(2) background technology
Along with the popularization of project of government's surfing the net, E-Government and government's online working and deeply, the content of increasing government is transferred on computer and the network from traditional paper.The system that relates to state secret information has just become the concerning security matters system, and the network that relates to state secret information has become the concerning security matters network.In order to guarantee the confidentiality of concerning security matters system and concerning security matters network, statutory regulation concerning security matters system and concerning security matters network must carry out physical isolation with other network.
The most crucial problem of information security, computer security and network security is exactly a privacy concerns.Promptly protect computer, information system and network, prevent from not expect the information leakage that takes place.Especially the secret information of government.Privacy concerns is not only the secret information of government, enterprise's business secret, and individual privacy, intellectual property etc. all relate to privacy concerns.Do not wish to take place information leakage, all belong to the category of confidentiality.
A kind of way of maintaining secrecy is that this content of maintaining secrecy is stashed, and other people can't find and obtain the information that will maintain secrecy.Concrete measure is, concerning security matters network and concerning security matters system physical are isolated, and other networks such as inaccurate and the Internet are directly or indirectly networked.When needs are imported data to the concerning security matters system, by portability move medias such as floppy disk, USB, portable hard drives, arrive first in the non-concerning security matters system copies data to move media, then move media is taken away from non-concerning security matters system, manually carry and be inserted in the concerning security matters system, again data are copied in the concerning security matters system.
The greatest problem of this method is, the action of artificial plug can not automation, and exchanges data efficient is low.Simultaneously, also not exclusively possible.In a single day move media inserts the concerning security matters system, and the concerning security matters medium has also become the concerning security matters medium, can not be again uses in non-concerning security matters system.How many move medias a large amount of transferring datas needs, and how these media are managed all is problem.
More complicated way is a gateway, and a kind of Network Isolation and information of manually copying the realization of dish mechanism simulated is changed system.Gateway adopted isolation framework, agreement peel off, use peel off, reduction of data, credible exchange, authentication, Content inspection and filtration, technology such as digital signature have undoubtedly than higher fail safe, if but have the two-way exchange of data, just can not get rid of the possibility of divulging a secret theoretically.
Another method is that data are carried out one-way transmission.Promptly can only transmit data to classified network from non-classified network, can not be from classified network to non-classified network transmission data.There is a problem in one-way transmission in theory, and promptly transmit leg does not know whether reciever successfully accepts data, owing to can not confirm that theoretically, one-way transmission is unreliable, does not have availability.
In order to solve the availability issue of one-way transmission, the method for a lot of compromises has appearred, as little channel feedback (4bit or lbit), channel feedback independently, hardware channel feedback etc.In theory, as long as feedback is arranged, just there is the channel of diving.The size of latent channel, the extent of injury has difference, does not also all have thoroughly to get rid of the possibility of reveal information.
Need a kind of one-way transmission method of not having feedback, both guaranteed physical isolation, also have availability simultaneously, can be in real time from non-concerning security matters system to concerning security matters system transmissions data, simultaneously can not be from the concerning security matters system to non-concerning security matters system transmissions data.Consider secret generality, the low-cost implementation method on existing infrastructure is significant.There was not the research of this respect in the past.
The physical isolation method of no-feedback one-way transmission produces under such technical background.
(5) embodiment
Fig. 1 describes a kind of flow chart of physical isolation method of one-way transmission.Unidirectional transmission system comprises a transmission main frame, and one-way transmission parts are accepted main frame for one.
(1) sends main frame
Sending main frame can be any common computer.As PC, industrial computer, work station, server etc.Sending main frame also can be the processor of special purpose.As embedded computer, digital signal processing appts, microcontroller etc.Any computer comprises input/output port, and wherein output port is the ether medium, can.
(2) one-way transmission parts
The one-way transmission parts are passive circuit and two ether RJ45 interfaces of a special use.RJ45 indicates "+" machine and "-" symbol.Permit data and transmit data to "-" direction from "+", but from physically just not transmitting data to "+" direction from "-".
Fig. 2 has described the circuit diagram of one-way transmission parts.
