TWI700757B - Encryption and decryption secret key generation method - Google Patents

Abstract

An encryption and decryption secret key generation method which includes steps of: choosing a block of a NAND flash memory; initiating the block of the NAND flash memory; programing the block of the NAND flash memory so as to obtain first electric levels of memory units in the block; re-initiating the block of the NAND flash memory; re-programing the block of the NAND flash memory so as to obtain second electric levels of memory units in the block; subtracting the first electric levels from the second electric levels of the memory units correspondingly so as to obtain a difference form; and reading difference values of the difference form according to a setting sequence to be a encryption and decryption secret key.

Description

Encryption and decryption key generation method

This case relates to a method for generating encryption and decryption keys, and in particular, it relates to a method for generating encryption and decryption keys using reverse and gate flash memory to generate keys.

Data digitization is the current trend, and digitized data can be stored permanently. Once digitized, an important topic derived is "data security." Known data encryption methods, such as HASH, SHA (Secure Hash Algorithm), SSL (Secure Socket Layer), WPA (Wi-Fi Protected Access)... etc., are widely used in different fields. In standard encryption procedures, encryption and decryption methods are easier to crack. Therefore, random numbers need to be added to increase the complexity and improve data security.

As mentioned above, in order to provide random numbers to improve data security, a True Random Number Generator is needed. This circuit uses the changing environment to generate random numbers of different environmental variables. However, the complexity of the random number generated by the existing real random number generator is insufficient, and even if the above random number is used, the digitized data is still in danger of being cracked.

The content of the invention aims to provide a simplified summary of the content of this disclosure so that readers have a basic understanding of the content of this disclosure. This content of the invention is not a complete summary of the content of the present disclosure, and its intention is not to point out the important/key elements of the embodiments of this case or to define the scope of this case.

One purpose of the content of this case is to provide a method for generating encryption and decryption keys, so as to solve the problems in the prior art.

In order to achieve the above purpose, one of the technical aspects of the content of this case relates to a method for generating encryption and decryption keys, which includes the following steps: selecting a block of the flash memory; initializing the flash memory. Block; Programmable anti-and-gate flash memory block to obtain and store the plural first potentials of a plurality of memory cells in the block; re-initialize the anti-and-gate flash memory block; Programmable and gate flash memory blocks to obtain a plurality of second potentials of the memory cells in the block; the first potentials of the memory cells correspond to the second potentials Subtract to obtain a difference table; and read a plurality of difference values in the difference table according to a set sequence to serve as an encryption and decryption key.

Therefore, according to the technical content of this case, the encryption and decryption key generation method shown in the embodiment of this case uses the physical characteristics of flash memory to generate the difference value, which is used as the encryption and decryption key, thereby improving the encryption and decryption key. The complexity of the decryption key. In addition, this case uses a different reading order of the difference value, or uses the limitation of the difference value range to filter out some of the difference values, which further increases the complexity of the encryption key generated in this case.

After referring to the following embodiments, those with ordinary knowledge in the technical field of the case can easily understand the basic spirit of the case and other purposes of the invention, as well as the technical means and implementation aspects of the case.

100: reverse and gate flash memory

11 0: block

200: method

210~270: Step

300: Difference table

D11~Dnm: difference value

M11~Mxy: memory unit

In order to make the above and other objectives, features, advantages and embodiments of this case more obvious and understandable, the description of the accompanying drawings is as follows: Figure 1 shows an array of NAND flash memory according to an embodiment of this case Schematic block diagram.

FIG. 2 is a schematic flowchart of a method for generating encryption and decryption keys according to an embodiment of this case.

FIG. 3 is a schematic diagram of a block of the NAND flash memory shown in FIG. 1 according to an embodiment of the present application.

FIG. 4 is a schematic diagram of the programming operation of the NAND flash memory block shown in FIG. 1 according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of the programming operation of the NAND flash memory block shown in FIG. 1 according to an embodiment of the present invention.

FIG. 6 is a schematic diagram showing the difference value of a NAND flash memory as shown in FIG. 1 according to an embodiment of the present application.

According to the usual working method, the various features and components in the figure are not drawn to scale. The drawing method is to present the specific features and components related to the case in the best way. In addition, between different drawings, the same or similar element symbols are used to refer to similar elements/components.

In order to make the narrative of the contents of this disclosure more detailed and complete, the following provides an illustrative description for the implementation of this case and specific embodiments; but this is not the only way to implement or use the specific embodiments of this case. The implementation manners cover the characteristics of a number of specific embodiments and the method steps and sequences used to construct and operate these specific embodiments. However, other specific embodiments can also be used to achieve the same or equal functions and sequence of steps.

