WO2020151194A1

WO2020151194A1 - Secure storage method based on domestic cryptography chip

Info

Publication number: WO2020151194A1
Application number: PCT/CN2019/094188
Authority: WO
Inventors: 孙玉玺; 秦法林; 杨兴康; 王晓玉; 尹相彦
Original assignee: 山东华芯半导体有限公司
Priority date: 2019-01-24
Filing date: 2019-07-01
Publication date: 2020-07-30
Also published as: CN109840434A

Abstract

A secure storage method based on a domestic cryptography chip. The method comprises: dividing LBA data into a plurality of blocks, and configuring different keys for different blocks to perform encryption and decryption; performing an exclusive OR operation on one key and a domestic cryptography chip ID to generate a new key, performing an exclusive OR operation on the new key and an LBA of the current block to generate encryption and decryption keys for different blocks, and then calculating a Hash result of the new key by means of an SM3 algorithm to generate data of a fixed length, wherein the data is a final encryption and decryption key of the block; and performing key extension and data transmission in parallel. A storage block key is generated each time same is used, and is not stored inside a chip, and even if a certain key is cracked, full-disk data cannot be parsed, thereby greatly enhancing the difficulty of cracking the full-disk data, and enhancing the security of the key and the data.

Description

A safe storage method based on national secret chip

Technical field

The invention relates to a storage method, in particular, a safe storage method based on a national secret chip, belonging to the technical field of data storage.

Background technique

With the country’s independent and controllable needs and development, data security is a key focus of various industries, especially data leakage prevention and cracking prevention, which are key aspects of data security. This solution provides a security memory chip based on national secrets. The encryption method of random key and random algorithm is adopted for different storage areas, and the data is encrypted by different keys and encryption algorithms for different areas. The randomness of the key and the uncertainty of the encryption algorithm are compared with the specific encryption method. The key and the specified encryption algorithm greatly increase the difficulty of data cracking. This solution can be promoted in the field of storage security and has a wide range of application prospects.

Summary of the invention

The technical problem to be solved by the present invention is to provide a secure storage method based on a national secret chip, which uses different keys for different storage blocks. The storage block keys are generated each time they are used and are not stored in the chip, even if Cracking a certain key cannot parse the entire disk data, which greatly increases the difficulty of cracking the entire disk data and enhances the security of the key and data.

In order to solve the technical problem, the technical solution adopted by the present invention is: a secure storage method based on a national secret chip, including the following steps: S01), divide the LBA data into multiple blocks, and configure different blocks for different blocks. S02), the key and the national secret chip ID are XORed to generate a new key, and then the new key is XORed with the LBA of this block to generate specific Block encryption and decryption key, and then use SM3 algorithm to calculate the hash result of the new key to generate fixed-length data, which is the final encryption and decryption key of the block; S03), key expansion and data transmission parallel , In the data transmission stage, obtain the LBA and data length, calculate and configure the key of the LBA block, the national secret chip hardware performs key expansion, and the memory reads or receives the data. After the data is read or received, the data is split package.

Further, when performing encryption calculation, different symmetric encryption algorithms are selected according to the parity of the lowest bit of the final encryption and decryption key of the block.

Further, when performing encryption calculation, SM4 and SM1 algorithms are randomly selected for encryption calculation.

Further, in step S01, every 256 LBAs is a group of 128KB data, the LBA is divided into 3 blocks, and the data header and the data tail fall into the same block or two consecutive blocks after the data is split .

Further, when the data spans two blocks, the second block needs to be configured with a key for key expansion before the data can be transmitted.

The beneficial effects of the present invention: the present invention improves the data security of the entire device through a scheme of using different keys for different storage blocks and randomly selecting encryption algorithms. The storage block key is generated every time it is used, and it does not Stored in the chip, even if a certain key is cracked, the entire disk data cannot be parsed, which greatly enhances the difficulty of cracking the entire disk data and the security of the key. The division and encryption of storage blocks fully consider the behavior of the operating system and the characteristics of the protocol, and do not cause loss of performance. This solution is suitable for fields and industries that require high data security levels, greatly improving data security.

Description of the drawings

Figure 1 is a schematic diagram of continuous reading and writing hand capture under Windows;

Figure 2 is a schematic diagram of continuous reading and writing manual packet capture under Linux;

Figure 3 is a schematic diagram of data splitting;

Figure 4 is a flowchart of key synthesis;

Figure 5 is a flow chart of BOT transmission;

Figure 6 is a flowchart of data encryption in Embodiment 1;

detailed description

The present invention will be further described below in conjunction with the drawings and specific embodiments.

Example 1

This embodiment discloses a secure storage method based on a national secret chip. The model of the national secret chip is HX6802. The chip supports a USB3.0 interface. The internal hardware implements algorithms such as national secret SM1, SM2, SM3, SM4, etc., and has obtained National commercial secret. The data stored in NandFlash is encrypted by the hardware symmetric encryption module of the main control chip, and the data is in cipher text. The encryption and decryption keys are compounded according to the factors of LBA (Minimum Data Operation Unit of Storage Device), chip ID and key. Calculate, form keys for different blocks, and specify different encryption algorithms to enhance data security. Even if a certain part of the key is cracked, the entire disk information cannot be obtained.

