CN102054143A - Read-only protection method for removable storage medium - Google Patents

Abstract

The invention is a read-only protection method of removable storage media, establish a write-inhibit data table storing the file name of write-inhibit removable storage media first, when the removable storage media wants to exchange data with the storage device that may be poisoned, can inhibit effectively that any file that may cause the removable storage media poisoning writes into the removable storage media, but other files can still write into normally, in this way, not only can reduce the chance that the removable storage media poisons, and the removable storage media can still write the data that users need, will not cause inconvenience because of possible not allowing to use because of poisoning.

Description

The read-only guard method of removable formula Storage Media

Technical field

The present invention is about a kind of read-only guard method of removable formula Storage Media.

Background technology

In recent years, along with popularizing of removable formula Storage Medias such as the carry-on dish of USB, carry-on hard disk, make the distribution of the carry-on dish virus of USB serious day by day.

The carry-on dish virus of USB mainly is to utilize the autorun.inf file with in the computer that virus is implanted with the removable formula Storage Media of having poisoned is connected, the built-in Storage Media of this computer is infected, by the computer that is infected virus being spread to each again infects in the removable formula Storage Media that computer was connected with this round, therefore, the carry-on dish virus of USB aleopation and constantly diffusion between computer and removable formula Storage Media.

For preventing the continuation diffusion of the carry-on dish virus of USB, the carry-on dish of a kind of prior USB is for further being provided with a read-only switch thereon, switching read-only switch by the user makes the carry-on dish of this USB start read-only function, behind read-only function on, any data all can't write in the carry-on dish of this USB, suffer infective virus when being connected with the computer that infects the carry-on dish virus of USB so can prevent the carry-on dish of USB.

Yet, when read-only function on, though can allow the file that contains virus can't write outside the carry-on dish of this USB, generic-document also can't write the carry-on dish of this USB thus, and the user also can't delete the file in the carry-on dish of USB according to need, causes the user inconvenient greatly.

Summary of the invention

The objective of the invention is to, solve in the prior art,, use inconvenient technical matters by the continuation diffusion that the system switch prevents the carry-on dish virus of USB is set.

For achieving the above object, the invention provides a kind of read-only guard method of removable formula Storage Media, comprise the following steps:

Set up one and forbid writing tables of data, this forbids writing tables of data for storing the file name of forbidding writing a removable formula Storage Media;

Reception is to the write command of removable formula Storage Media, and this write command also comprises the file name of desiring to write removable formula Storage Media;

Judge whether to allow data are write removable formula Storage Media, the file name of desiring to write removable formula Storage Media for comparison forbids writing that tables of data is stored forbids writing file name and whether conform to this;

Tables of data is stored forbids writing file name and do not conform to if the file name of desiring to write removable formula Storage Media forbids writing with this, then allow this write command that data are write removable formula Storage Media, otherwise then do not allow this write command that data are write removable formula Storage Media.

Beneficial effect of the present invention is; utilize above-mentioned technological means, a kind of read-only guard method of removable formula Storage Media is provided, it can still can write under the prerequisite of data removable formula Storage Media; prevent that some specific file from writing in the removable formula Storage Media, with the virus of avoiding infection.Owing to only forbid existing the file name of forbidding writing in the tables of data to write removable formula storage device, therefore this file of forbidding writing file name in the tables of data of non-genus all can normally write removable formula storage device, thus, not only can prevent removable formula Storage Media infective virus, and still can write the required data of user, allow the user not have the restriction that can't write data fully in the use removable formula Storage Media.

Description of drawings

Fig. 1 is the application function calcspar of a preferred embodiment of the present invention.

Fig. 2 is the process flow diagram of a preferred embodiment of the present invention.

Description of reference numerals:

The carry-on dish of 10-USB; The 20-computer.

Embodiment

The read-only guard method of the removable formula Storage Media of the present invention, in order to make one to be connected with computer or the removable formula Storage Media of line has only read-protected function, this removable formula Storage Media can be the storage device of a USB interface, the for example carry-on dish of USB, the carry-on hard disk of USB etc., or other any removable formula Storage Medias that may kenels; Method of the present invention again may be implemented in this to be desired to have on the removable formula Storage Media of a read protecting function, or is implemented on the computer of this removable formula Storage Media desire connection or line.As shown in Figure 1, be implemented on the carry-on dish 10 of a USB as an example with method of the present invention below.

