Imaging apparatus and method of processing image signal

Abstract

The invention relates to an imaging apparatus and a method of processing an image signal. An imaging apparatus may include: a physical unclonable function (PUF) pixel selection unit configured to select a second pixel having the same color as a first pixel designated to generate PUF data; a noise extraction unit configured to extract a first noise value of the first pixel and extract a second noise value of the second pixel; and a PUF data generation unit configured to generate PUF data based on the first noise value and the second noise value.

Description

Technical Field

[0001] Various embodiments relate to an imaging device having an encryption function of image data. Background Art

[0002] An imaging device is a device that captures optical images using the properties of photodetecting semiconductor materials that react to light. With the development of industries such as vehicles, medical, computers, and communications, the demand for high-performance imaging devices has increased in various fields such as smartphones, digital cameras, gaming devices, the Internet of Things, robots, security cameras, and medical miniature cameras.

[0003] Imaging devices can be basically divided into charge coupled device (CCD) imaging devices and complementary metal oxide semiconductor (CMOS) imaging devices. CCD imaging devices provide better image quality than CMOS imaging devices, but tend to consume more power than CMOS imaging devices because CCD imaging devices are implemented to have a larger size than CMOS imaging devices. In contrast, CMOS imaging devices can be specifically implemented to have a smaller size than CCD imaging devices and consume less power than CCD imaging devices. In addition, CMOS imaging devices can integrate light detection elements and signal processing circuits into a single chip because CMOS imaging devices are manufactured using CMOS manufacturing technology. Therefore, small CMOS imaging devices can be produced at low cost. Therefore, CMOS imaging devices are developed for many applications including mobile devices. Summary of the invention

[0004] Various embodiments are directed to providing an imaging device with an encryption function that has high stability against hacker attacks on image data.

[0005] The technical problems of the present disclosure are not limited to the above-mentioned technical problems, and those skilled in the art will clearly understand other technical problems not mentioned herein from the following description.

[0006] In an embodiment, an imaging device may include: a physical unclonable function (PUF) pixel selection unit configured to select a second pixel having the same color as a first pixel designated to generate PUF data; a noise extraction unit configured to extract a first noise value of the first pixel and extract a second noise value of the second pixel; and a PUF data generation unit configured to generate PUF data based on the first noise value and the second noise value.

[0007] In an embodiment, a method for processing an image signal may include the following steps: selecting a first pixel based on challenge data specifying the position of at least one pixel of a pixel array; selecting a second pixel having the same color as the first pixel; extracting a noise value of each of the first pixel and the second pixel; and generating response data by comparing the noise value of the first pixel and the noise value of the second pixel.

[0008] According to the embodiments disclosed in this document, by encrypting image data using information randomly generated in association with unique characteristics in addition to fixed information attributed to unique characteristics within an imaging device, malicious fraud and unauthorized interpretation by others can be prevented.

[0009] In addition, various effects directly or indirectly understood through this document can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a block diagram briefly illustrating an imaging device according to an embodiment of the present disclosure.

[0011] Figure 2 is a flowchart for describing the operation of the imaging device according to the embodiment of the present disclosure.

[0012] Figure 3 Is used to describe Figure 1 FIG. 2 is a diagram of the operation of a PUF data generation unit according to an embodiment.

[0013] Figures 4 to 6 is a diagram for describing an operation of a PUF data generation unit according to an embodiment in a pixel array having a plurality of patterns.

[0014] Figure 7 is a diagram for describing the shift of noise values ​​corresponding to color filters. DETAILED DESCRIPTION

[0015] Hereinafter, various embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be noted that the present disclosure is not limited to a specific embodiment, but includes various modifications, equivalents and / or substitutions. The embodiments of the present disclosure may provide various effects that can be directly and indirectly recognized by the present disclosure.

[0016] Figure 1 is a block diagram briefly illustrating an imaging device according to an embodiment of the present disclosure.

[0017] Reference Figure 1, the imaging device 10 may be a device capable of communicating with a host device 20 which is an external device located outside the imaging device 10. The imaging device 10 may include an image sensing device 100, a physical unclonable function (PUF) data generation unit 200, a PUF pixel selection unit 210, a noise extraction unit 220, and a response data output unit 230.

[0018] The imaging device 10 may include a pixel array of imaging pixels that converts light into pixel signals to generate image data (IDADA) by capturing a scene. The pixel array may include pixel color filters that are respectively located at the imaging pixels to filter the incident light to be received by the imaging pixels to capture the color information of the captured scene. The image capture operation of the imaging device 10 may be triggered or executed in response to a request from the host device 20 or according to a predetermined rule (e.g., a time cycle or condition). In an example, the imaging device 10 may receive challenge data CDATA from the host device 20, generate response data RDATA corresponding to the received challenge data CDATA by using a physical unclonable function (PUF), and output the response data RDATA to the outside, the PUF generating the response data RDATA based on unique characteristics within the imaging device 10 due to subtle differences in the semiconductor process for manufacturing the imaging device 10.

[0019] In an implementation, the PUF may output a response to a challenge by using a unique characteristic within the imaging device 10. For example, the PUF compares the output response with previously stored comparison response data, determines whether the output response is the same as the comparison response data, and authenticates the imaging device based on the determination. In the examples disclosed in this document, the challenge data CDATA corresponds to a challenge provided to the PUF, and the response data RDATA corresponds to a response provided from the PUF.

[0020] The unique characteristics within the imaging device 10 used in the PUF may include fixed pattern noise (FPN) and random telegraph noise (RTN). For example, the PUF data may include information corresponding to at least one FPN and at least one RTN. In an example, the PUF data may also include information corresponding to a threshold voltage value attributable to the unique characteristics of a transistor of one pixel. In an example, the PUF data and the response data RDATA may refer to the same data.

[0021] The image sensing device 100 may generate image data IDATA by capturing a scene. The generated image data IDATA may include a pixel noise value unique to the pixel. For example, the unique noise value of the pixel may include an FPN attributed to a unique characteristic within the imaging device 10 and an RTN randomly generated in association with the unique characteristic within the imaging device 10. In an example, the unique noise value of the pixel may include a threshold voltage value of at least one transistor corresponding to the pixel. The threshold voltage value refers to a voltage that turns on or off the corresponding transistor of the pixel. For example, the noise value of the pixel may include an FPN, an RTN, and a threshold voltage value based on the characteristics within the imaging device 10.

