, the terminal determines that the handwritten signature of the user passes authentication because 75% > 70%.

The "preset" mentioned in the embodiment of the present invention refers to the preset. The "preset matching rate threshold" means that a matching rate threshold is preset before a user inputs a handwritten signature for authentication, so as to determine whether the authentication is passed or not.

The "first signature data" mentioned in the embodiment of the present invention refers to data related to a signature detected by the terminal, such as image information of the signature, pressure information of a stylus pen on a touch panel of the terminal, and the like.

The "second signature data" mentioned in the embodiment of the present invention refers to data related to a signature detected by a stylus pen, for example, pressure information of a user on the stylus pen and motion trajectory information of the stylus pen during a process of inputting a handwritten signature by the user through the stylus pen.

The "temporal relationship" mentioned in the embodiment of the present invention refers to a detection temporal relationship of "first signature data" and "second signature data". For example, when the sampling time and the sampling frequency of the touch panel and the stylus pen are kept synchronized, the first signature data and the second signature data corresponding to the same sampling time are corresponding.

The "spatial relationship" mentioned in the embodiment of the present invention refers to a spatial positional relationship of points corresponding to the "first signature data" and the "second signature data". It can be understood that, when the pen tip of the stylus pen is in contact with the touch panel, the pen tip of the stylus pen is located at the same position as the contact point in the same coordinate system.

The "feature points" mentioned in the embodiments of the present invention refer to representative points in the handwritten signature image of the user. Taking the handwritten signature of the user as the name of the Chinese character as an example, the name and the name of the user are both composed of strokes. The different strokes may not be consecutive. The writing habit and writing size of each user are different. But the strokes of each word in the signature are fixed. Therefore, the starting point of each stroke of the user handwritten signature can be selected as the characteristic point of the user handwritten signature. Wherein the starting point of each stroke is embodied as a discontinuous contact point detected by the touch panel.

Further, the "signature feature point" mentioned in the embodiment of the present invention refers to a representative feature point extracted from a feature point corresponding to the first signature data and a feature point corresponding to the second signature data. The touch panel is provided with a touch screen, a handwriting pen and a touch panel, wherein a point of the handwriting pen contacting with the touch panel is a first characteristic point, and a point of the handwriting pen outside the touch panel is a second characteristic point. For example, "signature feature points" include one or more of a first contact point, a last contact point, a discontinuous contact point, a contact point with a large change in curvature, and the like of the stylus pen with the touch panel. The "signature feature points" also include the points in the stylus motion trajectory corresponding to two discrete contact points where the stylus is farthest from the touch panel.

As will be understood by those skilled in the art, the farthest distance between the stylus and the touch panel during each pen lifting period of the stylus may reflect the writing habits of different users to some extent. For example, in the process of inputting a handwritten signature by a user, when discontinuous strokes are input, the stylus needs to be lifted to move away from the touch panel, wherein the distance between the two strokes, which is the farthest point away from the touch panel, of the stylus driven by different users is different between writing.

The "security level" mentioned in the embodiment of the present invention refers to the security condition of the environment in which the signature authentication system is located. For example, signature authentication is performed in an environment such as a home or a car, and is relatively safe for a user. In a more specific example, a user needs to input a handwritten signature on the touch panel of his personal computer in order to turn on the usage right. When a user holds a personal computer at home or in his car, the environment at home or in his car is less likely to be invaded by an attacker than in other public places, so the security level is relatively high. Specifically, the security levels of different environments in which the signature authentication system is located can be distinguished through "first", "second", "third", and the like. Where "first" may be set to the highest security level, with successive downgrades. For example, the "first safety level" is used in the home or in the car, the "second safety level" is used in the office, and the "third safety level" is used outdoors.

Further, in a relatively secure environment, where the probability of aggressor encroachment is low, a relatively low match rate threshold may be set to better accommodate the needs of the user. Specifically, different matching rate thresholds may be preset according to different security levels. For example, the threshold matching rate is preset to 60% at the first security level. In the second security level, the matching rate threshold is preset to 70%. In the third security level, the threshold matching rate is preset to 80%. It can be understood that the specific security level dividing manner and the setting of the matching rate threshold may be adjusted as needed, and are not described herein.

In addition, in the description of the present application, unless otherwise specified, "first", "second", "third", and the like are used only to distinguish different data, signature feature points, or security levels, and should not be construed as a specific limitation on the data, signature feature points, or security levels.

Fig. 1 is a schematic diagram of a signature authentication system according to an embodiment of the present invention. As shown in fig. 1, includes: a terminal 100 and a stylus pen 200. Among them, the terminal 100 includes a touch panel. A user inputs a handwritten signature on a touch panel of the terminal 100 using the stylus pen 200, and the terminal 100 detects data related to the handwritten signature such as signature image information and pressure information of the stylus pen 200 on the terminal 100; meanwhile, the stylus pen 200 detects data related to a handwritten signature, such as motion trace information of the stylus pen 200 and pressure information of the user on the stylus pen 200, and transmits the data to the terminal 100. The terminal 100 detects the matching rate of the data related to the handwritten signature input by the user and the signature template data by the terminal 100 and the handwriting pen 200, and when the matching rate is not lower than a preset matching rate threshold, the terminal 100 confirms that the handwritten signature input by the user passes the authentication.

In one example, after the authentication of the handwritten signature entered by the user is passed, the terminal 100 may allow the user to continue to access the associated rights of the corresponding function of the terminal 100.

As above, the data related to the handwritten signature entered by the user may include: image information of a signature detected by the terminal 100, and pressure information of a contact point of the stylus pen 200 and the touch panel. And the pressure information of the user on the stylus pen 200 and the motion trail information of the stylus pen 200 in the process of inputting the handwritten signature by the user, which are detected by the stylus pen 200.

In which, for simplicity of explanation, data related to detection of a handwritten signature by the terminal 100 is classified as first signature data. The data related to the detection of the handwritten signature by stylus 200 is classified as second signature data. The stylus pen 200 transmits the second signature data it detects to the terminal 100 through the communication link 300.

According to the signature authentication system provided by the embodiment of the invention, when a user inputs a handwritten signature by using the stylus pen, the terminal detects first signature data, and meanwhile, the stylus pen detects second signature data and sends the second signature data to the terminal. And the terminal judges whether the handwritten signature input by the user passes the authentication or not according to the first signature data, the second signature data and pre-stored signature template data.

It can be understood that, before signature authentication, the user pre-inputs a handwritten signature as a template for comparison and matching. The signature template data is data related to a handwritten signature detected by the terminal 100 and the stylus pen 200 when a user pre-inputs the handwritten signature. The terminal 100 stores the signature template data in the memory, and calls the signature template data stored in the memory in the process of inputting a handwritten signature by a user for authentication.

Specifically, when the terminal 100 compares and matches the data related to the handwritten signature detected by the terminal 100 and the stylus pen 200 with the signature template data, the processor of the terminal 100 may perform feature point data extraction on the data related to the handwritten signature to facilitate comparison. It will be appreciated that the signature template data also corresponds to data relating to signature feature points.

It will be appreciated that the speed at which a user enters a handwritten signature may vary from time to time. For example, the user may take 1S to input the handwritten signature last time and 0.8S to input the handwritten signature next time. But the handwritten signature of each user has the comparable attribute, for example, the signature images corresponding to different signatures of the user are similar. Therefore, the handwritten signatures are compared through the data of the feature points.