The present invention includes the following steps:

S01), LBA data block;

The unit of measurement for storage device writing is LBA, each LBA 512 bytes, and the data transmitted each time must be an integer multiple of the LBA. An important reference for the performance indicators of storage devices is continuous read and write, which is often referred to as seq r/w. If the block is too small, it will cause the firmware to continuously interrupt the NandFlash read and write operations for key configuration and expansion, which will seriously reduce the performance; and if the block is too large, it will reduce the data encryption security. We found through data packet capture that mainstream Windows and Linux systems generally read and write large files that are split into fixed-size packet lengths. See Figure 1 (Continuous Read and Write Packet Capture under Windows) for each 128KB group. 2 (Linux continuous reading and writing packet capture) Each 120KB group is divided into blocks. According to the principle of compatibility, each 256 LBA, that is, 128KB data is used as a group, divided into encryption and decryption blocks, and different encryption and decryption blocks are configured for different encryption and decryption blocks. Key for encryption and decryption.

In this embodiment, the LBA data is divided into 3 blocks. According to the data splitting, there are 3 situations. As shown in Figure 3, 1. The data header falls within the first 128KB block, and the data tail falls on In the second 128KB block; 2. The data header falls in the second 128KB block, and the data tail falls in the third 128KB block; 3. The data header and data tail fall in the second 128KB block Inside. When the data header and the data tail fall in two blocks, it needs to be split twice, and the key is configured twice to write the data into the NandFlash twice. The actual measurement will not affect the continuous read and write performance.

S02), block key generation

Each chip has a unique ID value. In order to increase the randomness, the first step is to perform an XOR operation on the key and the national secret chip ID to generate a new key, and then perform the newly generated key and the LBA of the block XOR operation generates encryption and decryption keys for different encrypted blocks, and then uses SM3 algorithm to calculate the hash result of the new key to generate fixed-length data, which is the final encryption and decryption key of the block. See Figure 4. Each block key is calculated and generated, and the ID of each chip is different. Even if different devices are configured with the same key, the actual key is different. Even if the key is obtained, the method of generating the block key is not known. Unable to obtain the real key.

At the same time, the encryption algorithm selection selects different symmetric encryption algorithms according to the parity of the lowest bit of the block key. When encrypting in this embodiment, two algorithms, SM4 and SM1, are randomly selected, which further increases the difficulty of cracking.

S03), key expansion and data transmission parallel

The mass storage device USB3.0 device is generally based on the BOT protocol, and the flow chart of using SCSI commands for transmission is shown in Figure 5. Key expansion generally takes a certain amount of time, so an optimization measure is adopted. In the CBW stage of data transmission, the LBA and data length are obtained, the key of the block is calculated, and then the key of the first group of blocks is configured first. The hardware performs key expansion, and at the same time, the USB3.0 hardware receives data from the host computer (Data Out), or the NandFlash controller reads data from NandFlash (Data In). After all the data is processed in the hardware FIFO, the data is removed. Package, so in the process of large-capacity data transmission, the key and data serial situation can only be done once at most, that is, when the data spans two blocks, the second time you need to configure the key for key expansion, and then transmit the data This method reduces latency and improves performance.

Example 2

In this embodiment, the encryption process, the distance between the process of writing data from the PC to the USB storage device, and the decryption process are the reverse process of the encryption process, as shown in FIG. 6, including the following steps:

S01), the PC sends the LBA and data transmission volume to the HX6802, and the HX6802 obtains the LBA offset and the data volume LBA range;

S02), HX6802 calculates the key and the synthetic key of LBA, and the synthetic key calls SM3 calculation to generate the block key;

S03), HX6802 selects the encryption method according to the parity of the lowest bit of the synthetic key;

S04) The PC configures the key for key expansion, and sends data to the HX6802;

S05), HX6802 selects an encryption algorithm and performs key extension;

S06), HX6802 splits the data packet, selects the LBA block, hardware encryption, data ciphertext writing, and the transmission is completed;

S07), until all data is written, the instruction is corresponding, and the instruction is completed to the PC.

The data block encryption and decryption, encryption and decryption encryption method and key of the present invention are randomly calculated and generated according to different devices. The data key of each encrypted block is changed, and the data block key is not stored in the device. It is calculated and generated during use. Improve the security level of key protection.

The key is combined with the hash result of the chip ID, block LBA and SM3, and the result is irreversible, which enhances the randomness of the key and the difficulty of cracking.

The actual combination of data block and configuration key extension is the way of mainstream operating systems and the characteristics of the BOT protocol to fully guarantee performance.

What has been described above are only the basic principles and preferred embodiments of the present invention. Improvements and replacements made by the human body in the field according to the present invention belong to the protection scope of the present invention.

Claims

A secure storage method based on a national secret chip, which is characterized in that it includes the following steps: S01), dividing LBA data into multiple blocks, and configuring different keys for different blocks for encryption and decryption; S02), combining The key and the national secret chip ID are XORed to generate a new key, and then the new key is XORed with the LBA of this block to generate encryption and decryption keys for different blocks, and then use the SM3 algorithm Calculate the hash result of the new key to generate fixed-length data, which is the final encryption and decryption key of the block; S03), key expansion is parallel to data transmission, and in the data transmission phase, LBA and data length are obtained , Calculate and configure the key of the LBA block, the national secret chip hardware performs key expansion, and the memory reads or receives data at the same time. After all the data is read or received, the data is unpacked.
The secure storage method based on the national secret chip according to claim 1, characterized in that when performing encryption calculation, different symmetric encryption algorithms are selected according to the parity of the lowest bit of the final encryption and decryption key of the block.
The secure storage method based on a national secret chip according to claim 1, characterized in that when performing encryption calculation, SM4 and SM1 algorithms are randomly selected for encryption calculation.
The secure storage method based on the national secret chip according to claim 1, characterized in that: in step S01, every 256 LBAs, that is, every 128KB of data is a group, the LBAs are divided into 3 blocks, and the data header is split. The data tail falls into the same block or two consecutive blocks.
The secure storage method based on the national secret chip according to claim 1, wherein when the data spans two blocks, the second block needs to be configured with a key for key expansion before the data can be transmitted.