Unless otherwise defined in this specification, the scientific and technical terms used here have the same meaning as understood and used by those with ordinary knowledge in the technical field to which this case belongs. In addition, without conflict with context, the singular nouns used in this specification cover the plural nouns; and the plural nouns also cover the singular nouns.

FIG. 1 is a schematic block diagram of a NAND flash memory 100 array according to an embodiment of the present invention. As shown in the figure, the NAND flash memory 100 includes a plurality of memory cells M11~Mxy, and both x and y are positive integers. To illustrate how to use the physical characteristics of the NAND flash memory 100 to produce encryption and decryption keys, please also refer to Figure 2, which is a schematic flow diagram of an encryption and decryption key generation method 200 according to an embodiment of this case .

Please refer to Figure 2 first, the encryption and decryption key generation method 200 includes the following steps: Step 210: Select a block of NAND flash memory; Step 220: Initialize a block of NAND flash memory; Step 230 : Programmatically reverse and gate the flash memory block to obtain and store a plurality of first potentials of a plurality of memory cells in the block; Step 240: reinitialize the reverse and gate flash memory block; Step 250: Reprogram the blocks of the flash memory to get the second potentials of the memory cells in the block; Step 260: The first potentials of the memory cells Subtract corresponding to the second potentials to obtain a difference table; and step 270: read a plurality of difference values in the difference table according to the set sequence, and use them as encryption and decryption keys.

Please refer to Figure 1 and Figure 2 together for explanation. In step 210, the block 110 of the NAND flash memory 100 is selected. However, this case is not limited to what is shown in Figure 1, and it is only used to illustrate one of the implementation methods of this case. In other embodiments, other parts of the NAND flash memory 100 can also be selected as blocks, for example, the lower left corner part, the upper right corner part, the lower right corner part, the middle part or the NAND flash memory 100 The remaining appropriate parts, in this way, when different parts of the NAND flash memory 100 are selected as blocks, the complexity of the subsequent encryption and decryption keys can be further increased.

In step 220, please also refer to FIG. 3 for description. FIG. 3 shows a schematic diagram of the block 110 of the reverse and gate flash memory 100 shown in FIG. 1 according to an embodiment of the present invention. . As shown in the figure, the block 110 of the NAND flash memory 100 includes a plurality of memory cells M11~Mnm, and both n and m are positive integers. As shown in step 220, the block 110 of the NAND flash memory 100 is initialized. For example, the above-mentioned initialization method may be to erase the data of the memory cells M11~Mnm in the block 110 of the flash memory 100.

Next, perform step 230. Please also refer to FIG. 4 for description. FIG. 4 shows an example shown in FIG. 1 according to an embodiment of the present invention. A schematic diagram of the programming operation of the block 110 of the flash memory 100 in reverse. As shown in step 230, the block 110 of the NAND flash memory 100 is programmed to obtain and store a plurality of first potentials of the memory cells M11~Mnm in the block 110. For example, the above-mentioned programmed operation can be to write a high potential into the memory cells M11~Mnm in the block 110 of the NAND flash memory 100. Please refer to Figure 4, in the figure, the potential of the memory cell M11~Mnm is represented by a dot matrix. The denser the dot matrix, the higher the potential. It should be noted that due to slight differences in materials, manufacturing processes, etc., generally speaking, the characteristics of each memory cell M11~Mnm will be different. Therefore, even if the same high potential is given, the memory cell M11~Mnm The potential is still different. This case uses such physical characteristics to generate a highly complex encryption and decryption key, which will be described in further detail later.

Please refer to step 240 to reinitialize the block 110 of the NAND flash memory 100, for example, re-erase the data of the memory cells M11~Mnm in the block 110 of the NAND flash memory 100. Then, perform step 250. Please also refer to FIG. 5 for description. FIG. 5 shows a block 110 of the gate flash memory 100 as shown in FIG. 1 according to an embodiment of the present invention. Sketch map of stylized operation. As shown in step 250, the block 110 of the NAND flash memory 100 is re-programmed to obtain a plurality of second potentials of the memory cells M11~Mnm in the block 110. For example, the above-mentioned programmed operation can be to write a high potential into the memory cells M11~Mnm in the block 110 of the NAND flash memory 100. As shown in Figure 5, after writing a high potential, the power of the memory cell M11~Mnm The potential is still different, and after the high potential is written in Figure 4, the potentials of the memory cells M11~Mnm are different.