In one example, the processor of the terminal 100 may extract a first contact point, a last contact point, a discontinuous contact point, a contact point with a large change in curvature, and the like as the first signature feature point. And extracting data such as the coordinates of a contact point, the pressure of the stylus pen on the touch panel, the coordinates of the stylus pen, the pressure of a user on the stylus pen and the like corresponding to the signature characteristic point as data of the first signature characteristic point. In addition, the processor of the terminal 100 may also use the point where the stylus pen is located in the region other than the touch panel as the signature feature point. For example, the terminal 100 extracts a point at which the stylus pen is farthest from the touch panel within a sampling time interval corresponding to two discontinuous contact points as a second signature feature point. And extracting data such as coordinates of the handwriting pen corresponding to the signature characteristic point and pressure of the user on the handwriting pen as data of a second signature characteristic point.

The user inputs a handwritten signature on the touch panel of the terminal 100 by the stylus pen 200, and the terminal 100 displays a signature image on the display panel. In addition, when the terminal 100 determines that the handwritten signature input by the user passes authentication, it instructs the display panel to display prompt information that the authentication passes.

As shown in FIG. 1, stylus 200 and terminal 100 may facilitate information interaction via communication link 300. Here, the communication link 300 may be one or more of a WiFi network, a USB interface, a bluetooth connection, an infrared connection, or the like.

It should be noted that the stylus pen 200 interacts with the terminal 100. The method comprises the following steps: the stylus pen 200 transmits data related to the handwritten signature it detects to the terminal 100 over the communication link 300 and/or the terminal 100 transmits control information on the sampling time and sampling frequency of the stylus pen 200 to the stylus pen 200 over the communication link 300.

Specifically, the touch panel may detect coordinate information of a contact point of the stylus pen 200 with the touch panel. The pressure information of the stylus pen 200 against the touch panel at the contact point may be detected by integrating a pressure sensor on the touch panel.

Specifically, the stylus pen 200 may detect the motion trace information of the stylus pen 200 by integrating an acceleration sensor, a magnetic field intensity sensor, an angular velocity sensor, and the like. Stylus 200 may detect pressure information of the user on stylus 200 via a pressure sensor.

It is understood that the preset matching rate threshold can be adjusted according to actual needs. Wherein the matching rate threshold may be set according to the security level. The matching rate threshold may also be set directly. In one possible example, the terminal 100 may determine the environment in which the terminal 100 is located by detecting the network to which it is connected. A corresponding security level and a matching rate threshold are further determined.

It can be understood that the information of the pressure of the user on the stylus detected by the stylus reflects the pen-holding strength of the user. The data related to the handwritten signature entered by the user may further include: the pressure area and/or pressure shape information of the stylus pen subjected to the user pressure detected by the stylus pen 200. Wherein the pressed area and/or pressed shape of the stylus pressed by the user reflects the gesture of the user holding the pen (stylus). For example, the user g1 is used to grasp the pen with the thumb and the index finger, and compare the information with the pre-stored pen-holding strength and pen-holding posture of the user g1 to determine whether the pen-holding strength and pen-holding posture match when the user g1 re-inputs the handwritten signature for authentication by pre-storing the information about the pressure applied to the pen when the user g1 grasps the pen with the thumb and the index finger and the pressed area and/or pressed shape of the pen.

Specifically, the pen-holding posture of the user can be obtained by using a pressure sensor or a touch sensor in combination with the above detection manner of the pen-holding strength of the user.

It will be appreciated that the data relating to the handwritten signature entered by the user may also include: acceleration of stylus movement detected by stylus 200. Such as acceleration of the stylus tip.

Specifically, the acceleration of the pen tip of the stylus pen can be obtained by the acceleration sensor described above. And the motion track of the stylus pen can be calculated.

It will be appreciated that the data relating to the handwritten signature entered by the user may also include: distance information of the pressed area of the stylus 200 from the tip of the stylus. The distance between the pressed area of the stylus and the pen end of the stylus reflects pen holding habits of different users. For example, some users prefer to hold the middle of the pen to write. Some users prefer to hold the upper end of the pen for writing and the like.

In other embodiments of the present invention, the security level or the matching rate threshold of the environment in which the terminal 100 is located may be input to the terminal by other users. In a specific application scenario, for example, when a user C transacts related business in a bank, a handwritten signature needs to be input for identity authentication, at this time, other users are bank staff D, and the bank staff D may input a matching rate threshold value of the user C when performing the handwritten signature authentication to the terminal 100 according to actual needs.

In other embodiments of the present invention, the stylus pen 200 may be integrated on the terminal 100, for example, the terminal 100 is provided with a slot, the stylus pen 200 can be inserted into the terminal 100, and the user pulls out the stylus pen 100 and uses it when signing. For simplicity, the embodiment of the present invention is described by taking the stylus pen 200 as an example and separating it from the terminal 100.

In other embodiments of the present invention, the terminal 100 may be a smart phone with a touch screen, or a terminal with a touch screen. In addition, the touch screen/touch panel can be detached from the terminal and is integrated with the touch screen, and at this time, the touch screen can also be called a handwriting board. The signature authentication system will include a touch screen (writing pad), a terminal and a stylus. The touch screen is used for receiving a handwritten signature of a user and detecting information of a signature image, and the touch screen is integrated with a pressure sensor to detect pressure information of a stylus pen. And the touch screen records the related data of the handwritten signature and sends the data to the terminal. The embodiment of the invention is only described by taking the integration of the touch screen and the terminal as an example.

The signature data detected by the embodiment of the invention comprises image information of the signature detected by the terminal, pressure information of the handwriting pen to the terminal, motion trail information of the handwriting pen when a user inputs the signature by using the handwriting pen, and pressure information of the user to the handwriting pen. According to the signature authentication system provided by the embodiment of the invention, in the process of signing by using the stylus pen, more user signature characteristic data are extracted by the stylus pen at the same time, and compared and matched, so that an attacker still needs to simulate the hand action of the user while simulating the handwriting of the user, the difficulty of simulating the signature data by the attacker is increased, and the safety of the signature authentication system is greatly improved.

Correspondingly, the embodiment of the invention also provides a terminal, which is used for realizing the system provided in the embodiment. As shown in fig. 2, the terminal includes: display screen 110, sensors 120, I/O subsystem 130, processor 140, memory 150, communication unit 160, and power supply 170. The various components of the terminal 100 will now be described in detail with reference to fig. 2:

the display 110 is used for receiving a handwritten signature input by the user, displaying a handwritten signature image input by the user or displaying prompt information of a handwritten signature authentication result input by the user, and various menus of the terminal 100. A particular display screen 110 may include a touch panel 111 and a display panel 112.

The touch panel 111, also referred to as a touch screen, touch sensitive screen, or the like, may collect contact or non-contact operations by a user thereon or nearby. For example, the user operates on the touch panel 111 or in the vicinity of the touch panel 111 using any suitable object such as a stylus pen (stylus pen). Alternatively, the touch panel 111 may include two parts of a touch detection device and a touch controller. The touch detection device detects the touch direction and the touch posture of the stylus pen, detects signals brought by touch operation and transmits the signals to the touch controller. The touch controller receives touch information from the touch sensing device and converts it into information that can be processed by the processor 140. In addition, the touch controller can receive and execute commands sent by the processor 140.

In one example, the touch controller converts a touch orientation of a contact point of the stylus pen with the touch panel 111, which is detected by the touch detection device, into coordinate information of the contact point, and transmits the coordinate information of the contact point to the processor 140.