See also shown in Figure 2ly, the first embodiment of the present invention comprises the following steps:

Set up one and forbid writing tables of data 200;

Set up one and forbid deleted data table 201;

Set up a virus behavior tables of data 202;

Check whether the computer that is connected with removable formula Storage Media has potential virus danger 203;

If the computer 20 no potential virus danger that are connected with removable formula Storage Media then allow the read-write 204 to removable formula Storage Media fully, otherwise then proceed the following step;

Reception is to the write command 205 of removable formula Storage Media;

If the write command desire writes removable formula Storage Media with data, then further judge whether to allow data are write removable formula Storage Media 206, if be judged as is then to allow data are write removable formula Storage Media 207, otherwise then do not allow data are write removable formula Storage Media 208;

If the write command desire is deleted data in the removable formula Storage Media, then further judge whether to allow to delete the data 209 of removable formula Storage Media, if be judged as be, then allow the data 210 of the removable formula Storage Media of deletion), on the contrary the data 211 that then do not allow to delete removable formula Storage Media.

Set up one and forbid writing in tables of data 200 steps above-mentioned, this is forbidden writing tables of data and forbids writing file name for storing, this is forbidden writing file name and can be the file full name that comprises main file name (base name) and secondary shelves names (extension), or only is secondary shelves name; Because mostly most of viruses are the secondary shelves name of .exe .com .pif .lnk, thus in present embodiment, with secondary shelves as forbidding that writing file name illustrates.

Set up one and forbid in deleted data table 201 step above-mentioned, this forbids that the deleted data table is to store to forbid the deleted data title, this forbids that the deleted data name is called file full name, secondary shelves name or directory path, for example: some virus may be deleted the file of all secondary shelves .exe by name in the carry-on dish 10 of USB, may be secondary shelves name so forbid the deleted data title; Or should do not deleted arbitrarily when having deposited significant data in certain important catalogue of the carry-on dish 10 of this USB the time, suffer the virus deletion for avoiding this important catalogue, may be the path of this important catalogue so forbid the deleted data title.

Set up in a virus behavior tables of data 202 steps above-mentioned, this virus behavior tables of data is for storing the virus behavior data, and it is put down in writing when computer 20 infective virus, sets condition code and the deposit position thereof that shelves may exist in computer 20 operating systems; Form (Windows) operating system and Virus.Win32.AutoRun.ah virus with Microsoft are example; the logfile of windows workspace system (Registry) is aforesaid setting shelves; and should virus can automatically perform after the windows workspace system starts shooting again for guaranteeing; usually can logfile [HKLM SOFTWARE Microsoft Windows CurrentVersion RunOnce] increase in order to start the machine sign indicating number of virus shelves in the field; so this is a condition code in order to the machine sign indicating number that starts virus shelves, and [HKLM SOFTWARE Microsoft Windows CurrentVersion RunOnce] be deposit position.

Whether have in dangerous 203 steps of potential virus at the computer that above-mentioned inspection is connected with removable formula Storage Media, its test mode one of can comprise what follows or wherein the two or three or all be equipped with wherein, but be not limited to following manner, in present embodiment, following manner comprises for carrying out in regular turn:

1. check whether wire net of computer: because computer 20 is if fail wire net, then no matter expression is that the renewal of computer 20 operating systems or the renewal of antivirus software, startup etc. all can't normal operations, so whether normally the present invention promptly is by checking the computer 20 be connected with removable formula Storage Media wire net, as judging whether this computer 20 has the foundation of potential virus danger, if computer 20 is wire net normally, represent no potential virus danger, otherwise potential virus danger is then arranged.As for checking the whether mode of wire net of computer 20, one preferable way is to utilize computer 20 operating systems to offer program compilation person to write application code interface (the Application Programming Interface that program reading operation system state is used, be called for short API), read check computer 20 whether the data field of wire net confirmed.

2. check whether computer operating system is updated to last state: because the more new data of its operating system promptly can be disengaged at set intervals in computer 20 operating system manufacturers, security breaches with the repairing work system, with the windows workspace system is example, The built-in has automatically updating function, can be at any time and the servomechanism line of Microsoft, acquisition is also upgraded up-to-date more new data, so the present invention promptly is by checking that the windows workspace system provides the data field of relevant operating system update mode, as judging whether the computer 20 that is connected with removable formula Storage Media has the foundation of potential virus danger, if operating system has been updated to last state, represent no potential virus danger, otherwise potential virus danger is then arranged.As for checking whether computer 20 operating systems are updated to the mode of last state, one preferable way is to utilize computer 20 operating systems to offer program compilation person to write the API that program reading operation system state is used, and reads and checks that the data field whether computer 20 operating systems are updated to last state is confirmed.