[0022] The image sensing device 100 may output image data IDATA including a pixel noise value including at least one of FPN, RTN, or a threshold voltage value, which is associated with the characteristics of the imaging device 10 and is unique to the pixel. In an example, the image sensing device 100 may output image data IDATA including at least one of FPN, RTN, or a threshold voltage value of at least one transistor within the pixel corresponding to the characteristics of the pixel.

[0023] In an example, FPN may be obtained due to leakage current generated in a pixel under a condition where light is not transmitted to the pixel array (i.e., a dark condition). In an example, RTN may be or may include noise occurring in a drive transistor DX of a pixel, and may be randomly generated or may be obtained from noise occurring in a drive transistor DX of a pixel that senses incident light.

[0024] The PUF data generation unit 200 may include a PUF pixel selection unit 210 , a noise extraction unit 220 , and a response data output unit 230 .

[0025] The PUF data generation unit 200 may generate PUF data by receiving the image data IDATA and the challenge data CDATA. In an implementation, the PUF data is generated by the PUF data generation unit 200, and the generated PUF data is output as the response data RDATA.

[0026] The PUF pixel selection unit 210 may select pixels for generating PUF data based on the challenge data CDATA.

[0027] In an example, the challenge data CDATA may include information specifying the position of a pixel. For example, the challenge data CDATA may include information indicating the position of a first column and a first row of a pixel array included in the imaging device 10. In this case, the PUF pixel selection unit 210 may identify a first pixel disposed at the first column and the first row and select a second pixel corresponding to the first pixel.

[0028] In an example, when a first pixel is designated by receiving challenge data CDATA, the PUF pixel selection unit 210 may select a second pixel including a color filter having the same color as that of the first pixel. The PUF pixel selection unit 210 may send pixel data of the first pixel and pixel data of the second pixel to the noise extraction unit 220.

[0029] The noise extraction unit 220 may extract noise of each pixel by receiving the pixel data from the PUF pixel selection unit 210 .

[0030] In an example, the noise extraction unit 220 may extract at least one of FPN, RTN, or a threshold voltage value of a transistor corresponding to a pixel from the pixel data received from the PUF pixel selection unit 210. For example, the noise extraction unit 220 may extract noise data of a first pixel and noise data of a second pixel from the pixel data received from the PUF pixel selection unit 210. In an example, the noise data of the first pixel and the noise data of the second pixel may include at least one of FPN or RTN corresponding to the characteristics of the pixel. In an example, the noise data may include a threshold voltage value of at least one transistor corresponding to a pixel designated or selected by the PUF pixel selection unit 210.

[0031] The response data output unit 230 may generate PUF data based on the noise data extracted from the noise data NDATA, and may output the generated PUF data to the response data RDATA.

[0032] In an example, the response data output unit 230 may determine each bit of the PUF data by comparing the noise data of the first pixel and the noise data of the second pixel. In an example, the response data output unit 230 may determine the level of the first bit of the PUF data as a first logic level or a second logic level based on the comparison result between the noise data of the first pixel and the noise data of the second pixel selected according to the first pixel. When each bit of the PUF data is determined, the response data output unit 230 may output the determined bit as the response data RDATA.

[0033] In an implementation, the PUF data generation unit 200 may receive challenge data CDATA, may select pixels for generating PUF data by using the PUF pixel selection unit 210, may extract noise values ​​of the selected pixels by using the noise extraction unit 220, may generate PUF data based on the extracted noise values ​​by using the response data output unit 230, and may output the generated PUF data as response data RDATA.

[0034] The detailed operation of the PUF data generating unit 200 will be referred to later. Figure 3 describe.

[0035] Figure 2 is a flowchart for describing the operation of the imaging device according to the embodiment of the present disclosure.

[0036] Reference Figure 2 According to the embodiment, the operation of the PUF data generation unit 200 may include: step S100, selecting a first pixel based on the challenge data CDATA; step S110, selecting a second pixel with the same color as the first pixel; step S120, extracting a first noise value from the first pixel and extracting a second noise value from the second pixel; step S130, comparing the first noise value and the second noise value; step S140, generating PUF data based on the comparison result; and step S150, outputting the generated PUF data as response data RDATA.

[0037] The input of challenge data CDATA may correspond to a challenge input for outputting a response in a common PUF operation.

[0038] In an example, the PUF pixel selection unit 210 may select a first pixel based on a pixel address specified by the challenge data CDATA (S100). For example, the challenge data CDATA may include data indicating a first row and a first column of a pixel array. In this case, the PUF pixel selection unit 210 may identify the first pixel in response to the challenge data CDATA.

[0039] In an example, the challenge data CDATA may include data indicating pixels disposed in a first row of the pixel array. In this case, the PUF pixel selection unit 210 may identify pixels disposed in the first row of the pixel array in response to the challenge data CDATA.

[0040] In an example, the PUF pixel selection unit 210 may select a second pixel having the same color as the first pixel selected in step S100 (S110). For example, if the first pixel includes a red (R) filter, the PUF pixel selection unit 210 may select a second pixel including an R filter.

[0041] although Figure 2It is shown that the first pixel and the second pixel are selected in S100 and S110, but the number of pixels selected by the PUF pixel selection unit 210 is not limited to two and may vary. In the example, the PUF pixel selection unit 210 may select a plurality of first pixels at S100 and a plurality of second pixels corresponding to the plurality of first pixels at S110. The PUF pixel selection unit 210 may select a plurality of pixels having the same colors as the plurality of pixels selected in step S100. For example, if a first pixel including an R filter and a second pixel including a green (G) filter are specified in step S100, the PUF pixel selection unit 210 may select a third pixel including an R filter and corresponding to the first pixel and a fourth pixel including a G filter and corresponding to the second pixel. In the description, in this case, the distance between the first pixel and the third pixel may be the same as the distance between the second pixel and the fourth pixel.

[0042] In an example, the noise extraction unit 220 may extract a first noise value from a first pixel and a second noise value from a second pixel selected in step S110 (S120). For example, the noise extraction unit 220 may extract at least one of RTN, FPN, or a noise value including at least one threshold voltage value of a transistor corresponding to the first pixel from pixel data of a first pixel included in the image data IDATA. In addition, the noise extraction unit 220 may extract at least one of RTN, FPN, or a noise value including at least one threshold voltage value of a transistor corresponding to the second pixel from pixel data of a second pixel included in the image data IDATA.

[0043] In an example, the noise extraction unit 220 may extract a first noise value from the first pixel and a second noise value from the second pixel selected in step S110, respectively. In an example, when a plurality of pixels are selected in each of steps S110 and S120, the noise extraction unit further extracts noise values ​​corresponding to the additional pixels. For example, if a third pixel is selected in S100 and a fourth pixel corresponding to the third pixel is selected in S110, the noise extraction unit 220 may extract a third noise value from the third pixel and a fourth noise value from the fourth pixel.