Further, the touch panel 111 may cover the display panel 112, a user may operate on or near the touch panel 111 covered on the display panel 112 according to the content displayed on the display panel 112, the touch panel 111 detects the operation on or near the touch panel and transmits the operation to the processor 140 through the I/O subsystem 130 to determine a user input, and then the processor 140 provides a corresponding visual output on the display panel 112 through the I/O subsystem 130 according to the user input. Although in fig. 2, the touch panel 111 and the display panel 112 are two separate components to implement the input and output functions of the terminal 100, in some embodiments, the touch panel 111 and the display panel 112 may be integrated to implement the input and output functions of the terminal 100.

The I/O subsystem 130, external devices for controlling input and output, may include a display controller 131, a sensor controller 132, and other input device controllers 133. Wherein the display controller 131 receives signals from the display screen 110 and/or transmits signals to the display screen 110. Upon detection of the handwritten signature information input by the user by the display screen 110, the display controller 131 converts the detected handwritten signature information input by the user into interaction with the user interface object displayed on the display screen 110. For example, the display controller 131 converts handwritten signature information input by the user into a handwritten signature image displayed on the display panel 112, thereby realizing human-computer interaction. The sensor controller 132 may receive signals from one or more sensors 120 and/or transmit signals to one or more sensors 120.

The terminal 100 can also include at least one sensor 120, such as a pressure sensor 121 and other sensors 122. Specifically, the pressure sensor 121 is configured to detect pressure information received by the terminal 100. Further, a pressure sensor 121 may be integrated in the display screen 110, detect pressure information of the stylus pen against the touch panel 111, and transmit the information to the processor 140 through the sensor controller 132. Specifically, the pressure sensor 121 is disposed between the touch panel 111 and the display panel 112, or the pressure sensor 121 is overlaid on the touch panel 111, so that the pressure sensor 121 detects pressure information of the stylus pen to the touch panel 111.

Here, the coordinate information of the contact point detected by the touch panel 111 and the pressure information of the stylus pen on the touch panel 111 detected by the pressure sensor 121 may be unified into the first signature data detected by the terminal 100.

The processor 140 is a control center of the terminal 100, connects various parts of the entire terminal using various interfaces and lines, performs various functions of the terminal 100 and processes data by running or executing software programs and/or modules stored in the memory 150 and calling data stored in the memory 150, thereby monitoring the terminal 100 as a whole. Optionally, processor 140 may include one or more processing units. Preferably, the processor 140 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 140.

In one example, during the user's input of a handwritten signature, the display controller 131 and the sensor controller 132 transmit the detected first signature data to the application processor. Meanwhile, the stylus pen 200 detects the second signature data and transmits it to the terminal 100. The second signature data sent by the stylus 200 received by the modem processor is sent to the application processor. The application processor determines whether the handwritten signature authentication input by the user passes or not according to the first signature data and the second signature data of the handwritten signature by operating the software program in the memory 150 and calling the signature template data in the memory 150. And the application processor matches and compares the first signature data and the second signature data with the signature template data to obtain corresponding matching rates. When the matching rate is not lower than the preset matching rate threshold, the application processor determines that the signature authentication is passed, and instructs the display screen 110 to display prompt information that the signature authentication is passed.

And a communication unit 160 for implementing information interaction between the terminal 100 and an external network or device. A wireless communication module and/or a communication interface may be included. The wireless communication module may be used for receiving and transmitting signals during information transmission and reception, for example, a radio frequency circuit or a WiFi module. The communication interface may be used for directly connecting with an external device, so as to enable the terminal 100 to interact information with the external device. Such as a USB interface. In addition, the communication unit 160 may further include an infrared module, a bluetooth module, and other components that enable information interaction between the terminal 100 and an external network or device, which is not specifically limited herein.

The terminal 100 further includes a power supply 170 (e.g., a battery) for supplying power to the various components, and preferably, the power supply 170 may be logically coupled to the processor 140 via a power management system, such that functions of managing charging, discharging, and power consumption are performed via the power management system.

The terminal 100 may also include other input devices 180, the other input devices 180 being coupled to other input device controllers 133 of the I/O subsystem 130 for interacting with information from the processor 140 under the control of the other input device controllers 133. And will not be described in detail herein.

In a specific example, when a user inputs a handwritten signature on the display 110 of the terminal 100 using the stylus pen 200, the touch detection device of the touch panel 111 detects an orientation signal of a contact point of the stylus pen 200 and the touch panel 111, and the touch controller of the touch panel 111 converts the orientation signal of the contact point into coordinate information and transmits the coordinate information to the processor 140 through the display controller 131. The pressure sensor 121 detects pressure information of the stylus pen 200 against the touch panel 111 at the above-mentioned contact point, and transmits the information to the processor 140 through the sensor controller 132. It is to be understood that the coordinate information of the contact point and the pressure information of the contact point may be referred to as first signature data. In addition, after the display screen 110 detects a handwritten signature input by the user, the display controller 131 converts the detected handwritten signature input by the user into a signature image that can be displayed on the display screen 110 for the user to view.

The terminal 100 receives the second signature data detected by the stylus pen 200 through the communication unit 160. Wherein the second signature data includes: when the user inputs the handwritten signature through the stylus pen 200, the motion trajectory information of the stylus pen, the acceleration of the pen end of the stylus pen, the pressed area and/or pressed shape information of the stylus pen under the user pressure, and the pressure information of the user on the stylus pen 200, which are detected by the stylus pen 200, are related information. The processor 140 compares and matches the first signature data and the second signature data with signature template data pre-stored in the memory 150, and calculates a matching rate. The processor 140 compares the calculated matching rate with a matching rate threshold value pre-stored in the memory 150, and when the calculated matching rate threshold value is not lower than the pre-stored matching rate threshold value, the processor 140 determines that the handwritten signature of the user passes the authentication. The processor 140 instructs the display panel 112 to display prompt information that the user has passed the authentication of the handwritten signature.

Specifically, the terminal 100 processor 140 may extract data of the signature feature point through the first signature data and the second signature data. And matching and comparing the extracted data of the signature characteristic points with the corresponding data of the signature characteristic points in the signature template, and calculating the matching rate. The signature characteristic points comprise a first signature characteristic point and a second signature characteristic point. The data of the signature feature points include data of the first signature feature point and data of the second signature feature point. For a specific signature feature point and a method for extracting data thereof, reference may be made to the detailed description in fig. 4.

It should be noted that before the user uses stylus 200 to input the handwritten signature, the user or another user may send an instruction indicating the identity information of the user to processor 140, and processor 140 may call the signature template data of the user from memory 150 according to the instruction indicating the identity information of the user.

Specifically, the instruction indicating the identity information of the user may be information such as an identity card number of the user, a job number of the user, and the like. The memory 150 pre-stores signature template data of a plurality of users, and the signature template data of each user carries identity information of the user. The processor 140, after receiving the instruction indicating the identity information of the user, queries the memory 150 for the signature template data of the user according to the identity information of the user. Wherein the signature template data of each user carries identity information of the user.

It will be appreciated that the signature template data for each user may comprise a plurality of such data, taking into account the inherent differences in the handwritten signature each time the user enters. That is, when the user pre-inputs a handwritten signature, the user may input the handwritten signature (template) a plurality of times, and the terminal 100 and the stylus pen 200 detect data of each handwritten signature (template) and store the data one by one. At the stage of inputting a handwritten signature by a user for authentication, the processor 140 compares and matches signature data of the authentication stage detected by the terminal 100 and the stylus pen 200 with a plurality of signature template data of the user one by one, selects the maximum matching rate as the final comparison matching rate, and judges whether the signature authentication of the user passes or not according to a preset matching rate threshold.