3. whether the antivirus software of checking computer starts: the present invention can be by checking that the windows workspace system provides the data field that closes gas defence software startup state, as judging whether the computer 20 that is connected with removable formula Storage Media has the foundation of potential virus danger, if antivirus software starts, represent no potential virus danger, otherwise potential virus danger is then arranged.As for the mode of checking whether computer 20 antivirus softwares start, one preferable way is to utilize computer 20 operating systems to offer program compilation person to write the API that program reading operation system state is used, and reads and checks that the data field whether computer 20 antivirus softwares start is confirmed.

4. whether logfile contains virus signature in the inspection computer operating system: when the present invention proceeds to computer 20 that this inspection is connected with removable formula Storage Media whether dangerous 202 steps of potential virus are arranged, system is according to the stored virus behavior data of this virus behavior database, and seek in the setting shelves of computer 20 operating systems that arrive whether the project that meets the virus behavior data is arranged, expression has potential virus danger if having then, otherwise does not then have potential virus danger.Set the mode whether shelves contain virus signature in computer 20 operating systems as for checking, can utilize computer 20 operating systems to offer program compilation person and write the API that program reading operation system state is used, read in computer 20 operating systems data field of setting shelves and confirmed, or directly open the setting shelves of operating system and directly therefrom check and confirm.

In write command 205 steps of above-mentioned reception to removable formula Storage Media, this write command comprises that desire writes the write command of removable formula Storage Media or the write command that desire is deleted data in the removable formula Storage Media with data, if desire writes data the write command of removable formula Storage Media, then wherein still comprise the file name of desiring to write removable formula Storage Media, in the actual state, the file name of desiring to write removable formula Storage Media is file full name normally, and this document full name has promptly comprised main file name and secondary shelves name; If desire is deleted the write command of data in the removable formula Storage Media, then wherein still comprise and desire the deleted data title, may be file full name, secondary shelves name or directory path.

Allow data are write in removable formula Storage Media 206 steps above-mentioned judging whether, the file name that comparison desires to write removable formula Storage Media forbids writing that tables of data is stored forbids writing file name and whether conform to this; In present embodiment, comparison desires to write the secondary shelves name of file full name of removable formula Storage Media in the write command, whether the stored secondary shelves name that writes removable formula Storage Media of forbidding conforms in the tables of data with forbidding writing, if do not conform to, then carry out this write command of above-mentioned permission data are write removable formula Storage Media 207 steps, otherwise then carry out above-mentionedly not allowing this write command that data are write removable formula Storage Media 208 steps.

Allow to delete in data 209 steps of removable formula Storage Media above-mentioned judging whether, the data name of comparison desire deletion forbids with this whether the stored deleted data title of forbidding of deleted data table conforms to, if conform to, then carry out above-mentioned data 211 steps that do not allow to delete removable formula Storage Media, and must not delete the data that meet this deleted data title in this removable formula Storage Media, otherwise then carry out data 210 steps that removable formula Storage Media is deleted in above-mentioned permission, to delete the data that meet this deleted data title in this removable formula Storage Media.

From the above, use the removable formula Storage Media (for example carry-on dish of USB) of method of the present invention can be when it connects a computer 20, if this computer 20 has potential virus danger, then only allow do not forbidding that writing the listed file that writes file name of forbidding of tables of data writes removable formula Storage Media, or only allow do not forbidding the listed data of forbidding the deleted data title of deleted data table in this removable formula Storage Media of deletion, thus, the user still can forbid writing the listed file that writes file name of forbidding of tables of data and writes removable formula Storage Media being different from, or deletes to be different from this removable formula Storage Media and forbid the listed data of forbidding the deleted data title of deleted data table; If method of the present invention is applied on the computer 20, then it can prevent from its virus that has infected is write in the removable formula Storage Media that computer 20 connects therewith, but still keep to such an extent that will be different from and forbid writing the ability that the listed file of forbidding writing file name of tables of data writes removable formula Storage Media, or can prevent to delete data in the removable formula Storage Media that computer therewith 20 connects, but still keep to such an extent that be different from the listed ability of forbidding the data of deleted data title of deleted data table of forbidding in this removable formula Storage Media of deletion.Be with, method of the present invention can be avoided removable formula Storage Media infective virus or lost data effectively still writing under the prerequisite of data removable formula Storage Media.