[0044] For example, the noise extraction unit 220 may extract at least one of RTN, FPN, or a noise value including a threshold voltage value of a transistor corresponding to the first pixel from the pixel data of the first pixel included in the image data IDATA. In an example, the noise extraction unit 220 may extract at least one of RTN, FPN, or a noise value including a threshold voltage value of a transistor corresponding to the second pixel from the pixel data of the second pixel included in the image data IDATA. In an example, the noise extraction unit 220 may extract at least one of RTN, FPN, or a noise value including a threshold voltage value of a transistor corresponding to the third pixel from the pixel data of the third pixel included in the image data IDATA. In an example, the noise extraction unit 220 may extract at least one of RTN, FPN, or a noise value including a threshold voltage value of a transistor corresponding to the fourth pixel from the pixel data of the fourth pixel included in the image data IDATA.

[0045] In an example, the response data output unit 230 may compare the first noise value and the second noise value extracted in step S120 (S130). For example, the response data output unit 230 may determine the magnitude relationship between the first noise value and the second noise value. For example, the response data output unit 230 may compare the sum of the values ​​of RTN and FPN among the noise values ​​of the first pixel and the sum of the values ​​of RTN and FPN among the noise values ​​of the second pixel.

[0046] In an example, the response data output unit 230 may compare the first noise value and the second noise value extracted in step S120, and may compare the third noise value and the fourth noise value extracted in step S120. For example, the response data output unit 230 may determine the magnitude relationship between the first noise value and the second noise value, and may determine the magnitude relationship between the third noise value and the fourth noise value. For example, the response data output unit 230 may compare the sum of the values ​​of RTN and FPN among the noise values ​​of the first pixel and the sum of the values ​​of RTN and FPN among the noise values ​​of the second pixel, and may compare the sum of the values ​​of RTN and FPN among the noise values ​​of the third pixel and the sum of the values ​​of RTN and FPN among the noise values ​​of the fourth pixel.

[0047] In an example, the response data output unit 230 may generate PUF data based on the comparison result in step S130 (S140). The generated PUF data may correspond to the response data RDATA. For example, the response data output unit 230 may generate PUF data and output the generated PUF data as the response data RDATA.

[0048] In an example, the response data output unit 230 may determine the first bit of the PUF data by comparing the first noise value and the second noise value. For example, when the first noise value is greater than or equal to the second noise value, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the first noise value is less than the second noise value, the response data output unit 230 may determine the first bit of the PUF data as 0.

[0049] In an example, the response data output unit 230 may determine the first bit of the PUF data by comparing the first noise value and the second noise value, and may determine the second bit of the PUF data by comparing the third noise value and the fourth noise value. For example, when the first noise value is greater than or equal to the second noise value, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the first noise value is less than the second noise value, the response data output unit 230 may determine the first bit of the PUF data as 0. In an example, when the third noise value is greater than or equal to the fourth noise value, the response data output unit 230 may determine the second bit of the PUF data as 1, and when the third noise value is less than the fourth noise value, the response data output unit 230 may determine the second bit of the PUF data as 0.

[0050] In an example, the response data output unit 230 may output the PUF data generated in step S140 as the response data RDATA (S150). In this case, the output response data RDATA may be transmitted to the host device 20. For example, when the first bit of the PUF data is determined to be 0, the response data output unit 230 may output the response data RDATA whose first bit is 0. For example, when the first bit and the second bit of the PUF data are determined to be 1 and 0, respectively, the response data output unit 230 may output the response data RDATA whose first bit and the second bit are 1 and 0, respectively.

[0051] Figure 3 Is used to describe Figure 1 FIG. 2 is a diagram of the operation of a PUF data generation unit according to an embodiment.

[0052] Reference Figure 3 , the imaging device 10 may receive the challenge data CDATA and output the response data RDATA based on the PUF of the imaging device 10 .

[0053] In an example, the challenge data CDATA may include information identifying the position of a pixel included in the imaging device 10. For example, the challenge data CDATA may include information specifying the first row and the first column of the pixel array 300. In this case, the first pixel Pixel1 set in the first row and the first column may be specified according to the challenge data CDATA. When the first pixel Pixel1 is specified, the PUF pixel selection unit 210 may select a third pixel Pixel3 including a color filter having the same color as that of the first pixel Pixel1. For example, the first pixel Pixel1 and the third pixel Pixel3 may correspond to an R filter. The noise extraction unit 220 may extract noise data of the first pixel Pixel1 and noise data of the third pixel Pixel3. The response data output unit 230 may generate individual bits of PUF data by comparing the noise data of the first pixel Pixel1 and the noise data of the third pixel Pixel3, and may output the generated PUF data as the response data RDATA.

[0054] For example, when the noise data of the first pixel Pixel1 is greater than or equal to the noise data of the third pixel Pixel3, the response data output unit 230 may output the first bit of the response data RDATA as 1; when the noise data of the first pixel Pixel1 is less than the noise data of the third pixel Pixel3, the response data output unit 230 may output the first bit of the response data RDATA as 0.

[0055] In an example, the challenge data CDATA may include information specifying a plurality of pixels, such as the first row and the first column and the first row and the second column of the pixel array 300. In this case, the first pixel Pixel1 set in the first row and the first column of the pixel array 300 may be specified according to the information indicating the first row and the first column. The second pixel Pixel2 set in the first row and the second column of the pixel array 300 may be specified according to the information indicating the first row and the second column. When the first pixel Pixel1 and the second pixel Pixel2 are specified, the PUF pixel selection unit 210 may select a third pixel Pixel3 including a color filter having the same color as the color filter of the first pixel Pixel1 and a fourth pixel Pixel4 including a color filter having the same color as the color filter of the second pixel Pixel2. For example, the first pixel Pixel1 and the third pixel Pixel3 may correspond to an R color filter, and the second pixel Pixel2 and the fourth pixel Pixel4 may correspond to a green (G) color filter. The noise extraction unit 220 may extract noise data of the first pixel Pixel1 and noise data of the third pixel Pixel3, and may extract noise data of the second pixel Pixel2 and noise data of the fourth pixel Pixel4. The response data output unit 230 may determine each bit of PUF data by comparing the noise data of the first pixel Pixel1 and the third pixel Pixel3 and comparing the noise data of the second pixel Pixel2 and the fourth pixel Pixel4, and may output the PUF data determined by each bit as the response data RDATA.