It is understood that the signature template data also includes first signature (template) data detected by the terminal 100 and second signature (template) data detected by the stylus pen 200. In addition, the signature template data may include data of extracted corresponding signature feature points. For a specific signature feature point and a method for extracting data thereof, reference may be made to the detailed description in fig. 4.

Correspondingly, the embodiment of the invention also provides a stylus pen for realizing the system provided in the embodiment. As shown in fig. 3, the stylus pen includes: sensor unit 210, communication unit 220, processor 230, memory 240, power supply 250, etc. The following describes the components of stylus 200 in detail with reference to fig. 3:

a sensor unit 210 for detecting signature data related to a handwritten signature input by the user using the stylus pen 200 on the touch panel 111 of the terminal 100. Specifically, the sensor unit 210 may include an acceleration sensor 211, a magnetic field strength sensor 212, an angular velocity sensor 213, a pressure sensor 214, and other sensors 215.

In one possible embodiment, acceleration sensor 211 may be used to detect acceleration of the tip of stylus 200, magnetic field strength sensor 212 may be used to detect the magnetic field strength of stylus 200, and angular velocity sensor 213 may be used to detect the angular velocity of stylus 200. Further, the motion trajectory information of the stylus pen 200 may be obtained according to the variation information of the acceleration, the angular velocity, and the magnetic field strength of the stylus pen 200. Pressure sensor 214 may be used to detect pressure information of the user on stylus 200.

It is noted that other sensors 215 may include a gyroscope, a gravity sensor, a WiFi positioning sensor, or an infrared positioning sensor. The acceleration sensor 211, the magnetic field strength sensor 212, and the angular velocity sensor 213 for detecting the motion trace information of the stylus pen 200 may be replaced by one or more of the other sensors 215. The embodiment of the present invention does not specifically limit the sensor used for detecting the motion trajectory data of the stylus pen 200. It is understood that any sensor or instrument for detecting the motion trace of the stylus shall fall within the scope of the embodiments of the present invention.

The sensor unit 210 may also detect information on a pressed area and pressed shape of the stylus pen by the user's pressure, information on a distance of the pressed area of the stylus pen from the tip of the stylus pen, and the like, through related sensors. The associated sensors herein may include touch sensors. The information can be used as one or more of the second signature data to reflect pen holding habits of different users. Through the comparison of the characteristic information, the simulation difficulty of an attacker is increased.

And a communication unit 220, configured to connect with the communication unit 160, and implement information interaction between the stylus pen 200 and the terminal 100. The communication unit 220 may also include a communication module and/or a communication interface corresponding to the communication unit 160. For example, the communication unit 160 includes a WiFi module 1, the communication unit 220 includes a corresponding WiFi module 2, and the terminal 100 and the stylus pen 200 establish a communication connection through the WiFi module 1 and the WiFi module 2.

The processor 230, which is used to run or execute software programs and/or modules stored in the memory 240, performs the function of converting the relevant signature data detected by the sensor unit 210 into information that can be processed by the terminal 100. For example, the processor 230 converts acceleration information, magnetic field strength information, and angular velocity information of the stylus pen 200 detected by the acceleration sensor 211, the magnetic field strength sensor 212, and the angular velocity sensor 213 into motion trace information of the stylus pen that can be processed by the terminal 100, and transmits the motion trace information to the terminal 100.

In addition, the processor 230 is also used to control the sampling time and sampling frequency of the sensor unit 210 through control information. It will be appreciated that the above control information may also be sent by terminal 100 to control the sampling time and sampling frequency of stylus 200 to be synchronized with the touch panel and sensors of terminal 100.

A memory 240 for storing relevant software and/or modules, such as software and/or modules for executing the conversion of the relevant signature data detected by the sensor unit 210 into information that can be processed by the processor 140. And is further configured to store data detected by the sensor unit 210, and send the data to the processor 230 after sampling is finished, so that the processor 230 converts the data detected by the sensor unit 210 into second signature data that can be processed by the terminal.

Stylus 200 also includes a power supply 250 for powering the various components.

In a specific example, when the user inputs a handwritten signature on the touch panel 111 of the terminal 100 using the stylus pen 200, the stylus pen 200 detects information such as acceleration, magnetic field intensity, and magnetic field intensity of the stylus pen 200 through the acceleration sensor 211, the magnetic field intensity sensor 212, and the angular velocity sensor 213. Pressure information of the user on stylus 200 is provided via pressure sensor 214.

The processor 230 of the stylus pen 200 converts the acceleration, magnetic field strength, etc. of the stylus pen 200 into the motion trace information of the stylus pen 200. The motion trajectory information of the stylus pen 200 and the pressure information of the user on the stylus pen 200 are second signature data. The handwriting pen 200 further extracts the motion trail information of the handwriting pen 200, the acceleration of the handwriting pen 200, the pressed area and/or pressed shape information of the handwriting pen 200 pressed by the user and the pressure information of the handwriting pen 200 by the user at the same time through the processor 230, packages the extracted information into a data packet carrying information at the corresponding time, and sends the data packet to the terminal 100 through the communication unit 220.

It should be noted that the stylus pen 200 receives the control information of the sampling time and the sampling frequency transmitted by the terminal 100 through the communication unit 220, and ensures the real-time correspondence between the first signature data and the second signature data. For example, the sampling time of the first contact point of the stylus pen 200 and the touch panel 111 of the terminal is 0ms, the terminal 100 sends the control information so that the sampling time of the stylus pen 200 at this time is also 0ms, and the sampling frequency of the stylus pen 200 and the terminal 100 are both controlled to be 0.2 ms/time. It can be understood that, in the case that the sampling time and the sampling frequency of the terminal 100 and the stylus pen 200 are synchronized, it is very difficult for an attacker to simulate the handwriting of the user and the pressure of the stylus pen held by the user on the touch panel, and simultaneously simulate the information such as the hand motion of the user and the pressure of the stylus pen held by the user.

Therefore, by applying the signature authentication system, the terminal and the handwriting pen, signature template data are added, the synchronization of sampling time and sampling frequency of the handwriting pen and the terminal is controlled, more user signature characteristic data are extracted by the handwriting pen in the process of using the handwriting pen for signature by a user, and compared and matched, so that an attacker still needs to simulate the hand action of the user while simulating the handwriting of the user, the difficulty of simulating the signature data by the attacker is increased, and the safety of the signature authentication system is greatly improved.

Accordingly, the coordinate system and signature schematic of the signature authentication system provided by the embodiment of the present invention can be seen in fig. 4.

As shown in fig. 4, the user holds the stylus pen and inputs a handwritten signature on the touch panel. The position where the stylus pen is in contact with the touch panel may be referred to as a point of contact. The touch panel detects the orientation of a contact point and displays the contact point through a display panel integrated with the touch panel. For example, the display panel is originally displayed in white, and when a contact point is detected, the contact point is displayed in black.

The user drives the stylus pen to move on the touch panel, and all contact points of the stylus pen and the touch panel form a signature image of the user. The "king" in fig. 4 is the handwritten signature image of the user.

When the user holds the stylus pen and drops the pen, a contact point, such as the contact point shown in fig. 4, exists between the stylus pen and the touch panel. Between writing different strokes or different words, the user lifts the stylus and moves the stylus from the previous point of contact to the next point of contact that is not contiguous with the previous point of contact, in an area outside the touch panel. When the user holds the stylus pen to lift the pen, the stylus pen may trace a motion track in an area outside the touch panel, as shown in fig. 4.