In step 260, the first potentials and the second potentials of the memory cells M11~Mnm are correspondingly subtracted to obtain a difference table. For example, subtract the potential exhibited by the memory cells M11~Mnm shown in Figure 4 from the potential exhibited by the corresponding memory cells M11~Mnm in Figure 5 to obtain the potential shown in Figure 6.的 Difference Table 300. In detail, by subtracting the potential of the memory cell M11 in Figure 4 from the potential of the memory cell M11 in Figure 5, the difference value D11 in Figure 6 will be obtained. The other memory cells can also use the above method To get the difference value. If all the difference values are collected, the difference table 300 shown in Fig. 6 can be obtained. It should be noted that not all memory cells exhibit different potentials during two programming. For example, memory cell M12 has the same potential after two programming. Therefore, there is no difference value D12 (without The difference value is marked in white here, but the embodiment in Fig. 6 is only for illustration and does not limit this case).

Subsequently, step 210 is performed to read the plurality of difference values in the difference table 300 according to the set sequence, and use them as encryption and decryption keys. For example, if the difference value D11 is 255 and the difference value D14 is 127, the encryption and decryption key can be 255127. However, this case is not limited to this. It only exemplarily illustrates one of the implementation methods of this case to facilitate understanding. There are still many difference values in the follow-up difference table 300. If these difference values are composed of the above encryption and decryption keys, the encryption and decryption keys The complexity of the key is very high, and the security for encryption and decryption is good.

In an embodiment, the matrix formed by the block 110 in Fig. 3 to Fig. 5, or a row of the matrix formed by the difference value in Fig. 6 and The matrix unit formed by a column serves as a basic unit. In Fig. 6, the difference value D12 is a matrix unit, which occupies a basic unit of the matrix, and the difference value D13 is also a matrix unit, which occupies a basic unit of the matrix. The encryption and decryption key in this case can further increase the complexity according to the above situation. For example, in addition to the difference value D11 being 255 and the difference value D14 being 127, because the difference value Dl1 and the difference value D14 are separated by two basic units (such as D12, D13) ), therefore, the encryption and decryption key can be formed by the combination of the above difference value and the basic unit. In detail, the encryption and decryption key can be "difference value D11, basic unit 2 (such as D12, D13) ) And the difference value D14", that is, the encryption and decryption key can be 2552127. However, this case is not limited to this. The difference table 300 has many difference values and the basic unit of the interval between the difference values. If the combination of these difference values and the basic unit is used as the encryption and decryption key, the encryption and decryption key The complexity of the key will be further improved, and the security of encryption and decryption will be more guaranteed.

In another embodiment, the setting sequence of reading the difference values in the difference table in step 270 may be: selectively reading the difference values corresponding to the same row of the matrix in the difference table 300, selecting Read the difference values in the difference table 300 corresponding to the same column of the matrix or selectively read the difference values in the difference table 300 corresponding to any row and any column of the matrix, And combine the read difference values with the basic unit values to serve as encryption and decryption keys. Please refer to Figure 6. Taking the same column of the matrix as an example in the reading order, the difference value D11, the basic unit 2 (D12, D13), and the difference value D14 can be read. Therefore, the encryption and decryption key is 2552127. Taking the reading sequence as an example of the same behavior of the matrix, it can read the difference value D11, the basic unit 1 (D21), and the difference value D31. If the difference value D31 is 268, then the encryption key can be obtained. It is 2551268. Taking the reading order as any row and any column of the matrix as an example, it can read the data on the diagonal line of the difference table, such as reading the difference value D11, the basic unit l (D22) and the difference value D33, if the difference value D33 is 525, at this time, the available encryption and decryption key is 2551525. Similarly, this case is not limited to this. The difference table 300 has many difference values and the basic units of the interval between the difference values. If the combination of these difference values and the basic unit is used as the encryption and decryption key, the encryption and decryption will be performed. The complexity of the key can be further improved, and the security of encryption and decryption can be more guaranteed. In addition, the setting sequence of reading the difference values in the difference table described in step 270 is not limited to the above embodiment. When reading, it can also be read at intervals between difference values with differences, for example, difference values with differences. Dl1, D14, D16, D18, Dl9, this case can read the difference values Dl1, D16, Dl9 at intervals, skip the difference values D14, D18, or this case can also read the even difference values D14, D18, or set any required The reading order.