[0056] For example, when the noise data of the first pixel Pixel1 is greater than or equal to the noise data of the third pixel Pixel3, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the noise data of the first pixel Pixel1 is less than the noise data of the third pixel Pixel3, the response data output unit 230 may determine the first bit of the PUF data as 0. When the noise data of the second pixel Pixel2 is greater than or equal to the noise data of the fourth pixel Pixel4, the response data output unit 230 may determine the second bit of the PUF data as 1, and when the noise data of the second pixel Pixel2 is less than the noise data of the fourth pixel Pixel4, the response data output unit 230 may determine the second bit of the PUF data as 0. The response data output unit 230 may output the PUF data determined by each bit as the response data RDATA.

[0057] Figures 4 to 6 is a diagram for describing an operation of a PUF data generation unit according to an embodiment in a pixel array having a plurality of patterns.

[0058] Reference Figure 4, the imaging device 10 may generate PUF data in a pixel array 400 including a Bayer pattern. The pixel array 400 includes red, green, and blue filters arranged in a specific repeating pattern (e.g., RGGB). In a pixel array having a Bayer pattern, the green filter is twice as many as the red filter and the blue filter. In an example, the PUF data generation unit 200 may output response data RDATA by receiving image data IDATA and challenge data CDATA. In this case, the challenge data CDATA may include information specifying the position of at least one pixel included in the pixel array 400 including the Bayer pattern. The PUF data generation unit 200 may select a pixel specified based on the challenge data CDATA and a pixel corresponding to the specified pixel through the PUF pixel selection unit 210, extract noise values ​​of the specified pixel and the selected pixel through the noise extraction unit 220, and generate PUF data by comparing the extracted noise value through the response data output unit 230 and output the generated PUF data as the response data RDATA.

[0059] For example, the challenge data CDATA may include information specifying the first row and the first column of the pixel array 400 including the Bayer pattern. In this case, the pixel R00 set in the first row and the first column may be specified based on the challenge data CDATA. When the pixel R00 is specified, the PUF pixel selection unit 210 may select the pixel R02 including the color filter of the same color as the color filter of the pixel R00. The noise extraction unit 220 may extract the noise data of the pixel R00 and the noise data of the pixel R02. The response data output unit 230 may generate each bit of the PUF data by comparing the noise data of the pixel R00 and the noise data of the pixel R02. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R02, the response data output unit 230 may determine the first bit of the PUF data to be 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R02, the response data output unit 230 may determine the first bit of the PUF data to be 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0060] For example, the challenge data CDATA may include information specifying the first row and the first column and the first row and the second column of the pixel array 400 including the Bayer pattern. In this case, according to the challenge data CDATA, the pixel R00 set in the first row and the first column may be specified and the pixel G01 set in the first row and the second column may be specified. When the pixel R00 and the pixel G01 are specified, the PUF pixel selection unit 210 may select the pixel R04 including the color filter of the same color as the color filter of the pixel R00 and the pixel G05 including the color filter of the same color as the color filter of the pixel G01. The noise extraction unit 220 may extract the noise data of the pixel R00 and the noise data of the pixel R04, and may extract the noise data of the pixel G01 and the noise data of the pixel G05. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R04, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R04, the response data output unit 230 may determine the first bit of the PUF data as 0. Likewise, when the noise data of the pixel G01 is greater than or equal to the noise data of the pixel G05, the response data output unit 230 may determine the second bit of the PUF data to be 1, and when the noise data of the pixel G01 is less than the noise data of the pixel G05, the response data output unit 230 may determine the second bit of the PUF data to be 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0061] Reference Figure 5 , the imaging device 10 can generate PUF data in a pixel array 410 including a quaternary pattern. The quaternary pattern groups red filters, green filters, and blue filters into a 2x2 matrix, and each pixel group includes a set of pixels having the same color filter and arranged in a 2x2 matrix. For example, the pixel array 410 includes a first pixel group 411 corresponding to a red filter, a second pixel group 412 corresponding to a green filter, a third pixel group 413 corresponding to a red filter, and a fourth pixel group 414 corresponding to a green filter, and the pixels of each pixel group are arranged in two columns and two rows.

[0062] In an example, the PUF data generation unit 200 may output response data RDATA by receiving image data IDATA and challenge data CDATA. In this case, the challenge data CDATA may include information specifying the position of at least one pixel included in the pixel array 410 including the quaternion pattern. The PUF data generation unit 200 may select a pixel specified based on the challenge data CDATA and a pixel corresponding to the specified pixel through the PUF pixel selection unit 210, extract noise values ​​of the specified pixel and the selected pixel through the noise extraction unit 220, and generate PUF data by comparing the extracted noise value through the response data output unit 230 and output the generated PUF data as the response data RDATA.

[0063] For example, the challenge data CDATA may include information specifying the first row and the first column of the pixel array 410 including the quaternion pattern. In this case, the pixel R00 set in the first row and the first column may be specified based on the challenge data CDATA. When the pixel R00 is specified, the PUF pixel selection unit 210 may select the pixel R01 including the color filter of the same color as the color filter of the pixel R00. The noise extraction unit 220 may extract the noise data of the pixel R00 and the noise data of the pixel R01. The response data output unit 230 may generate each bit of the PUF data by comparing the noise data of the pixel R00 and the noise data of the pixel R01. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R01, the response data output unit 230 may determine the first bit of the PUF data to be 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R01, the response data output unit 230 may determine the first bit of the PUF data to be 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0064] For example, the challenge data CDATA may include information specifying the first row and the first column and the first row and the third column of the pixel array 410 including the quaternion pattern. In this case, according to the challenge data CDATA, the pixel R00 set in the first row and the first column may be specified and the pixel G02 set in the first row and the third column may be specified. When the pixel R00 and the pixel G02 are specified, the PUF pixel selection unit 210 may select the pixel R01 including the color filter of the same color as the color filter of the pixel R00 and the pixel G03 including the color filter of the same color as the color filter of the pixel G02. The noise extraction unit 220 may extract the noise data of the pixel R00 and the noise data of the pixel R01, and may extract the noise data of the pixel G02 and the noise data of the pixel G03. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R01, the response data output unit 230 may determine the first bit of the PUF data to be 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R01, the response data output unit 230 may determine the first bit of the PUF data to be 0. Likewise, when the noise data of the pixel G02 is greater than or equal to the noise data of the pixel G03, the response data output unit 230 may determine the second bit of the PUF data to be 1, and when the noise data of the pixel G02 is less than the noise data of the pixel G03, the response data output unit 230 may determine the second bit of the PUF data to be 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0065] In an example, the pixel array 410 including the quaternary pattern may include a first pixel group 411 to a fourth pixel group 414. The pixel group may include a set of pixels having the same color filter among the pixels included in the pixel array 410 including the quaternary pattern, and the pixel set is arranged in a 2x2 matrix. Each pixel group may correspond to a unit group of the quaternary pattern. For example, the first pixel group 411 may include pixels R00, R01, R10, and R11 arranged in a 2x2 matrix and having an R color filter among the pixels included in the pixel array 410 including the quaternary pattern. For example, the second pixel group 412 may include pixels G02, G03, G12, and G13 arranged in a 2x2 matrix and having a G color filter among the pixels included in the pixel array 410 including the quaternary pattern.