Therefore, the first signature feature point may be set as a pen-down point (a touch point) of the stylus pen, and the second signature feature point may be set as a point (a point other than the touch point) corresponding to the pen-up of the stylus pen.

In the process of inputting a handwritten signature by a user, the touch panel converts the detected touch position of the contact point into coordinate information of the contact point. The touch panel is integrated with a pressure sensor for detecting pressure information of the stylus pen received at the contact point. Meanwhile, the stylus pen integrates related sensors to detect the motion trace information of the stylus pen and the pressure information of the user on the stylus pen. For example, the handwriting pen obtains the motion track information of the handwriting pen through the acceleration sensor, the magnetic field intensity sensor and the angular velocity sensor, and the pressure sensor detects the pressure information of the user on the handwriting pen.

Therefore, coordinate information of a contact point detected by the touch panel and the pressure sensor integrated thereon and pressure information of the stylus pen against the touch panel may be set as the first signature data, and motion trajectory information of the stylus pen detected by the relevant sensor and pressure information of the user against the stylus pen may be set as the second signature data.

Therefore, the data corresponding to the first signature feature point may include: the coordinate information of the contact point, the pressure information of the stylus pen on the touch panel at the contact point, the coordinate information of the pen end of the stylus pen and the pressure information of the user on the stylus pen. It is understood that, if the coordinate information of the contact point and the coordinate information of the pen tip of the stylus pen are in the same coordinate system, one of them may be used. The data corresponding to the second signature feature point may include: coordinate information of the pen end of the stylus pen and pressure information of the user on the stylus pen. In particular, when the stylus pen is lifted, the touch panel and the pressure sensor integrated thereon do not detect information about the point of contact. That is, if the stylus pen is lifted in the time period from time T1 to time T2, there is no detected first signature data in the time period.

In one possible example, the coordinate system of the touch panel is shown as o in FIG. 4₁x₁y₁z₁Shown by₁x₁y₁z₁The x-axis and the y-axis of the coordinate system are in the plane of the touch panel, and the z-axis is perpendicular to the plane of the touch panel. The coordinate system of the stylus is shown in figure 4,

o₂x₂y₂z₂the z-axis of the coordinate system is the straight line where the stylus pen is located, and the x-axis and the y-axis are on the plane perpendicular to the stylus pen.

When the touch panel detects a contact point, the touch panel detects a contact point at o₁x₁y₁z₁And recording coordinate information in the coordinate system. But it is contemplated that the signature location may differ from the origin each time the user enters the signature. Therefore, the processor of the terminal can inform the received coordinates of the contact pointPreprocessing the coordinate system o₁x₁y₁z₁The data in (1) is transformed into a new coordinate system, which needs to be referential to the handwritten signature image every time the user enters. For example, the new coordinate system may be the user's handwritten signature with the center as the origin and the two midpoints of the signature as the x-axis and the y-axis. The "median line" of the signature refers to the two symmetrical lines of the signature image. In particular, can be obtained by para-o₁x₁y₁z₁And solving the average value of the y coordinates of the contact points with the same x coordinate in the coordinate system to obtain an average point under the x coordinate, and solving a median line of the signature image according to all the average points under the same x coordinate in the contact points. The other bisector passes through the center point of the signature and is perpendicular to the other bisector.

It can be understood that the signature image input by the user at each time is fixed and contrastable with respect to the central point and the median line of the image. Therefore, the data in the signature template is similarly transformed in accordance with the new coordinate system as described above.

Touch panel in coordinate system o₁x₁y₁z₁Coordinates of the contact point are detected. It is understood that the z-axis coordinate of the contact point within the touch panel is 0. The coordinates of the contact point can be represented using (a1, b1, 0). Stylus pen in coordinate system o₂x₂y₂z₂The motion trail of the stylus pen is detected, and the motion trail of the stylus pen can be represented by the motion trail of the pen end of the stylus pen. The coordinates of the pen tip of the stylus pen can be (a2, b2, c).

It should be noted that, when the stylus pen is dropped, and there is a contact point between the pen end of the stylus pen and the touch panel, if the coordinates of the contact point are in the same coordinate system, the coordinates of the pen end of the stylus pen should be the same. During actual detection, the same contact point or the corresponding pen end of the stylus is at o₁x₁y₁z₁And o₂x₂y₂z₂The coordinates in the two coordinate systems may be different.

Can transform o by coordinate₂x₂y₂z₂Coordinate systemTo a coordinate system o₁x₁y₁z₁Specifically, the coordinate transformation may analyze the position relationship between the two coordinate systems using information such as the coordinate relationship between the same contact point or the corresponding pen tip of the stylus pen in the two coordinate systems, and perform coordinate transformation on one of the two coordinate systems.

Furthermore, the data in the signature feature point may include a plurality of data, for example, the contact point is S1, for example, S1 may be the first contact point between the stylus and the touch panel. The signature feature data E corresponding to S1 includes: coordinates of the point of contact (a1, b1,0), stylus pressure against the touch panel P1, coordinates of the stylus (a2, b2, c), user pressure against the stylus P2. Correspondingly, the signature characteristic data e included in the signature template corresponding to the signature characteristic point S1 is: coordinates of the point of contact (m1, n1,0), stylus pressure to the touch panel D1, coordinates of the stylus (m2, n2, q), user pressure to the stylus D2.

The matching rates of the data E and the data E include an average or weighted average of four sets of data matching rates of (a1, b1,0) and (m1, n1,0), P1 and D1, (a2, b2, c) and (m2, n2, q), P2 and D2. The matching rate of the coordinates of the two points can be obtained by the matching rate of the distance value between the two coordinates and the origin, or by the matching rate of the corresponding coordinate values and then the weighting and averaging.

In addition, the data of the signature feature points may include more than one, and the matching rate of all the signature feature points and the signature template data may be obtained by averaging or weighted averaging the matching rate of all the signature feature points corresponding to the data of each feature point. Wherein, the weighting value can be set according to actual needs.

In addition, the movement track of the pen end of the stylus pen acquired by the stylus pen and the coordinates of the contact point acquired by the touch panel can be subjected to unified coordinate system transformation, and the transformed movement track of the pen end of the stylus pen is projected. And extracting the data of the characteristic points of the projected motion trail as the data of the signature characteristic points. See in particular the following description:

in one example, coordinates of a stylus are being writtenIs o of₂x₂y₂z₂Conversion to coordinate system o of touch panel₁x₁y₁z₁Then, the pen tip of the stylus pen can be positioned in the coordinate system o₂x₂y₂z₂The motion track data in (1) are correspondingly converted into the coordinate system o₁x₁y₁z₁The motion trajectory data of (1). Is provided at o₁x₁y₁z₁In the coordinate system, the xy plane where the touch panel is located is a first plane, and a curve formed by contact points in the signature image is set as a first motion track of the pen end of the stylus pen on the first plane. And projecting the converted (three-dimensional) motion track of the pen end of the stylus pen on a plane where the touch panel is located, and removing a part which is superposed with the first motion track after projection to obtain a second motion track of the pen end of the stylus pen on the first plane.

Then, the first signature feature point is a feature point extracted from the first motion trajectory of the stylus pen. At this time, the coordinate information of the first signature feature point may be expressed in two-dimensional coordinates in the first plane. It will be appreciated that if the stylus is projected in a first plane, a new second signature feature point may be extracted from a second motion trajectory of the stylus. For example, the new second signature feature point may be a point with a large curvature change in each discontinuous curve corresponding to the second motion trajectory. Therefore, the data corresponding to the new second signature feature point is the two-dimensional coordinates of the point on the first plane, the pressure information of the user on the stylus pen, the acceleration of the pen end of the stylus pen, the pressed area and the pressed shape of the stylus pen under the pressure of the user, and the like.