In yet another embodiment, a range of the difference value can be set, for example, the range of the difference value is set to 128-256. If the difference value is not within this range, the difference value will be filtered out, further increasing the complexity of the encryption and decryption keys. For example, taking the same column of the matrix in the reading order as an example, the difference value D11, the basic unit 2 (D12, D13), and the difference value D14 can be read originally. However, the difference value D14 is 127, which exceeds the difference value range 128~256, so in fact, the difference value D14 will not be read, but will continue to look for the difference value of the remaining bits within the difference value range in the same column. Assuming that after 500 basic units, the difference value D1502 is 152( The above D1502 is the first column, row 502), and then, after 50 basic units, the difference value D1553 is 198 (the above D1553 is the first column, row 553), then actually encrypt and decrypt The key will be the combination of the above difference value and the basic unit 25550015250198. The detailed table is as follows: 255/500/152/50/198

D11/interval value/D1502/interval value/D1553

In this way, Dangke once again increases the complexity of the encryption and decryption keys, thereby improving the security of encryption and decryption. It should be noted that the initialization step in Figure 3, the programming step in Figures 4 and 5, and the step of subtracting in Figure 6 to generate a difference value can be performed by electronic devices or other appropriate devices, for example It can be executed by the central processing unit (CPU), microprocessor (MCU) or other appropriate components of the electronic device.

It can be seen from the above implementation of this case that the application of this case has the following advantages. The encryption and decryption key generation method shown in the embodiment of this case uses the physical characteristics of flash memory to generate a difference value as the encryption and decryption key, thereby increasing the complexity of the encryption and decryption key. In addition, this case uses a different reading order of the difference value, or uses the limitation of the difference value range to filter out some of the difference values, which further increases the complexity of the encryption and decryption keys generated in this case.

Although the specific examples of this case are disclosed in the above embodiments, they are not intended to limit the case. Those with ordinary knowledge in the technical field to which this case belongs should not deviate from the principles and spirit of this case. Various changes and modifications have been made. Therefore, the scope of protection in this case shall be subject to the scope of the accompanying patent application.

200‧‧‧Method

210~270‧‧‧Step

Claims (10)

An encryption and decryption key generation method, comprising: selecting a block of a flip and gate flash memory; initializing the block of the flip and gate flash memory; programming the flip and gate flash memory Block to obtain and store the plurality of first potentials of the plurality of memory cells in the block; reinitialize the block of the inverter flash memory; reprogram the inverter flash memory To obtain a plurality of second potentials of the memory cells in the block; correspondingly subtract the first potentials and the second potentials of the memory cells to obtain a difference Table; and read the plurality of difference values in the difference table according to a set sequence to serve as an encryption and decryption key. The encryption and decryption key generation method according to claim 1, wherein the step of initializing the block of the flash memory includes: erasing the blocks of the flash memory Data of the memory unit. The method for generating encryption and decryption keys according to claim 1, wherein the step of programming the block of the NAND flash memory includes: writing a high potential to the block of the NAND flash memory These memory units in the. The method for generating encryption and decryption keys as described in claim 3, wherein the first potential portions corresponding to the memory cells in the block are different. The method for generating encryption and decryption keys according to claim 4, wherein the step of reprogramming the block of the NAND flash memory includes: rewriting the high potential to the NAND flash memory The memory cells in the block. According to the method for generating encryption and decryption keys according to claim 5, the second potential portions corresponding to the memory cells in the block are different. The method for generating encryption and decryption keys according to claim 6, wherein the corresponding subtraction of the first potentials and the second potentials of the memory cells to obtain the difference table includes: the memories The first potential of a first memory cell of one of the memory cells is correspondingly subtracted from the second potential of the first memory cell to obtain a first difference value; one of the memory cells is a second memory The first potential of the cell and the second potential of the second memory cell are correspondingly subtracted to obtain a second difference value; and the difference table is obtained according to the first difference value and the second difference value. The method for generating encryption and decryption keys according to claim 7, wherein the memory cells in the block are arranged in a matrix, wherein a matrix unit formed by one row and one column of the matrix is used as a basic unit, and the difference value Appear once every several basic units, and read the difference values in the difference table according to the setting sequence as the encryption and decryption key. The steps include: reading the difference values in the difference table according to the setting sequence The difference value, and the combination of the difference value and the numerical value of the basic unit is used as the encryption and decryption key. The method for generating encryption and decryption keys according to claim 8, wherein the step of reading the difference values in the difference table as the encryption and decryption keys according to the setting sequence includes: selectively reading the difference The difference values in the table corresponding to the same row of the matrix, selectively reading the difference values corresponding to the same column of the matrix in the difference table, or selectively reading the difference table The difference values corresponding to any row and any column of the matrix are combined, and the read difference values are combined with the numerical values of the basic units to serve as the encryption and decryption key. The encryption and decryption key generation method according to claim 7, wherein the steps of reading the difference values in the difference table as the encryption and decryption key according to the setting sequence include: setting a difference value range; and The difference values within the difference value range in the difference table are read according to the setting sequence to serve as the encryption and decryption keys.

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