[0066] The positions of the pixels included in each pixel group (e.g., 411 to 414) may be divided into the first channel to the fourth channel. For example, the position corresponding to the first row and the first column of the first pixel group 411 may be defined as the first channel of the first pixel group 411, and the pixel R00 may be defined as being disposed in the first channel of the first pixel group 411. For example, the position corresponding to the first row and the second column of the first pixel group 411 may be defined as the second channel of the first pixel group 411, and the pixel R01 may be defined as being disposed in the second channel of the first pixel group 411. For example, the position corresponding to the second row and the first column of the first pixel group 411 may be defined as the third channel of the first pixel group 411, and the pixel R10 may be defined as being disposed in the third channel of the first pixel group 411. For example, the position corresponding to the second row and the second column of the first pixel group 411 may be defined as the fourth channel of the first pixel group 411, and the pixel R11 may be defined as being disposed in the fourth channel of the first pixel group 411.

[0067] In an example, a position corresponding to the first row and the first column of the second pixel group 412 may be defined as a first channel of the second pixel group 412, and the pixel G02 may be defined as being disposed in the first channel of the second pixel group 412. For example, a position corresponding to the first row and the second column of the second pixel group 412 may be defined as a second channel of the second pixel group 412, and the pixel G03 may be defined as being disposed in the second channel of the second pixel group 412. For example, a position corresponding to the second row and the first column of the second pixel group 412 may be defined as a third channel of the second pixel group 412, and the pixel G12 may be defined as being disposed in the third channel of the second pixel group 412. For example, a position corresponding to the second row and the second column of the second pixel group 412 may be defined as a fourth channel of the second pixel group 412, and the pixel G13 may be defined as being disposed in the fourth channel of the second pixel group 412. Positions of the first channel to the fourth channel in another pixel group including the third pixel group or the fourth pixel group may be defined similarly to those discussed for the first pixel group and the second pixel group.

[0068] In an example, the PUF data generation unit 200 may output response data RDATA by receiving image data IDATA and challenge data CDATA. In this case, the challenge data CDATA may include information specifying the position of at least one pixel included in the pixel array 410 including the quaternion pattern. The PUF data generation unit 200 may select a pixel specified based on the challenge data CDATA and a pixel corresponding to the specified pixel through the PUF pixel selection unit 210, extract noise values ​​of the specified pixel and the selected pixel through the noise extraction unit 220, and generate PUF data by comparing the extracted noise value through the response data output unit 230 and output the generated PUF data as the response data RDATA.

[0069] For example, the challenge data CDATA may include information specifying a first channel of the first pixel group 411. In this case, the pixel R00 disposed in the first channel of the first pixel group 411 may be specified based on the challenge data CDATA. When the pixel R00 is specified, the PUF pixel selection unit 210 may select a pixel R04 corresponding to the same color filter as the pixel R00 and disposed in the same channel as the pixel R00. The noise extraction unit 220 may extract noise data of the pixel R00 and noise data of the pixel R04. The response data output unit 230 may generate each bit of the PUF data by comparing the noise data of the pixel R00 and the noise data of the pixel R04. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R04, the response data output unit 230 may determine the first bit of the PUF data to be 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R04, the response data output unit 230 may determine the first bit of the PUF data to be 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0070] For example, the challenge data CDATA may include information specifying a first channel of the first pixel group 411 and information specifying a first channel of the second pixel group 412. In this case, according to the challenge data CDATA, the pixel R00 disposed in the first channel of the first pixel group 411 may be specified and the pixel G02 disposed in the first channel of the second pixel group 412 may be specified. When the pixel R00 and the pixel G02 are specified, the PUF pixel selection unit 210 may select a pixel R04 corresponding to the same color filter as the pixel R00 and disposed in the same channel as the pixel R00, and may select a pixel G06 corresponding to the same color filter as the pixel G02 and disposed in the same channel as the pixel G02. The noise extraction unit 220 may extract noise data of the pixel R00 and noise data of the pixel R04, and may extract noise data of the pixel G02 and noise data of the pixel G06. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R04, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R04, the response data output unit 230 may determine the first bit of the PUF data as 0. Similarly, when the noise data of the pixel G02 is greater than or equal to the noise data of the pixel G06, the response data output unit 230 may determine the second bit of the PUF data as 1, and when the noise data of the pixel G02 is less than the noise data of the pixel G06, the response data output unit 230 may determine the second bit of the PUF data as 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0071] Reference Figure 6 , the imaging device 10 may generate PUF data in a pixel array 420 including a nine-element pattern. The nine-element pattern groups the color filters into a 3x3 matrix, and each pixel group includes a set of pixels having the same color filter and arranged in a 3x3 matrix. For example, the pixel array 420 includes a first pixel group 421 corresponding to a red filter, a second pixel group 422 corresponding to a green filter, a third pixel group 423 corresponding to a red filter, and a fourth pixel group 424 corresponding to a green filter, and each pixel group has pixels arranged in three columns and three rows.

[0072] In an example, the PUF data generation unit 200 may output response data RDATA by receiving image data IDATA and challenge data CDATA. In this case, the challenge data CDATA may include information specifying the position of at least one pixel included in the pixel array 420 including the nine-element pattern. The PUF data generation unit 200 may select a pixel specified based on the challenge data CDATA and a pixel corresponding to the specified pixel through the PUF pixel selection unit 210, extract noise values ​​of the specified pixel and the selected pixel through the noise extraction unit 220, and generate PUF data by comparing the extracted noise value through the response data output unit 230 and output the generated PUF data as the response data RDATA.

