Bioinformation Security Chip Based on Ion-Sensitive Field-Effect Transistor

Abstract

The present invention provides a bio-information security chip based on an ion-sensitive field-effect transistor, comprising: an ISFET array, a row and column word line selection circuit and a bit line selection circuit in the ISFET array respectively controlled by being connected to the ISFET array, a timing control circuit respectively connected to the word line selection circuit and the bit line selection circuit, and an input driving circuit connected to the word line selection circuit; a transimpedance amplifier and a physically unclonable function circuit are arranged at the output end of the bit line selection circuit, an analog-to-digital converter is arranged at the output end of the transimpedance amplifier, and an encryption circuit is arranged between the output end of the analog-to-digital converter and the output end of the physically unclonable function circuit. The present invention combines an ISFET array with PUF technology, utilizes the physical characteristics of the ISFET array to generate a unique and non-replicable key; according to the key, the encryption circuit is used to encrypt digital signals to obtain encrypted data, so as to protect bio-information from being stolen.

Description

Technical Field

[0001] The present invention relates to the field of biosensors, and particularly to a bioinformation security chip based on an ion-sensitive field-effect transistor. Background Art

[0002] Currently, the existing detection methods have the following problems:

[0003] 1. The detection efficiency and accuracy are insufficient. Traditional detection methods usually rely on a single sensor or channel for measurement, which not only limits the detection speed but also may lead to data incompleteness and low precision.

[0004] 2. There are many problems with the traditional idea of using traditional electronic circuits to generate keys. Since the method of generating keys by traditional electronic circuits is vulnerable to attacks; there are major problems in key distribution and management for symmetric cryptography algorithms; traditional key generation methods lack flexibility and scalability; there are problems in key generation rate and repetition rate; there are also deficiencies in implementation cost and complexity. In response to this, the present invention designs the security of a chip based on a high-precision key generation mechanism of pH value.

[0005] 3. Traditional electronic circuits face many problems when reading keys, including vulnerability to physical attacks, complexity of key management, insufficient security, resource limitations and adaptability problems, insufficient ability to resist side-channel attacks, and lack of signature functions, etc. These problems make traditional electronic circuits appear unreliable and insecure in the modern information security environment. Summary of the Invention

[0006] In view of the above situation, the main purpose of the present invention is to propose a bioinformation security chip based on an ion-sensitive field-effect transistor to solve the above technical problems.

[0007] The present invention proposes a bioinformation security chip based on an ion-sensitive field-effect transistor, including: an ISFET array, a word line selection circuit and a bit line selection circuit connected to the ISFET array for respectively controlling rows and columns in the ISFET array, a timing control circuit respectively connected to the word line selection circuit and the bit line selection circuit, and an input driving circuit connected to the word line selection circuit;

[0008] A transimpedance amplifier and a physically unclonable function circuit are provided at the output end of the bit line selection circuit. An analog-to-digital converter is provided at the output end of the transimpedance amplifier, and an encryption circuit is provided between the output end of the analog-to-digital converter and the output end of the physically unclonable function circuit.

[0009] During the operation of the present invention, the gate of the ISFET array is brought into contact with an external reference electrode through a sample solution. The threshold voltage is affected by the surface charge change of the pH value at the contact between the solution and the ISFET gate to output a current signal. A transimpedance amplifier converts the current signal output by the ISFET array into a voltage analog signal, and an analog-to-digital converter converts the voltage analog signal into a digital signal;

[0010] The physically unclonable function circuit receives the current signal output by the ISFET array and generates a unique and non-replicable identifier or key by utilizing the physical characteristics of the ISFET array;

[0011] According to the unique and non-replicable identifier or key, an encryption circuit is used to encrypt the digital signal to obtain the encrypted data, which is then output to an external device or system through an output interface circuit. Thus, while improving the accuracy and reliability of biological detection, the data security can be enhanced to protect biological information from being stolen.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] The present invention combines an ISFET array with PUF technology and can be used to generate secure keys. PUF technology utilizes the physical characteristics of hardware to generate unique and unpredictable keys. These physical characteristics, such as minor differences in the manufacturing process, make the response of each device unique and thus can be used as keys. The ISFET array has higher sensitivity, faster response speed, and better integration ability compared with traditional detection methods. The principle of generating PUF keys by the ISFET array is to convert the measured response values into binary data; the extracted binary data is used as the PUF key. Since the response of each ISFET is unique, the generated key is also unique. Therefore, the security of biological information can be better protected.