The above description of this invention is illustrative, and nonrestrictive, and those skilled in the art is understood, and can carry out many modifications, variation or equivalence to it within spirit that claim limits and scope, but they will fall within the scope of protection of the present invention all.

Claims (29)

1. A read-only protection method for a removable storage medium, comprising the following steps: Establishing a write-prohibited data table, the write-prohibited data table is used to store file names that are prohibited from being written into a removable storage medium; receiving a write command to the removable storage medium, where the write command includes the name of the file to be written into the removable storage medium; Judging whether data is allowed to be written into the removable storage medium is to compare whether the name of the file to be written into the removable storage medium matches the name of the write-prohibited file stored in the write-prohibited data table; If the name of the file to be written into the removable storage medium does not match the name of the write-prohibited file stored in the write-prohibited data table, then the write command is allowed to write data into the removable storage medium, otherwise not The write command is allowed to write data to the removable storage medium. 2. The read-only protection method of the removable storage medium as claimed in claim 1, characterized in that, after setting up a write-inhibited data table, further perform the following steps: Check the computer connected to the removable storage media for potential viruses; If the computer connected to the removable storage medium has no potential virus danger, then the reading and writing of the removable storage medium is completely allowed, otherwise, the write command to the removable storage medium is received, and it is judged whether to allow the reading and writing of the removable storage medium Data is written to a removable storage medium. 3. The read-only protection method of the removable storage medium as claimed in claim 2, characterized in that, whether the computer connected to the removable storage medium is normally connected to the network is used to determine whether the computer has a latent virus risk If the computer can connect to the network normally, it means that there is no potential virus danger, otherwise, there is potential virus danger. 4. The read-only protection method for removable storage media as claimed in claim 2, wherein whether the operating system of the computer connected to the removable storage medium is updated to the latest state is used as whether the computer has potential The basis of virus risk, if the operating system has been updated to the latest state, it means that there is no potential virus risk, otherwise, there is potential virus risk. 5. The read-only protection method of the removable storage medium as claimed in claim 3, further, whether the operating system of the computer connected to the removable storage medium is updated to the latest state, as whether the computer has The basis of potential virus danger, if the operating system has been updated to the latest state, it means that there is no potential virus danger, otherwise, there is potential virus danger. 6. The read-only protection method of the removable storage medium as claimed in claim 2, wherein whether the anti-virus software on the computer connected to the removable storage medium is activated is used to check whether the computer has a potential virus risk If the anti-virus software is activated, it means that there is no potential virus danger, otherwise, there is potential virus danger. 7. The read-only protection method of the removable storage medium as claimed in claim 3, characterized in that, whether the anti-virus software on the computer connected to the removable storage medium is activated as a check and removable storage medium The basis for whether the computer connected to the media has a potential virus risk. If the anti-virus software is activated, it means that there is no potential virus risk, otherwise, there is a potential virus risk. 8. The read-only protection method of the removable storage medium as claimed in claim 4, characterized in that further, whether the anti-virus software on the computer connected to the removable storage medium is started is used as a check and removable storage medium. The basis for whether the computer connected to the media has a potential virus risk. If the anti-virus software is activated, it means that there is no potential virus risk, otherwise, there is a potential virus risk. 9. The read-only protection method for removable storage media as claimed in claim 2, wherein a virus behavior data table is further established, wherein: The virus behavior data table is for storing virus behavior data, which records the signature codes and storage locations that may exist in the configuration file in the computer operating system when the computer is infected with a virus; When checking whether a computer connected to a removable storage medium has a potential virus risk, it is based on whether there is an item in the configuration file of the computer operating system that matches the virus behavior data. If there is, it means that there is a potential virus risk, and vice versa There is no potential virus hazard. 10. The read-only protection method for removable storage media as claimed in claim 3, wherein a virus behavior data table is further established, wherein: The virus behavior data table is for storing virus behavior data, which records the signature codes and storage locations that may exist in the configuration file in the computer operating system when the computer is infected with a virus; When checking whether a computer connected to a removable storage medium has a potential virus risk, it is further based on whether there is an item in the configuration file of the computer operating system that matches the virus behavior data. If there is, it means that there is a potential virus risk. Otherwise, there is no potential virus danger. 11. The read-only protection method for removable storage media as claimed in claim 4, wherein a virus behavior data table is further established, wherein: The virus behavior data table is for storing virus behavior data, which records the signature codes and storage locations that may exist in the configuration file in the computer operating system when the computer is infected with a virus; When checking whether a computer connected to a removable storage medium has a potential virus risk, it is further based on whether there is an item in the configuration file of the computer operating system that matches the virus behavior data. If there is, it means that there is a potential virus risk. Otherwise, there is no potential virus danger. 