[0073] For example, the challenge data CDATA may include information specifying the first row and the first column of the pixel array 420 including the nine-element pattern. In this case, the pixel R00 set in the first row and the first column may be specified based on the challenge data CDATA. When the pixel R00 is specified, the PUF pixel selection unit 210 may select the pixel R10 including the color filter of the same color as the color filter of the pixel R00. The noise extraction unit 220 may extract the noise data of the pixel R00 and the noise data of the pixel R10. The response data output unit 230 may generate each bit of the PUF data by comparing the noise data of the pixel R00 and the noise data of the pixel R10. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R10, the response data output unit 230 may determine the first bit of the PUF data to be 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R10, the response data output unit 230 may determine the first bit of the PUF data to be 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0074] For example, the challenge data CDATA may include information specifying the first row and the first column and the first row and the fourth column of the pixel array 420 including the nine-element pattern. In this case, according to the challenge data CDATA, the pixel R00 set in the first row and the first column may be specified and the pixel G03 set in the first row and the fourth column may be specified. When the pixel R00 and the pixel G03 are specified, the PUF pixel selection unit 210 may select the pixel R10 including the color filter of the same color as the color filter of the pixel R00 and the pixel G13 including the color filter of the same color as the color filter of the pixel G03. The noise extraction unit 220 may extract the noise data of the pixel R00 and the noise data of the pixel R10, and may extract the noise data of the pixel G03 and the noise data of the pixel G13. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R10, the response data output unit 230 may determine the first bit of the PUF data to be 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R10, the response data output unit 230 may determine the first bit of the PUF data to be 0. Likewise, when the noise data of the pixel G03 is greater than or equal to the noise data of the pixel G13, the response data output unit 230 may determine the second bit of the PUF data to be 1, and when the noise data of the pixel G03 is less than the noise data of the pixel G13, the response data output unit 230 may determine the second bit of the PUF data to be 0. When the respective bits of the PUF data are determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0075] In an example, the pixel array 420 including the nine-element pattern may include a first pixel group 421 to a fourth pixel group 424. Among the pixels included in the pixel array 420 including the nine-element pattern, the pixel group may include the same color filter and may be defined as a set of pixels arranged in a 3x3 matrix. Each pixel group may correspond to a unit group of the nine-element pattern. For example, among the pixels included in the pixel array 420 including the nine-element pattern, the first pixel group 421 may include an R color filter and may include pixels R00, R01, R02, R10, R11, R12, R20, R21, and R22 arranged in a 3x3 matrix. Similarly, among the pixels included in the pixel array 420 including the nine-element pattern, the second pixel group 422 may include a G color filter and may include pixels G03, G04, G05, G13, G14, G15, G23, G24, and G25 arranged in a 3x3 matrix.

[0076] The positions of the pixels included in the respective pixel groups (e.g., 421 to 424) may be divided into the first channel to the ninth channel. For example, the position corresponding to the first row and the first column of the first pixel group 421 may be defined as the first channel of the first pixel group 421, and the pixel R00 may be defined as being disposed in the first channel of the first pixel group 421. For example, the position corresponding to the first row and the second column of the first pixel group 421 may be defined as the second channel of the first pixel group 421, and the pixel R01 may be defined as being disposed in the second channel of the first pixel group 411. For example, the position corresponding to the first row and the third column of the first pixel group 421 may be defined as the third channel of the first pixel group 421, and the pixel R02 may be defined as being disposed in the third channel of the first pixel group 421. For example, the position corresponding to the second row and the first column of the first pixel group 421 may be defined as the fourth channel of the first pixel group 421, and the pixel R10 may be defined as being disposed in the fourth channel of the first pixel group 421. For example, a position corresponding to the second row and the second column of the first pixel group 421 may be defined as the fifth channel of the first pixel group 421, and the pixel R11 may be defined as being disposed in the fifth channel of the first pixel group 421. For example, a position corresponding to the second row and the third column of the first pixel group 421 may be defined as the sixth channel of the first pixel group 421, and the pixel R12 may be defined as being disposed in the sixth channel of the first pixel group 421. For example, a position corresponding to the third row and the first column of the first pixel group 421 may be defined as the seventh channel of the first pixel group 421, and the pixel R20 may be defined as being disposed in the seventh channel of the first pixel group 421. For example, a position corresponding to the third row and the second column of the first pixel group 421 may be defined as the eighth channel of the first pixel group 421, and the pixel R21 may be defined as being disposed in the eighth channel of the first pixel group 421. For example, a position corresponding to the third row and the third column of the first pixel group 421 may be defined as the ninth channel of the first pixel group 421, and the pixel R22 may be defined as being disposed in the ninth channel of the first pixel group 421. Even in other pixel groups including the second pixel group 422, the positions of the first to ninth channels may be similarly defined.

[0077] In an example, the PUF data generation unit 200 may output response data RDATA by receiving image data IDATA and challenge data CDATA. In this case, the challenge data CDATA may include information specifying the position of at least one pixel included in the pixel array 420 including the nine-element pattern. The PUF data generation unit 200 may select a pixel specified based on the challenge data CDATA and a pixel corresponding to the specified pixel through the PUF pixel selection unit 210, extract noise values ​​of the specified pixel and the selected pixel through the noise extraction unit 220, and generate PUF data by comparing the extracted noise value through the response data output unit 230 and output the generated PUF data as the response data RDATA.

