TWI497297B - Portable storage device and its data security control method - Google Patents

Description

Portable storage device and data security control method thereof

The present invention relates to a portable storage device and a control method thereof, and more particularly to a portable storage device and a data security control method thereof for improving the writing speed by the cache function and ensuring the security of accessing data.

Portable storage devices, commonly known as flash drives, mainly use flash memory as a storage medium, and most of them use a universal serial bus (hereinafter referred to as USB) that supports plug-and-play as a communication interface to the host. Due to the improvement of flash memory manufacturing technology, the capacity of portable storage devices has been continuously expanded, and now it has reached tens of G. Due to the large capacity and USB support plug and play, it is convenient to carry and exchange files and operate. It is also very convenient, so it is widely favored by computer users.

Since the portable storage medium is usually used to carry and exchange files, the flash memory system is frequently deleted and written repeatedly, causing the storage space of the flash memory to be scattered, thereby affecting the portable storage device. Write speed. A viable solution is to absorb the concept of "cache", so that data can be quickly written, and then moved to each of the scattered storage space, so as to improve the efficiency of writing, but must consider: In the process of performing the cache by the portable storage device, it is necessary to ensure the complete transfer of the data in order to prevent the data from being written incorrectly. Therefore, how to balance the speed of writing without affecting the security and correctness of the information, that is, to review and seek A viable solution.

Therefore, the main purpose of the present invention is to provide a data security control method for a portable storage device, which enables the portable storage device to adopt a cache function to increase the writing speed and provide access restriction protection for the portable storage device. Ensure the integrity and correctness of the data during the operation of the portable storage device.

The main technical means for achieving the foregoing objective is to provide a portable storage device having a controller, a non-volatile memory and a communication interface, the non-volatile memory and the communication interface. Each is connected to the controller, and the non-volatile memory has a data storage area and a cache data area; the portable storage device is connected to a host through the communication interface thereof; and according to whether the host has a data security control driver To determine its access rights to the non-volatile memory provided in the portable storage device; the foregoing method is to plan a cache data area in the non-volatile memory of the portable storage device for fast writing Data is then transferred to the data storage area in time. To ensure the correctness of the non-volatile memory data, a data security control driver is installed on the host to integrate the data storage area and the data area of the cache data area. After the portable storage device is connected to a host, it is determined whether the host has the data security control driver, and if the host does not install the data security control Driver, said its non-integrated data functions, thus limiting their access rights, in order to avoid erroneous data store is written Enter data to ensure the security and correctness of the information.

Another object of the present invention is to provide a portable storage device with a cache function to increase the writing speed and an access authority control function to ensure data integrity during the operation of the portable storage device cache function. Correctness.

The main technical means for achieving the foregoing objective is that the portable storage device comprises: a non-volatile memory having a data storage area and a cache data area; and a controller connected to the non-volatile memory. And setting access rights to the data storage area and the cache data area; a communication interface is connected to the controller; and the controller is configured to change an access data storage area according to whether an access permission request is received through the communication interface And accessing the data area; the portable storage device is to plan a cache data area in the non-volatile memory for fast data writing, and then transfer to the data storage area; when a host is installed a data security control driver that can send an access permission request to the connected portable storage device, and can integrate the data storage area and the cache data area after the portable storage device responds to the request; After the portable storage device is connected to a host, the controller determines whether the connected host sends the access permission request, and if the host does not send the access permission request It means that the information security controls driver is not installed, nor with data integration functionality, thus limiting their access, thereby avoids data store is incorrectly written data, and ensure the security and accuracy of the information.

10‧‧‧ Controller

20‧‧‧ Non-volatile memory

21‧‧‧data storage area

22‧‧‧Cache data area

30‧‧‧Communication interface埠

40‧‧‧Host

1 is a block diagram of a preferred embodiment of the present invention.

2 is a block diagram of a preferred embodiment of the present invention connected to a host.

3 is a flow chart of a preferred embodiment of the present invention.

A preferred embodiment of the portable storage device of the present invention, as shown in FIG. 1, includes a controller 10, a non-volatile memory 20, and a communication interface 30;

The controller 10 has a plurality of data pins, address pins, and input and output pins. The data pins and address pins are connected to the non-volatile memory 20, and the input and output pins are connected to the communication interface. 30 connection; the communication interface 30 can be, but not limited to, a USB interface.

The non-volatile memory 20 has a data storage area 21 and a cache data area 22, and the data storage area 21 has a larger storage space than the cache data area 22, wherein the data storage area 21 is for accessing data and a cache data area. The 22 series cooperates with the controller 10 to perform a data cache function, and does not provide a user with access to data. The data cache refers to a portable storage device connected to a host 40 (see FIG. 2), and when the host 40 is installed with a data security control driver capable of identifying the data cache function, the host 40 is When the data is to be written to the data storage area 21, the controller 10 first writes the data to the cache data area 22. Since the cache data area 22 provides a continuous storage space, the write speed can be increased, and the host 40 is When the data is not written, the controller 10 writes the data in the cache data area 22 back to the data storage area 21 in a timely manner, since the controller 10 does not immediately and completely The data in the data area 22 is moved back to the data storage area 21, so the same file may be dispersed in the data storage area 21 and the cache data area 22 at a certain point in time, and this situation may also occur in the portable storage device. After exiting the host 40. When the portable storage device is connected to another host, but the connected host does not have the aforementioned data security control driver installed, the host cannot cooperate with the cache function, and only the content of the data storage area 21 can be seen. If the content of the data storage area 21 is incomplete, if the data is written into the data storage area 21, the data will be incorrect.