[0014] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of a biological information security chip based on an ion-sensitive field-effect transistor proposed by the present invention;

[0016] Figure 2 It is a structural diagram of the ISFET array of the present invention;

[0017] Figure 3 It is a structural diagram of the ISFET of the present invention;

[0018] Figure 4Structural diagram of the physical unclonable function circuit of the present invention;

[0019] Figure 5 Flow chart of the chip operation of the present invention.

[0020] In the figure, 01 is an ISFET; 02 is a transistor; 011 is a P-substrate; 012 is an n-well; 013 is a p+ implantation region; 014 is a first insulating layer; 015 is a conductive component; 016 is a second insulating layer; 017 is an ion-sensitive membrane; 03 is a capacitor. Detailed implementation manners

[0021] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0022] Referring to the following description and drawings, these and other aspects of the embodiments of the present invention will become clear. In these descriptions and drawings, some specific implementation manners in the embodiments of the present invention are specifically disclosed to represent some ways of implementing the principles of the embodiments of the present invention. However, it should be understood that the scope of the embodiments of the present invention is not limited thereto.

[0023] Please refer to Figure 1 , this embodiment provides a bioinformation security chip based on an ion-sensitive field-effect transistor, including: an ISFET (ion-sensitive field-effect transistor) array, a word line selection circuit and a bit line selection circuit connected to the ISFET array for respectively controlling the rows and columns in the ISFET array, a timing control circuit respectively connected to the word line selection circuit and the bit line selection circuit, and an input driving circuit connected to the word line selection circuit;

[0024] A transimpedance amplifier and a physical unclonable function circuit are provided at the output end of the bit line selection circuit. An analog-to-digital converter is provided at the output end of the transimpedance amplifier, and an encryption circuit is provided between the output end of the analog-to-digital converter and the output end of the physical unclonable function circuit.

[0025] Among them, the ISFET array is used to detect ion concentration or potential changes and output a current signal;

[0026] The word line selection circuit and the bit line selection circuit are connected to the ISFET array and are used to respectively control the rows and columns in the ISFET array;

[0027] The input driving circuit is connected to the word line selection circuit and is used to amplify and adjust the input signal;

[0028] A timing control circuit, which is respectively connected to a word line selection circuit and a bit line selection circuit, and is used to issue timing control instructions to the word line selection circuit and the bit line selection circuit;

[0029] A transimpedance amplifier, which is connected to the bit line selection circuit and is used to convert the current signal output by the ISFET array into a voltage signal;

[0030] A physically unclonable function circuit, which is connected to the bit line selection circuit, receives the current signal output by the ISFET array, and uses the physical characteristics of the ISFET array to generate a unique and non-replicable identifier or key;

[0031] An analog-to-digital converter, which is connected to the transimpedance amplifier and is used to convert the analog signal output by the transimpedance amplifier into a digital signal;

[0032] An encryption circuit, which is connected to the analog-to-digital converter and the physically unclonable function circuit, and is used to encrypt the digital signal according to the unique and non-replicable identifier or key to protect the security of the data;

[0033] An output interface circuit, which is used to output the encrypted data to an external device or system.

[0034] During the working process of the present invention, the gate of the ISFET array is contacted with an external reference electrode through a sample solution; the input signal is transmitted to the inside of the chip through the input driving circuit; the word line selection circuit and the bit line selection circuit select specific ISFETs for operation according to the instructions of the timing control circuit; the threshold voltage is affected by the surface charge change of the pH value of the solution in contact with the gate of the ISFET to output a current signal, and the signal is output to the transimpedance amplifier, which converts the current signal output by the ISFET array into a voltage analog signal, and the voltage analog signal is converted into a digital signal through the analog-to-digital converter;

[0035] The physically unclonable function circuit receives the current signal output by the ISFET array and uses the physical characteristics of the ISFET array to generate a unique and non-replicable identifier or key;

[0036] According to the unique and non-replicable identifier or key, the digital signal is encrypted by the encryption circuit to obtain the encrypted data, and the encrypted data is output to an external device or system through the output interface circuit to complete the biological information detection and encrypted transmission.