[0078] For example, the challenge data CDATA may include information specifying a first channel of the first pixel group 421. In this case, the pixel R00 disposed in the first channel of the first pixel group 421 may be specified based on the challenge data CDATA. When the pixel R00 is specified, the PUF pixel selection unit 210 may select a pixel R06 including the same color filter as the pixel R00 and disposed in the same channel as the pixel R00. The noise extraction unit 220 may extract noise data of the pixel R00 and noise data of the pixel R06. The response data output unit 230 may generate each bit of the PUF data by comparing the noise data of the pixel R00 and the noise data of the pixel R06. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R06, the response data output unit 230 may determine the first bit of the PUF data to be 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R06, the response data output unit 230 may determine the first bit of the PUF data to be 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0079] For example, the challenge data CDATA may include information specifying a first channel of the first pixel group 421 and information specifying a first channel of the second pixel group 422. In this case, according to the challenge data CDATA, the pixel R00 disposed in the first channel of the first pixel group 421 may be specified and the pixel G03 disposed in the first channel of the second pixel group 422 may be specified. When the pixel R00 and the pixel G03 are specified, the PUF pixel selection unit 210 may select a pixel R06 corresponding to the same color filter as the pixel R00 and disposed in the same channel as the pixel R00, and may select a pixel G09 corresponding to the same color filter as the pixel G03 and disposed in the same channel as the pixel G03. The noise extraction unit 220 may extract noise data of the pixel R00 and noise data of the pixel R06, and may extract noise data of the pixel G03 and noise data of the pixel G09. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R06, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R06, the response data output unit 230 may determine the first bit of the PUF data as 0. Similarly, when the noise data of the pixel G03 is greater than or equal to the noise data of the pixel G09, the response data output unit 230 may determine the second bit of the PUF data as 1, and when the noise data of the pixel G03 is less than the noise data of the pixel G09, the response data output unit 230 may determine the second bit of the PUF data as 0. When each bit of the PUF data is determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0080] For example, the challenge data CDATA may include information specifying a first channel of the first pixel group 421, information specifying a second channel of the first pixel group 421, and information specifying a third channel of the first pixel group 421. In this case, a pixel R00 disposed in the first channel of the first pixel group 421, a pixel R01 disposed in the second channel of the first pixel group 421, and a pixel R02 disposed in the third channel of the first pixel group 421 may be specified according to the challenge data CDATA. When the pixel R00, the pixel R01, and the pixel R02 are specified, the PUF pixel selection unit 210 may select a pixel R06 corresponding to the same color filter as the pixel R00 and disposed in the same channel as the pixel R00, a pixel R07 corresponding to the same color filter as the pixel R01 and disposed in the same channel as the pixel R01, and a pixel R08 corresponding to the same color filter as the pixel R02 and disposed in the same channel as the pixel R02. The noise extraction unit 220 may extract the noise data of the pixel R00 and the noise data of the pixel R06, the noise data of the pixel R01 and the noise data of the pixel G07, and the noise data of the pixel R02 and the noise data of the pixel G08. When the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R06, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R06, the response data output unit 230 may determine the first bit of the PUF data as 0. In addition, when the noise data of the pixel R01 is greater than or equal to the noise data of the pixel R07, the response data output unit 230 may determine the second bit of the PUF data as 1, and when the noise data of the pixel R01 is less than the noise data of the pixel R07, the response data output unit 230 may determine the second bit of the PUF data as 0. Likewise, when the noise data of the pixel R02 is greater than or equal to the noise data of the pixel R08, the response data output unit 230 may determine the third bit of the PUF data to be 1, and when the noise data of the pixel R02 is less than the noise data of the pixel R08, the response data output unit 230 may determine the third bit of the PUF data to be 0. When the respective bits of the PUF data are determined, the response data output unit 230 may output the PUF data as the response data RDATA.

[0081] The method of generating PUF data according to an embodiment of the present disclosure may be applied to a pixel array having another pattern, including a hexadecimal pattern, in which pixels including the same color filter among pixels included in the pixel array are arranged in a 4×4 matrix form.

[0082] Figure 7 is a diagram for describing the shift of noise values ​​corresponding to color filters.

[0083] Reference Figure 7, the sum of all signals including noise of pixels having a blue (B) color filter and the sum of all signals including noise of pixels having a green (G) color filter may be indicated according to the positions of the pixels.

[0084] In an example, the distribution of pixel data of pixels including the first color filter may be higher than the distribution of pixel data of pixels including the second color filter by an offset value. Such distribution characteristics are due to various factors, such as lens characteristics, crosstalk, or absorption or reflection of incident light wavelengths.

[0085] For example, the distribution of pixel data of pixel 500 including a B filter may be formed to have a higher offset value than the distribution of pixel data of pixel 510 including a G filter. If a first pixel includes a G filter, when a second pixel adjacent to the first pixel includes a B filter, the sum of all signals including noise of the first pixel may have a lower offset value than the sum of all signals including noise of the second pixel. If a third pixel includes a G filter, when a fourth pixel adjacent to the third pixel includes a B filter, the sum of all signals including noise of the third pixel may have a lower offset value than the sum of all signals including noise of the fourth pixel.

[0086] In an example, if the distribution of pixel data has a difference in offset value based on a color filter, PUF performance may be degraded because the output of response data RDATA with respect to the input of challenge data CDATA may be expected regardless of the noise value of the pixel.

[0087] For example, return reference Figure 4 , if pixel G10 is designated according to challenge data CDATA and PUF pixel selection unit 210 selects pixel B11 according to pixel G10, pixel data of pixel G10 may be lower than pixel data of pixel B11 by an offset value because pixel G10 includes a G color filter, pixel B11 includes a B color filter, and pixel G10 and pixel B11 are disposed adjacent to each other. In this case, regardless of the noise value of pixel G10 and the noise value of pixel B11, response data output unit 230 may generate constant PUF data and may output the generated PUF data as response data RDATA.

[0088] For example, when the noise data of the pixel G10 is greater than or equal to the noise data of the pixel B11, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the noise data of the pixel G10 is less than the noise data of the pixel B11, the response data output unit 230 may determine the first bit of the PUF data as 0. However, when the pixel data of the pixel G10 is smaller than the pixel data of the pixel B11 by an offset value, the response data output unit 230 may determine the first bit of the PUF data as 0 regardless of at least one RTN, at least one FPN, or a threshold voltage value of a corresponding transistor included in each noise data of the pixel G10 and the pixel B11. In this case, the response data RDATA may be expected or obtained because the value of the determined PUF data may be determined as a constant value. For example, since the noise value of the pixel G10 is expected to be lower than the noise value of the pixel B11, the PUF data may be expected to be 0, and the response data RDATA may be expected based on the expected PUF data.

[0089] In an embodiment of the present disclosure, if the PUF pixel selection unit 210 specifies a first pixel based on the challenge data CDATA, the PUF pixel selection unit 210 selects a second pixel including the same color filter as the first pixel, thereby removing the offset effect between the pixel data of the first pixel and the pixel data of the second pixel. Therefore, the response data output unit 230 can generate PUF data without being affected by the offset effect, and output the generated PUF data as the response data RDATA.

[0090] In an example, due to various factors such as lens characteristics, crosstalk, or absorption or reflection of a wavelength of incident light, distribution of pixel data of pixels disposed in a first channel may be higher than distribution of pixel data of pixels disposed in a second channel by a higher offset value.

[0091] For example, if a first pixel is set in a first channel of a first pixel group and a second pixel corresponding to the first pixel is set in a second channel of a second pixel group, the sum of all signals including noise of the first pixel may be lower than the sum of all signals including noise of the second pixel by a lower offset value.

[0092] In an example, if distribution of pixel data based on channels of pixel groups has a difference equivalent to an offset value, PUF performance may deteriorate because output of response data RDATA relative to input of challenge data CDATA may be expected regardless of noise values ​​of pixels.