It will be appreciated that once the two coordinate systems are unified, the coordinates of the first signature feature point will coincide with the coordinates of the new second signature feature point.

In another example, the coordinate system o of the stylus is₂x₂y₂z₂Conversion to coordinate system o of touch panel₁x₁y₁z₁Then, the pen tip of the stylus pen can be positioned in the coordinate system o₂x₂y₂z₂Corresponding rotation of motion trajectory data inChange to being in the coordinate system o₁x₁y₁z₁The motion trajectory data of (1). Is provided at o₁x₁y₁z₁In the coordinate system, the xy plane where the touch panel is located is a first plane, and a curve formed by contact points in the signature image is set as a first motion track of the pen end of the stylus pen on the first plane. Two planes perpendicular to the first plane are set as a second plane and a third plane. The second plane and the third plane are perpendicular to each other, and the second plane and the third plane share the same origin and the same coordinate axis with the first plane. And respectively projecting the converted (three-dimensional) motion tracks of the pen end of the handwriting pen on a first plane, a second plane and a third plane, and removing the part which is superposed with the first motion track after projection to obtain second motion tracks of the pen end of the handwriting pen on the three planes.

Then, the first signature feature point is a feature point extracted from the first motion trajectory of the stylus pen. At this time, the coordinate information of the first signature feature point may be expressed in two-dimensional coordinates in the first plane. For example, the data corresponding to the first signature feature point includes: the coordinates (m1, n1) of the point of contact in the first plane, the stylus pressure to the touch panel D1, and the user pressure to the stylus D2. The data of the acceleration d1 of the pen end of the stylus, the pressed area S1 of the stylus, the distance T1 of the pressed area of the stylus from the pen end of the stylus and the like can also be included.

It will be appreciated that if the stylus' motion trajectory is projected in three planes, a new second signature feature point may be extracted from the second stylus motion trajectory. For example, the new second signature feature point may be a point with a large curvature change in each discontinuous curve corresponding to the second motion trajectory. Therefore, the data corresponding to the new second signature feature point is the two-dimensional coordinate of the point on the first plane, the two-dimensional coordinate on the second plane or the two-dimensional coordinate on the third plane, the pressure information of the user on the stylus pen, the acceleration of the pen end of the stylus pen, the pressed area and pressed shape of the stylus pen under the pressure of the user, and the like.

For example, the data corresponding to the new second signature feature point includes: the coordinates (m2, n2) of the feature point in the first plane or the coordinates (m3, q1) of the feature point in the second plane or the coordinates (n3, q2) of the feature point in the second plane, the pressure D2 of the stylus pen on the touch panel, and the pressure D4 of the user on the stylus pen. The data of the acceleration d2 of the pen end of the stylus, the pressed area S2 of the stylus, the distance T2 of the pressed area of the stylus from the pen end of the stylus and the like can also be included. Wherein, the feature data of the projection points in different planes can be respectively extracted and compared.

Specifically, if a coordinate system-transformation signature authentication comparison scheme for projecting the motion trajectory of the stylus pen is adopted, when the signature template data is prestored, corresponding transformation is performed on the signature template data pre-input by the detected user, and the corresponding signature feature points and signature feature data are extracted and stored as the signature template data.

The embodiment of the invention can also transform the two coordinate systems of the stylus pen and the touch panel of the terminal, and project the motion track of the stylus pen on the plane where the touch panel is located, thereby avoiding the situation that the coordinate data of the same corresponding characteristic point in the two coordinate systems are matched and compared in the original two coordinate systems. The embodiment of the invention also projects the motion track of the stylus on two planes vertical to the plane where the touch panel is located, simplifies the three-dimensional coordinate comparison into a two-dimensional coordinate comparison mode, and simplifies the complexity of signature data comparison and matching. It should be noted that fig. 4 is only a more intuitive schematic form of the signature authentication system, and is not used as any limitation to the embodiment of the present invention.

The following describes the signature authentication method according to an embodiment of the present invention in detail with reference to fig. 5, where fig. 5 is a signaling interaction diagram of a signature authentication method according to an embodiment of the present invention, and an implementation subject is a terminal in the embodiment of the present invention. As shown in fig. 5, this embodiment specifically includes the following steps:

in step S101, a touch panel of a terminal detects a handwritten signature input by a user through a stylus pen.

And step S102, the terminal sends control information to the handwriting pen so as to control the sampling time and the sampling frequency of the handwriting pen to be synchronous with the terminal.

The terminal sends control information to the stylus pen through the communication unit 1.

The sampling time and the sampling frequency of the terminal and the handwriting pen are kept synchronous with the terminal, so that an attacker still needs to simulate the hand action of the user while simulating the handwriting of the user, the difficulty of simulating signature data by the attacker is increased, and the safety of the signature authentication system is greatly improved.

It should be noted that, the user handwriting herein refers to image information of the user signature, and specifically, the handwriting may refer to coordinate information of each point in the signature image. Additionally, the handwriting may also include pressure information of the stylus on the touch panel at each point in the signature image. Wherein each point in the signature image corresponds to a point of contact of the stylus pen with the touch panel.

It should be noted that the hand motion of the user refers to the motion trajectory information when the user drives the stylus pen to move during the process of inputting a signature by using the stylus pen. In addition, the hand motion may further include pressure information of the user on the stylus pen, information of a pressed area and a pressed area shape of the stylus pen subjected to the pressure of the user, information of a distance from the pressed area to a pen tip of the stylus pen, and the like.

It can be understood that the handwriting of the user and the hand motion of the user both represent the characteristic information in the process of inputting the signature by the user, and the authentication result of the signature input by the user is determined according to the enumerated characteristic information, so that the safety and reliability of the signature authentication system can be improved.

In step S103a, the touch panel collects coordinate information of a contact point between the stylus pen and the touch panel, and the pressure sensor collects pressure information of the stylus pen on the touch panel at the contact point.

Wherein, the contact point of the stylus pen and the touch panel forms a signature image.

In step S103b, the sensor unit of the stylus collects information of the motion trace of the stylus and information of the pressure of the user on the stylus.

The information such as the acceleration, the magnetic field intensity and the magnetic field intensity of the handwriting pen can be detected through the acceleration sensor, the magnetic field intensity sensor and the angular velocity sensor. Pressure information of the user on the stylus via the pressure sensor.

Furthermore, other sensors can be heard to detect the pressed area and the pressed area shape information of the stylus pen pressed by the user, and the distance information of the pressed area from the pen end of the stylus pen. Other sensors herein may also include pressure sensors, etc.

In step S104a, the processor of the terminal converts the data collected in step S103a into first signature data.

The processor of the terminal corresponds the data detected by the touch panel and the pressure sensor one by one according to the acquisition time, namely the coordinate information of a contact point and the pressure information of the stylus pen at the contact point on the touch panel under one acquisition time.

In step S104b, the stylus processor converts the data collected in step S103b into second signature data.

The processor of the handwriting pen converts the information of the acceleration, the magnetic field intensity and the like of the handwriting pen into the motion trail information of the handwriting pen.

The processor of the handwriting pen corresponds the motion track information of the handwriting pen and the pressure information of the user to the handwriting pen one by one according to the acquisition time, namely the coordinate information of the corresponding handwriting pen in one acquisition time and the pressure information of the user to the handwriting pen in the acquisition time.