In order to ensure the correctness and completeness of the data, the portable storage device will restrict access to the host without the data security control driver to ensure that the data in the data storage area 21 is not damaged. The specific technical means is that an access permission control program is built in the controller 10. When the portable storage device is connected to a host by using the communication interface 30, the controller 10 determines that the host has installed the data security control driver. If the host has installed the data security control driver, an access permission request will be sent, and the controller 10 can determine whether the host has installed the data security control driver according to whether the access permission request is received through the interface interface 30.

When the portable storage device is connected to the host, if the access permission request is not received, it indicates that the host does not install the data security control driver, and the host is restricted to the content of the data storage area 21 in the non-volatile memory 20. Access rights, possible ways to restrict access rights include:

1. Access Disable: The controller 10 completely disables the host from accessing data to its non-volatile memory 20.

2. Read only: The data storage area 21 is set to be read only by the controller 10, and the host can only read the data of the data storage area 21, but cannot write the data. In order to avoid damage to the data in the data storage area 21.

If the controller 10 determines that the host 40 has installed the data security control driver, the access of the non-volatile memory 20 is enabled, and the data storage area 21 and the cache data area 22 are displayed by various applications on the host 40 side. Complete information and access to data.

Therefore, the data security control method provided by the present invention includes the following steps (refer to FIG. 3): providing a portable storage device (301), the portable storage device having a cache function; The portable storage device is coupled to a host 40 (302); and based on whether the host 40 has a data security control driver, determines its access rights to the non-volatile memory in the portable storage device (303); The data security control driver enables access to non-volatile memory.

If the host 40 does not have a security control driver installed, an application with full access rights can be installed. When the portable storage device is connected to the host, the user can execute the application on the host to access the A portable storage device with a cache function. The application can provide similar file administrator functions or other applications that have access to files. That is to say, the non-volatile memory provided in the portable storage device can only be accessed by the application executed on the host, and other applications on the host are still restricted from accessing the portable storage device.

It can be seen from the above that the present invention mainly designs a data storage area and a cache data area in the non-volatile memory of the portable storage device, and cooperates with the data security control driver installed on the host side. Write When the data is being executed, the cache function is executed to increase the writing speed. In order to prevent the cached data area of the portable storage device from being completely transferred to the data storage area, the data is not connected to the host without the data security control driver and the data is written in the data storage area; After the controller is connected to the host, it determines whether the connected host has installed the data security control driver. If it is installed, it enables access to the non-volatile memory. If not installed, the host is restricted to non-volatile memory. The access rights of the body to ensure that the data in the data storage area is not damaged, thus ensuring the security and correctness of the data.

10‧‧‧ Controller

20‧‧‧ Non-volatile memory

21‧‧‧data storage area

22‧‧‧Cache data area

30‧‧‧Communication interface埠

Claims (8)

A data security control method for a portable storage device includes: providing a portable storage device having a controller, a non-volatile memory, and a communication interface, the non-volatile memory and the communication interface respectively Connected to the controller, and the non-volatile memory has a data storage area and a cache data area; the portable storage device is connected to a host through its communication interface; and according to whether the host has a data security control driver, Determining its access rights to the non-volatile memory provided in the portable storage device; when the portable storage device receives an access permission request sent by the host, the controller of the portable storage device utilizes The cache data area of the non-volatile memory performs a data cache function to speed up data access. The data security control method of the portable storage device according to claim 1, wherein if the host has the data security control driver, the non-volatile memory is enabled by the controller of the portable storage device to Display complete information about the data storage area and the cache data area. The data security control method of the portable storage device according to claim 2, wherein the controller restricting the access authority means disabling the access of the non-volatile memory. The data security control method of the portable storage device according to claim 2, wherein the controller restricts the access authority to set the non-volatile memory to be read-only. A portable storage device comprising: a non-volatile memory having a data storage area and a cache data a controller connected to the non-volatile memory and having access rights to the data storage area and the cache data area; a communication interface connected to the controller; the controller is based on whether the communication interface is used埠 receiving an access permission request and changing access rights to the data storage area and the cache data area, and when receiving the access permission request, using the cache data area to perform a data cache function to speed up data The speed of access. In the portable storage device of claim 5, when the controller does not receive the access permission request, the access to the data storage area and the cache data area is disabled. In the portable storage device of claim 5, when the controller does not receive the access permission request, the access permission set for the data storage area and the cache data area is read-only. The portable storage device of any one of claims 5 to 7, wherein the communication interface is a universal serial bus (USB).