[0037] Further, a calibration circuit is further included. The calibration circuit is respectively connected to the timing control circuit and the analog-to-digital converter, and is used to correct the output of the ISFET array according to the timing control instruction to eliminate system errors and improve measurement accuracy.

[0038] Please refer to Figure 2, as a further preferred embodiment of the present invention, the ISFET array includes a plurality of ISFET01, and a transistor 02 is provided on each ISFET. The drain of the transistor is connected to the source of the ISFET, and the gate and source of the transistor are respectively connected to a word line and a bit line. By Figure 2 It can be seen that the main components of the ISFET array of the present invention include: ISFET: represented by a dotted line box. A transistor is provided on each ISFET. In this embodiment, the transistor is an NMOS transistor. The drain of the transistor is connected to the source of the ISFET, and the gate and drain of the transistor are respectively connected to a word line (word line) and a bit line (bit line). Bit Lines: Word Lines: The horizontal lines in the figure represent word lines for selecting a specific ISFET, and the vertical lines in the figure represent bit lines for reading and writing data. Among them, the bit lines are marked as BL 1, BL 2,..., BL n-1, BL n, representing different columns. The word lines are marked as WL 1, WL 2,..., WL n-1, WL n, representing different rows. When the word line is activated, the corresponding ISFET is selected, and data can be read or written through the bit line.

[0039] Please refer to Figure 3 , as a further preferred embodiment of the present invention, the ISFET includes a P-substrate 001, an n-trap 012 is embedded in the upper part of the P-substrate, and two p+ implantation regions 013 are embedded in the upper part of the n-trap. A first insulating layer 014 is covered on the upper part of the n-trap. The two sides of the first insulating layer extend outward and respectively cover the upper parts of the two p+ implantation regions. A source electrode and a drain electrode are respectively provided on the two p+ implantation regions. A conductive component 015 is provided on the first insulating layer, and a second insulating layer 016 and an ion-sensitive film 017 are sequentially covered on the conductive component.

[0040] It should be noted that the conductive component can be made of a metal material commonly used in ISFETs.

[0041] Ordinary ISFET structures may not be sensitive enough to ion-induced changes in electrical signals. In contrast, the present invention uses a P-substrate as a basis to provide a stable semiconductor environment. The combined action of two p+ implantation regions and n-traps forms a special electric field distribution and carrier transport channel. When ions generated by a chemical substance approach, this structure can more effectively change the carrier concentration and distribution, thereby generating a more obvious change in the electrical signal. Compared with ordinary structures, it has a higher sensitivity to changes in ion concentration, can capture weaker signals, and exhibits higher sensitivity when detecting chemical substances. The traditional ISFET structure has limited control over carriers and the electric field strength in the ion-sensitive region. The two p+ implantation regions of the present invention are completely embedded in the n-traps, which is equivalent to constructing a more enclosed and precisely controllable carrier environment. This not only enhances the electric field strength in the ion-sensitive region, making the interaction between ions and the semiconductor surface stronger, but also precisely limits the movement path and range of carriers. This makes the structure more selective for specific chemical substances, can more accurately identify target chemical substances. At the same time, it can more precisely convert changes in chemical substance concentration into electrical signals, achieve high-precision measurement, effectively avoid interference from other non-target substances, and improve the reliability of detection results. From the perspective of the improved part, by introducing a special P-substrate, p+ implantation regions, and n-trap structures, the signal capture and conversion mechanism is essentially changed. This structural innovation combines electrochemistry and semiconductor technology, making use of the sensitive characteristics of semiconductor materials to changes in electrical signals and achieving targeted recognition through electrochemical processes. When detecting chemical substances, the sensitivity and selectivity far exceed those of traditional structures. In terms of performance, the precise structural design ensures precise signal conversion, can measure the concentration of chemical substances with high precision, and the optimized internal structure and material selection enable it to operate stably in complex environments, resist interference, and ensure reliable and consistent results, showing obvious advantages compared with traditional structures.