In addition, in the case where the data acquired in step S103b further includes other information, the data corresponding to each acquisition time described above is added accordingly.

And step S105, the handwriting pen sends the second signature data to the terminal.

The stylus pen transmits the second signature data to the terminal through the communication unit 2.

And step S106, the processor of the terminal obtains the data of the first signature characteristic point and the data of the second signature characteristic point according to the first signature data and the second signature data.

And the signature corresponds to the first signature characteristic point and the second signature characteristic point. The first signature feature point comprises at least one point in a set of contact points, and the second signature feature point comprises at least one point in a set of points in a motion trajectory of an area outside the touch panel.

The data corresponding to the first signature feature point comprises: coordinate information of a contact point corresponding to the first signature characteristic point, pressure information of the stylus pen on the touch panel at the contact point corresponding to the first signature characteristic point, position information of the stylus pen when the sampling time of the position information of the stylus pen is the same as that of the first signature characteristic point, and pressure information of a user on the stylus pen; wherein, the position information of the handwriting pen is obtained through the track information of the handwriting pen.

The data corresponding to the second signature feature point comprises: and the position information of the handwriting pen corresponding to the second signature characteristic point and the pressure information of the user on the handwriting pen.

In addition, when the data collected in step S103b further includes other information, the data corresponding to the second signature feature point further includes: the method comprises the steps of detecting information of the pressed area and the shape of the pressed area of the stylus pen when a user signs a signature on the touch panel through the stylus pen by the stylus pen, and detecting information of the distance between the pressed area and the pen end of the stylus pen.

Specifically, the first signature feature point specifically includes: a first contact point, a last contact point, a discontinuous contact point, or one or more of a contact point having a large change in curvature.

Specifically, the second signature feature point specifically includes one or more of the following points: the point with the largest curvature in the curve corresponding to the motion trail of each discontinuous stylus pen in the area above the touch panel or the point with the farthest distance from the touch panel in the curve corresponding to the motion trail of each discontinuous stylus pen in the area above the touch panel.

In addition, the movement track of the pen end of the stylus pen and the coordinates of the contact point acquired by the touch panel can be subjected to unified coordinate system transformation, and the transformed movement track of the pen end of the stylus pen is projected. And extracting the feature points of the projected motion trail and the data of the signature feature points as the data of new signature feature points. Specifically, refer to the description in fig. 4, which is not described herein.

And step S107, comparing the data of the first signature characteristic point and the data of the second signature characteristic point with pre-stored signature template data by a processor of the terminal to obtain a matching rate.

The signature template data is related to a pre-input handwritten signature detected by the terminal and the stylus pen when the handwritten signature is pre-input before the user inputs the handwritten signature for authentication. The terminal stores the signature template data in the memory, and calls the signature template data stored in the memory in the process of inputting the handwritten signature by the user for authentication.

The pre-input of the handwritten signature means that some template data are stored before signature authentication of a user and are used as a basis for comparison during signature authentication.

And step S108, comparing the matching rate with a pre-stored matching rate threshold value by the processor of the terminal, and indicating the display panel to display prompt information that the user inputs the handwritten signature for authentication when the matching rate is not lower than the pre-stored matching rate threshold value.

The matching rate threshold value can be preset by the terminal and is directly called from the memory when the user inputs the signature authentication.

In addition, the matching rate threshold value can be adjusted according to the actual environment of the terminal. At this time, the terminal can determine its environment through the network to which its communication unit 1 is connected. And determining the security level of the environment where the terminal is located according to the environment where the terminal is located, and calling the matching rate threshold value under the security level from the memory. The storage of the terminal stores a list of environments corresponding to different networks, a list of security levels corresponding to different environments, and a list of matching rate thresholds corresponding to different security levels. Further, a list of matching rate thresholds corresponding to different networks or environments may be stored directly. The user can invoke their corresponding match rate threshold directly through the network or environment.

According to the signature authentication method, the terminal, the handwriting pen and the system provided by the embodiment of the invention, the terminal and the handwriting pen simultaneously detect the related data of the signature, the related data of the signature is compared and matched with the pre-stored signature template data, and whether the signature authentication passes or not is determined according to the matching rate.

In the embodiment of the invention, in the process that the user inputs the handwritten signature on the touch panel of the terminal by using the stylus pen, more user signature characteristic data are extracted by the stylus pen, and compared and matched, so that an attacker still needs to simulate the hand action of the user while simulating the handwriting of the user, the difficulty of simulating the signature information of the user by the attacker is increased, and the safety of the signature authentication system is greatly improved.

The embodiment of the invention can also set different matching rate thresholds according to the environment of the terminal, and has good application prospect. Meanwhile, the embodiment of the invention provides that a user can prestore a plurality of signature templates in advance, so that the authentication failure rate caused by human factors can be reduced, and the user has higher flexibility in inputting the signature.

The embodiment of the invention can also transform the two coordinate systems of the stylus pen and the touch panel of the terminal, and project the motion track of the stylus pen on the plane where the touch panel is located, thereby avoiding the situation that the coordinate data of the same corresponding characteristic point in the two coordinate systems are matched and compared in the original two coordinate systems. The embodiment of the invention also projects the motion track of the stylus on two planes vertical to the plane where the touch panel is located, simplifies the three-dimensional coordinate comparison into a two-dimensional coordinate comparison mode, and simplifies the complexity of signature data comparison and matching.

Those of skill would further appreciate that the various illustrative components and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It will be understood by those skilled in the art that all or part of the steps in the method for implementing the above embodiments may be implemented by a program, and the program may be stored in a computer-readable storage medium, where the storage medium is a non-transitory medium, such as a random access memory, a read only memory, a flash memory, a hard disk, a solid state disk, a magnetic tape (magnetic tape), a floppy disk (floppy disk), an optical disk (optical disk), and any combination thereof.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method of signature authentication, the method comprising:

when a user signs on a touch panel of a terminal through a handwriting pen, the terminal detects first signature data, wherein the first signature data comprises coordinate information of a contact point of the handwriting pen and the touch panel and pressure information of the handwriting pen on the touch panel at the contact point; the terminal receives second signature data sent by the stylus pen, wherein the second signature data comprise motion track information of the stylus pen and pressure information of the user on the stylus pen, which are detected by the stylus pen when the user signs on the touch panel through the stylus pen;

the signature corresponds to a first signature characteristic point and a second signature characteristic point, the first signature characteristic point comprises at least one point in a set formed by the contact points, and the second signature characteristic point comprises at least one point in a set of points of the handwriting pen in the motion track of the area outside the touch panel;

extracting data corresponding to the first signature characteristic point and the second signature characteristic point from the first signature data and the second signature data;

matching and comparing the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to obtain a matching rate;

and when the matching rate is not lower than a preset matching rate threshold value, the signature passes the authentication.

2. The method of claim 1, wherein the sampling time and sampling frequency of the first signature data and the second signature data remain synchronized.

3. The method of claim 1, wherein the data corresponding to the first signature feature point comprises: coordinate information of a contact point corresponding to the first signature feature point, pressure information of a handwriting pen on the touch panel at the contact point corresponding to the first signature feature point, position information of the handwriting pen when the sampling time of the handwriting pen is the same as the sampling time of the first signature feature point, and pressure information of a user on the handwriting pen;

and obtaining the position information of the handwriting pen through the motion trail information of the handwriting pen.

4. The method of claim 3, wherein the data corresponding to the second signature feature point comprises: and the position information of the handwriting pen corresponding to the second signature characteristic point and the pressure information of the user on the handwriting pen.