[0093] For example, return reference Figure 5, if the pixel R00 is designated according to the challenge data CDATA and the PUF pixel selection unit 210 selects the pixel R15 according to the pixel R00, the pixel data of the pixel R00 may be lower than the pixel data of the pixel R15 by an offset value because the pixel R00 is set in the first channel of the first pixel group 411 and the pixel R15 is set in the fourth channel of the third pixel group 413. In this case, the response data output unit 230 may generate constant response data RDATA because the response data output unit 230 determines the PUF data regardless of the noise value of the pixel R00 and the noise value of the pixel R15.

[0094] For example, when the noise data of the pixel R00 is greater than or equal to the noise data of the pixel R15, the response data output unit 230 may determine the first bit of the PUF data as 1, and when the noise data of the pixel R00 is less than the noise data of the pixel R15, the response data output unit 230 may determine the first bit of the PUF data as 0. However, if the pixel data of the pixel R00 is lower than the pixel data of the pixel R15 by an offset value, regardless of at least one RTN, at least one FPN, or a threshold voltage value of a corresponding transistor included in each of the noise data of the pixel R00 and the noise data of the pixel R15, the response data output unit 230 may determine the first bit of the PUF data as 0. In this case, the response data RDATA may be expected because the value of the determined PUF data may be determined as a constant value.

[0095] In an embodiment of the present disclosure, if the PUF pixel selection unit 210 specifies a first pixel based on the challenge data CDATA, the PUF pixel selection unit 210 may select a second pixel disposed in the same channel as the first pixel, thereby removing the offset effect between the pixel data of the first pixel and the pixel data of the second pixel. Therefore, the response data output unit 230 may generate PUF data without being affected by the offset effect, and output the generated PUF data as the response data RDATA.

[0096] Cross-reference to related applications and priority claim

[0097] This patent document claims the benefit of Korean Application No. 10-2023-0132589, filed on October 5, 2023, in the Korean Intellectual Property Office, which is incorporated herein by reference in its entirety.

Claims

1. An imaging device, comprising: a physical unclonable function (PUF) pixel selection unit that identifies a first pixel designated to generate PUF data and selects a second pixel having the same color as the first pixel; a noise extraction unit, the noise extraction unit being coupled to the PUF pixel selection unit to receive information of the first pixel and the second pixel, and extracting a first noise value of the first pixel and a second noise value of the second pixel; as well as A PUF data generating unit is coupled to the noise extracting unit and generates the PUF data based on the first noise value and the second noise value from the noise extracting unit.

2. The imaging device according to claim 1, wherein: The second pixel is disposed at a distance of at least two pixels from a center of the first pixel. 3 . The imaging device according to claim 1 , further comprising a first pixel group including the first pixel and at least one pixel adjacent to the first pixel and having the same color as that of the first pixel.

4. The imaging device according to claim 3, wherein: The first pixel is arranged in a first channel of the first pixel group, and The second pixel is arranged in a first channel of a second pixel group, wherein the first channel indicates a position of a specific row and a specific column of a corresponding pixel group.

5. The imaging device according to claim 3, wherein: The first pixel group includes a four-element Bayer pattern in which pixels having filters of the same color are arranged in a 2x2 array, a nine-element pattern in which the pixels are arranged in a 3x3 array, or a sixteen-element pattern in which the pixels are arranged in a 4x4 array.

6. The imaging device according to claim 1, wherein: The first noise value comprises at least one of a fixed pattern noise FPN or a random telegraph noise RTN of the first pixel, and The second noise value includes at least one of FPN or RTN of the second pixel.

7. The imaging device according to claim 6, wherein: The first noise value includes a threshold voltage value of at least one transistor corresponding to the first pixel, and The second noise value includes a threshold voltage value of at least one transistor corresponding to the second pixel.

8. The imaging device according to claim 1, wherein: The PUF data generation unit determines a level of a first bit of the PUF data as a first logic level or a second logic level based on a comparison result between the first noise value and the second noise value.

9. The imaging device according to claim 1, wherein: The PUF pixel selection unit further selects a fourth pixel having the same color as a third pixel designated to generate the PUF data.

10. The imaging device according to claim 9, wherein: The noise extraction unit extracts a third noise value of the third pixel and extracts a fourth noise value of the fourth pixel.

11. The imaging device according to claim 10, wherein: The PUF data generation unit determines a level of a second bit of the PUF data as a first logic level or a second logic level based on a comparison result between the third noise value and the fourth noise value.

12. The imaging device according to claim 10, wherein: The third noise value includes at least one of FPN, RTN of the third pixel, or a threshold voltage of at least one transistor corresponding to the third pixel, and The fourth noise value includes at least one of FPN, RTN of the fourth pixel, or a threshold voltage of at least one transistor corresponding to the fourth pixel.

13. The imaging device according to claim 9, wherein: A distance between the third pixel and the fourth pixel is the same as a distance between the first pixel and the second pixel.

14. The imaging device according to claim 9, wherein: The position of the channel of the third pixel and the position of the channel of the fourth pixel are identical to each other, and the channels indicate the position of a specific row and a specific column of a corresponding pixel group.

15. A method for processing an image signal, the method comprising the following steps: selecting a first pixel in the pixel array based on challenge data specifying a position of at least one pixel of the pixel array; selecting a second pixel in the pixel array having the same color as the first pixel; extracting a noise value of each of the first pixel and the second pixel; as well as Response data is generated by comparing the noise value of the first pixel and the noise value of the second pixel.

16. The method according to claim 15, wherein: The second pixel is arranged at a distance of at least two pixels from the first pixel.

17. The method according to claim 15, wherein: The second pixel is disposed in the same channel as that of the first pixel, the channel indicating a position of a specific row and a specific column of a corresponding pixel group.

18. The method according to claim 15, further comprising the steps of: selecting a third pixel based on the challenge data; and A fourth pixel having the same color as the third pixel is selected.

19. The method according to claim 15, wherein: The step of extracting the noise value comprises the following steps: extracting a first noise value based on at least one of a fixed pattern noise FPN or a random telegraph noise RTN of the first pixel; and A second noise value is extracted based on at least one of the FPN or the RTN of the second pixel.

20. The method according to claim 15, wherein: The step of generating the response data comprises the following steps: generating first comparison data by comparing a noise value of the first pixel and a noise value of the second pixel; and A level of a first bit of the response data is determined to be a first logic level or a second logic level based on the first comparison data.

Images