[0042] Physical unclonable function circuits exhibit great potential and advantages in the fields of modern information security and hardware authentication due to their unique security features, high reliability, and multi-functional integration capabilities. To better protect the security of biological information, the present invention combines an ISFET array with PUF technology, which can be used to generate secure keys. PUF technology utilizes the physical characteristics of hardware to generate unique and unpredictable keys. These physical characteristics, such as minor differences in the manufacturing process, make the response of each device unique, which can thus be used as a key. The principle of the ISFET array generating PUF keys is to convert the measured response values into binary data; the extracted binary data is used as the PUF key. Since the response of each ISFET is unique, the generated key is also unique.

[0043] The structure of the physical unclonable function circuit is shown in Figure, please refer to Figure 4As shown in the figure, it includes a multiplexer and a comparator. The multiplexer is connected to the comparator. The multiplexer is connected to all bit lines, and a capacitor 03 is provided at the output end of each bit line. The multiplexer selects two of the bit line signals and transmits them to the comparator for comparison. By comparing the voltages of any two bit lines, a physically unclonable output is obtained, and a bit configuration control word is obtained.

[0044] Its working principle is as follows: Any row of the ISFET array is selected through the word line, and the bit line voltage is transmitted into the multiplexer. The multiplexer selects two of the bit line signals and transmits them to the comparator for comparison. Due to the manufacturing deviation of the ISFET process, the leakage currents generated by different ISFETs are different when no detection is performed, and the charging rates of the capacitors are also different. Therefore, a physically unclonable output can be obtained by comparing the voltages of any two bit lines.

[0045] In addition, in order to improve reliability and ensure that the output of the physically unclonable function can obtain a stable output under different ambient voltage and temperature conditions, a threshold discrimination module and a bit configuration memory are designed;

[0046] Among them, the threshold discrimination module is respectively connected to the multiplexer and the comparator, and the stable bit is selected as the output by comparing the voltage difference between the two input ends of the comparator with the threshold voltage, and a stable bit configuration control word is obtained.

[0047] Among them, the bit configuration memory is connected to the comparator and is used to store all stable bit configuration control words as the encryption key.

[0048] In the chip registration stage, the voltage difference between the two input ends of the comparator is compared with the threshold voltage. When the voltage difference between the two ends of the comparator is less than the threshold, the output of this response is defined as an unstable bit, and this bit will be directly discarded. After the traversal is completed, finally all stable bit configuration control words are stored in the bit configuration memory; in the chip authentication stage, the bit configuration control word is loaded, and then the response of the physically unclonable function is serially read out as the encryption key.

[0049] In order to elaborate the present invention in more detail, the basic principle of encryption and the chip working process are disclosed as follows:

[0050] 1) Basic principle of encryption

[0051] Encryption process: Assume that the original digital signal is X and the encryption key is W. The encrypted signal can be simply expressed as:

[0052] Y = X ⊕ W;

[0053] Among them, ⊕ represents the exclusive OR operation.

[0054] Transmission process: Transmit the encrypted signal Y outside the chip. Since W has been read and stored on the server side during the chip internal stage.

[0055] Decryption process: The decryption process can be expressed as:

[0056] Y′ = Y ⊕ W;

[0057] where Y′ is the decrypted signal.

[0058] Actual circuit implementation: In actual circuit implementation, more complex encryption algorithms such as AES (Advanced Encryption Standard) etc. can be adopted.

[0059] 2) Chip working mode

[0060] The chip working flow chart is as Figure 5 shown, and its process is:

[0061] 1. Chip key registration: Read the biometric on the chip: Use a sensor to read the biometric information on the chip. Store the biometric on the server: Store the read biometric information on the server for subsequent use.

[0062] 2. Biologic detection phase:

[0063] Drop the liquid on the chip: Drop the liquid containing the biometric on the chip. Utilize the sensitivity of the chip to change the signal: The chip has a sensitive reaction to the biometric in the liquid, resulting in a signal change. Design a circuit to convert the analog signal to a digital signal: Convert the changing analog signal to a digital signal through circuit design. And store it on the server: Store the converted digital signal on the server.

[0064] 3. Encrypted biometric data transmission:

[0065] Transmit the encrypted data outside the chip.