12. The read-only protection method for removable storage media as claimed in claim 5, wherein a virus behavior data table is further established, wherein: The virus behavior data table is for storing virus behavior data, which records the signature codes and storage locations that may exist in the configuration file in the computer operating system when the computer is infected with a virus; When checking whether a computer connected to a removable storage medium has a potential virus risk, it is further based on whether there is an item in the configuration file of the computer operating system that matches the virus behavior data. If there is, it means that there is a potential virus risk. Otherwise, there is no potential virus danger. 13. The read-only protection method for removable storage media according to any one of claims 2 to 12, characterized in that, through the application code interface provided by the computer operating system, the read check and removable The computer to which the storage media is connected is free of data required for potential virus hazards. 14. The read-only protection method for a removable storage medium according to any one of claims 9 to 12, wherein the setting file of the computer operating system is directly checked by directly opening the configuration file of the operating system Whether there are items in the final file that match the virus behavior data. 15. The read-only protection method for a removable storage medium according to any one of claims 1 to 12, wherein the write-prohibited file name includes a full file name of a main file name and an auxiliary file name. 16. The read-only protection method for a removable storage medium as claimed in claim 13, wherein the write-prohibited file name includes a full file name of a primary file name and a secondary file name. 17. The read-only protection method for a removable storage medium as claimed in claim 14, wherein the write-prohibited file name includes a full file name of a main file name and an auxiliary file name. 18. The read-only protection method for a removable storage medium according to any one of claims 1 to 12, wherein the name of the write-prohibited file is an extension. 19. The read-only protection method for a removable storage medium as claimed in claim 13, wherein the name of the write-prohibited file is an extension name. 20. The read-only protection method for a removable storage medium as claimed in claim 14, wherein the name of the write-prohibited file is an extension name. 21. The read-only protection method for removable storage media as described in any one of claims 1 to 12, wherein a deletion-prohibited data table is further set up, and the deleted-prohibited data table is for storing the name of the deleted-prohibited data, The write command further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in . 22. The read-only protection method of removable storage media as claimed in claim 13, characterized in that, further set up a delete-prohibited data table, which is to store the name of the prohibited-delete data, and the write command and It further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in . 23. The method for read-only protection of removable storage media as claimed in claim 14, wherein a deletion-prohibited data table is further set up, and the deleted-prohibited data table is used to store the names of the prohibited-deleted data, and the write command and It further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in . 24. The method for read-only protection of removable storage media as claimed in claim 15, wherein a delete-prohibited data table is further set up, the delete-prohibited data table is for storing the name of the prohibited-delete data, and the write command and It further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in . 25. The read-only protection method of the removable storage medium as claimed in claim 16, characterized in that, further set up a delete-prohibited data table, the delete-prohibited data table is to store the name of the prohibited-delete data, and the write command and It further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in . 26. The read-only protection method of the removable storage medium as claimed in claim 17, characterized in that, further set up a delete-prohibited data table, which is to store the name of the prohibited-delete data, and the write command and It further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in . 27. The read-only protection method of the removable storage medium as claimed in claim 18, characterized in that, further set up a delete-prohibited data table, which is to store the name of the prohibited-delete data, and the write command and It further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in . 28. The method for read-only protection of removable storage media as claimed in claim 19, wherein a deletion-prohibited data table is further established, and the deleted-prohibited data table is used to store the name of the prohibited-deletion data, and the write command and It further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in . 29. The read-only protection method of removable storage medium as claimed in claim 20, it is characterized in that, further set up a prohibition deletion data table, this prohibition deletion data table is to store the prohibition deletion data name, and this write command and It further includes the name of the data to be deleted, and after receiving the write command to the removable storage medium, further includes the following steps: To determine whether the data on the removable storage medium is allowed to be deleted is to compare whether the name of the data to be deleted matches the name of the data that is prohibited from being deleted stored in the data table that is prohibited from being deleted; If the name of the deleted data does not match the name of the forbidden data stored in the forbidden deletion data table, then the data in the removable storage medium that matches the name of the deleted data is allowed to be deleted; otherwise, the removable storage medium is not allowed to be deleted Data that matches the name of the deleted data in .

Images