5. The method of claim 1 or 4, wherein the second signature data further comprises: the method comprises the steps that the acceleration of the handwriting pen, the information of the pressed area and the shape of the pressed area of the handwriting pen under the pressure of a user and the information of the distance between the pressed area of the handwriting pen and the pen end of the handwriting pen are detected when the user signs on the touch panel through the handwriting pen.

6. The method of claim 1, wherein the first signature feature points specifically include one or more of: the first contact point, the last contact point, a discontinuous contact point or a contact point with a large change in curvature.

7. The method of claim 1, wherein the second signature feature points specifically include one or more of: the point with the largest curvature in a curve corresponding to each discontinuous segment of the motion trail of the stylus pen in the area above the touch panel or the point with the farthest distance from the touch panel in the curve corresponding to each discontinuous segment of the motion trail of the stylus pen in the area above the touch panel.

8. The method according to claim 1 or 2, wherein the matching the first signature data and the second signature data with pre-stored signature template data to obtain a matching rate comprises:

extracting a first signature feature point from the contact point;

projecting the motion track of the pen end of the stylus pen on a first plane where the touch panel is located to obtain a first motion track of the pen end of the stylus pen; projecting the motion trail of the pen end of the stylus pen on a second plane and a third plane which are perpendicular to the first plane to obtain a second motion trail and a third motion trail of the pen end of the stylus pen, wherein the second plane is perpendicular to the third plane;

extracting a second signature characteristic point from at least one of the first motion track, the second motion track and the third motion track;

and matching and comparing the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to obtain a matching rate.

9. The method of claim 1, wherein the matching rate threshold is preset according to an environment in which the terminal is located.

10. A method of signature authentication, the method comprising:

when a user signs on a touch panel of a terminal through a handwriting pen, the handwriting pen detects second signature data, and the second signature data comprises motion track information of the handwriting pen and pressure information of the user on the handwriting pen;

the handwriting pen sends the second signature data to a terminal so that the terminal extracts data corresponding to a first signature characteristic point and a second signature characteristic point from the first signature data and the second signature data, matches and compares the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to determine whether the signature authentication passes or not, the first signature data includes coordinate information of a contact point of a stylus pen with the touch panel and pressure information of the stylus pen against the touch panel at the contact point, the signature corresponds to the first signature feature point and the second signature feature point, the first signature feature point including at least one point in the set of contact points, the second signature feature point comprises at least one point of the set of points in the motion trajectory of the stylus in an area outside the touch panel.

11. The method of claim 10, wherein the second signature data further comprises: the method comprises the steps that the acceleration of the handwriting pen, the information of the pressed area and the shape of the pressed area of the handwriting pen under the pressure of a user and the information of the distance between the pressed area of the handwriting pen and the pen end of the handwriting pen are detected when the user signs on the touch panel through the handwriting pen.

12. The method of claim 10 or 11, wherein the sampling time and sampling frequency of the first signature data and the second signature data are kept synchronized.

13. A terminal, characterized in that the terminal comprises: the touch panel, the display panel, the sensor, the processor, the memory and the communication unit;

the touch panel is used for receiving a signature input by a user through a handwriting pen;

the display panel is used for displaying the image of the signature;

the touch panel is also used for detecting coordinate information of a contact point of the stylus pen and the touch panel;

the sensor is used for detecting pressure information of the stylus pen on the touch panel at the contact point; the coordinate information of the contact point and the pressure information of the stylus pen on the touch panel at the contact point form first signature data;

the communication unit is used for establishing communication connection with the stylus pen and receiving second signature data sent by the stylus pen, wherein the second signature data comprise motion track information of the stylus pen and pressure information of a user on the stylus pen, which are detected by the stylus pen when the user signs on the touch panel through the stylus pen;

the memory is used for storing a preset matching rate threshold value;

the signature corresponds to a first signature characteristic point and a second signature characteristic point, the first signature characteristic point comprises at least one point in a set formed by the contact points, and the second signature characteristic point comprises at least one point in a set of points of the handwriting pen in the motion track of the area outside the touch panel; the processor is used for extracting data corresponding to the first signature characteristic point and the second signature characteristic point from the first signature data and the second signature data; matching and comparing the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to obtain a matching rate; when the matching rate is not lower than the preset matching rate threshold, indicating the display panel to display prompt information that the signature authentication passes;

the display panel is also used for displaying prompt information that the signature authentication passes.

14. The terminal of claim 13, wherein the processor is further configured to send control information of a sampling time and a sampling frequency of the stylus to control the sampling time and the sampling frequency of the first signature data and the second signature data to be kept synchronized.

15. The terminal according to claim 13 or 14, wherein the processor is specifically configured to extract a first signature feature point from the contact points; projecting the motion track of the pen end of the stylus pen on a first plane where the touch panel is located to obtain a first motion track of the pen end of the stylus pen; projecting the motion trail of the pen end of the stylus pen on a second plane and a third plane which are perpendicular to the first plane to obtain a second motion trail and a third motion trail of the pen end of the stylus pen, wherein the second plane is perpendicular to the third plane; extracting a second signature characteristic point from at least one of the first motion track, the second motion track and the third motion track; extracting data corresponding to the first signature characteristic point and the second signature characteristic point from the first signature data and the second signature data; and matching and comparing the data corresponding to the first signature characteristic point and the second signature characteristic point with the data of each characteristic point in the signature template data to obtain a matching rate.

16. The terminal of claim 13, wherein the processor is further configured to determine an environment in which the terminal is located according to a network to which the communication unit is connected, and preset the matching rate threshold according to the environment in which the terminal is located.

17. A stylus, characterized in that the stylus comprises: the device comprises a sensor unit, a processor and a communication unit;

the sensor unit is used for detecting motion track information of a handwriting pen and pressure information of a user on the handwriting pen when the user signs a signature on a touch panel of a terminal through the handwriting pen;

the processor is used for converting the motion trail information of the handwriting pen and the pressure information of the user on the handwriting pen into second signature data which can be processed by the terminal, and indicating the communication unit to send the second signature data to the terminal;

the signature corresponds to a first signature characteristic point and a second signature characteristic point, the first signature characteristic point comprises at least one point in a set formed by contact points, the second signature characteristic point comprises at least one point in a set of points of the handwriting pen in the motion track of the area outside the touch panel, the communication unit is used for establishing communication connection with the terminal and sending the second signature data to the terminal, so that the terminal extracts data corresponding to the first signature characteristic point and the second signature characteristic point from the first signature data and the second signature data, the data corresponding to the first signature characteristic point and the second signature characteristic point is matched with the data of each characteristic point in the signature template data to determine whether the signature authentication passes or not, and the first signature data comprises coordinate information of the contact points of the handwriting pen and the touch panel and pressure of the handwriting pen on the touch panel at the contact points And (4) information.

18. The stylus pen according to claim 17, wherein the sensor unit is further configured to detect acceleration of the stylus pen, information of a pressed area and shape of the pressed area of the stylus pen that is pressed by a user, and information of a distance of the pressed area of the stylus pen from a pen tip of the stylus pen, when the user signs a signature on a touch panel of a terminal through the stylus pen.

19. The stylus pen of claim 17 or 18, wherein the communication unit is further configured to receive control information of a sampling time and a sampling frequency of the sensor unit transmitted by the terminal to control the sampling time and the sampling frequency of the first signature data and the second signature data to be kept synchronized.

20. A signature authentication system comprising the terminal of claim 13 and the stylus of claim 17.