[0066] 4. Device authentication and biometric decryption

[0067] Use devices such as FPGA for decryption: Use devices such as Field Programmable Gate Array (FPGA) to decrypt the encrypted data. Only by knowing the correct biometric ID can the data be successfully decrypted.

[0068] It should be understood that although the steps in the flowcharts of the embodiments of the present invention are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in each embodiment may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0069] It should be understood that various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following technologies well known in the art can be used: discrete logic circuits with logic gate circuits for implementing logic functions on data signals, application specific integrated circuits with appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0070] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0071] The above-described embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A bio-information security chip based on an ion-sensitive field effect transistor, characterized in that Comprising: An ISFET array, a word line selection circuit and a bit line selection circuit that are connected to the ISFET array and used to control the rows and columns in the ISFET array respectively, a timing control circuit that is respectively connected to the word line selection circuit and the bit line selection circuit, and an input driving circuit that is connected to the word line selection circuit; A transimpedance amplifier and a physically unclonable function circuit are provided at the output end of the bit line selection circuit, an analog-to-digital converter is provided at the output end of the transimpedance amplifier, and an encryption circuit is provided between the output end of the analog-to-digital converter and the output end of the physically unclonable function circuit; The gate of the ISFET array is in contact with an external reference electrode through a sample solution; The input signal is transmitted into the chip through the input driving circuit; The word line selection circuit and the bit line selection circuit select specific ISFETs for operation according to the instructions of the timing control circuit; the threshold voltage is affected by the surface charge change of the pH value of the solution in contact with the ISFET gate to output a current signal, and the signal is output to the transimpedance amplifier. The transimpedance amplifier converts the current signal output by the ISFET array into a voltage analog signal, and the analog-to-digital converter converts the voltage analog signal into a digital signal; The physically unclonable function circuit receives the current signal output by the ISFET array and generates a unique and non-replicable identifier or key by using the physical characteristics of the ISFET array; According to the unique and non-replicable identifier or key, the encryption circuit encrypts the digital signal to obtain the encrypted data, and outputs it to an external device or system through the output interface circuit to complete the biological information detection and encrypted transmission.

2. The bio-information security chip based on an ion-sensitive field effect transistor according to claim 1, wherein It further includes a calibration circuit, and the calibration circuit is respectively connected to the timing control circuit and the analog-to-digital converter.

3. The bio-information security chip based on an ion-sensitive field effect transistor according to claim 2, characterized in that, The ISFET array includes a plurality of ISFETs, and a transistor is provided on each ISFET. The drain of the transistor is connected to the source of the ISFET, and the gate and source of the transistor are respectively connected to a word line and a bit line.

4. The bio-information security chip based on an ion-sensitive field effect transistor according to claim 3, characterized in that, The ISFET includes a P-substrate, an n-well is embedded in the upper part of the P-substrate, and two p+ implantation regions are embedded in the upper part of the n-well. The upper part of the n-well is covered with a first insulating layer, and both sides of the first insulating layer extend outward to cover the upper parts of the two p+ implantation regions respectively. Source electrodes and drain electrodes are respectively provided on the two p+ implantation regions, a conductive component is provided on the gate oxide region, and a second insulating layer and an ion-sensitive film are sequentially covered on the conductive component.

5. The bio-information security chip based on an ion-sensitive field effect transistor according to claim 4, characterized in that, The physically unclonable function circuit includes a multiplexer and a comparator. The multiplexer is connected to the comparator. The multiplexer is connected to all bit lines, and a capacitor is provided at the output end of each bit line. The multiplexer selects two bit line signals and transmits them to the comparator for comparison, and obtains a physically unclonable output by comparing the voltages of any two bit lines to obtain a bit configuration control word.

6. The bio-information security chip based on an ion-sensitive field effect transistor according to claim 5, characterized in that The physically unclonable function circuit further includes a threshold discrimination module. The threshold discrimination module is respectively connected to the multiplexer and the comparator, and selects a stable bit as the output by comparing the magnitude of the voltage difference between the two input ends of the comparator with the threshold voltage to obtain a stable bit configuration control word.

7. The bio-information security chip based on an ion-sensitive field effect transistor according to claim 6, characterized in that, The physically unclonable function circuit further includes a bit configuration memory, and the bit configuration memory is connected to a comparator for storing all stable bit configuration control words as keys for encryption.

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