(3) receive main frame
Receiving main frame can be any common computer.As PC, industrial computer, work station, server etc.Receiving main frame also can be the processor of special purpose.As embedded computer, digital signal processing appts, microcontroller etc.Any computer comprises input/output port, and wherein input port is the ether medium, can.
Receiving computer can not send data to sending computer, therefore, is physical isolation truly.
Receiving computer also comprises an alarm appliance.Can directly get final product with the loudspeaker on the PC.Also can connect a display, error message is directly printed on the screen.Also error message can be write on the storage medium.
(4) method of work
Fig. 3 has described a kind of flow chart of one-way data transmission method.
4.1 transmission synchronizing information
The first step of the method that Fig. 3 describes is to send synchronizing information.
Because the one-way transmission and the physical isolation characteristic of one-way transmission parts receive main frame and can't send information to sending main frame, therefore send main frame and know the state that receives main frame never.The computer of present main flow all is the interrupt requests working method that adopts, and is in busy operating state if receive main frame, and this is to send main frame to send data, and the reception main frame just may be handled and not come over, thereby produces mistake or obliterated data.
The present invention provides a kind of method for synchronous.It is the transmit leg of synchronizing information that this method for synchronous regulation sends main frame, sends main frame and formulates synchronizing information according to the task of transmission situation.
Synchronizing information of the present invention, regulation regularly sends synchronizing information according to certain Fixed Time Interval.
4.2 receiving synchronous information
Second step of the method that Fig. 3 describes is a receiving synchronous information.
It is the recipient of synchronizing information that a kind of method for synchronous that the present invention provides, regulation receive main frame, receives main frame and receives unconditional following after the synchronizing information.
Receive main frame after losing synchronizing information, the system that unconditionally guarantees immediately receiving synchronous information is not received any interference, promptly has the highest priority.
4.3 carry out the redundant correcting coding to sending data
The 3rd step of the method that Fig. 3 describes is that data to be sent are carried out the redundant correcting coding.
One-way transmission does not have reliability to guarantee theoretically, and the meeting obliterated data can be introduced mistake, does not therefore possess availability.
The present invention can obliterated data be a prerequisite with one-way transmission, introduces one group of redundant correcting encryption algorithm.Fig. 4 has described the flow chart of this algorithm.This algorithm, at first data are carried out piecemeal, every size is consistent, and chooses the N blocks of data and forms one group, every group of data are carried out parity check (B), choose N group data, from every group of data, choose one in order, form one again sequentially and newly organize, it also is the N group, each data of new group is being carried out parity check (P), and the parity data combination with twice produces data to be sent.
The redundant correcting algorithm is realized redundant characteristic by twice parity check, has very high error correcting capability.
4.4 transmission data
The 4th step of the method that Fig. 3 describes is to send data.
What send the main frame transmission is through the redundant correcting coded data.Router itself also carries out error checking to sending data, and data may comprise parity bit (parity bit), check code (checksum), error detection code (error detection code) and error correcting code (error correctioncode) etc.But this undercapacity can not replace the 4.3 redundant correcting encryption algorithms of carrying can guarantee the correctness of data.
Router is signed to sending data, sends to the reception main frame.
After data send, because can not send data to the transmission main frame from receiving main frame on the system physical, because do not receive the function of affirmation.No matter mistake can or can not occur, remaining work is given the redundant correcting decoding algorithm and is gone to finish.
4.5 reception data
The 5th step of the method that Fig. 3 describes is to receive data.
After the reception main frame is received data, confirm whether signature is correct,, be considered as attacking, abandon data if incorrect.
Data after signature is correct, reception program itself is also carried out error checking to receiving data, and data may comprise parity bit (parity bit), check code (checksum), error detection code (error detection code) and error correcting code (error correction code) etc.But this undercapacity can not replace the 4.6 redundant correcting decoding algorithms of carrying can guarantee the correctness of data.
4.6 carry out the redundant correcting decoding to receiving data
The 6th step of the method that Fig. 3 describes is to receiving that data carry out the redundant correcting decoding.
After the data that the reception program is received, carry out the redundant correcting decoding, the reduction initial data.
The present invention can obliterated data be a prerequisite with one-way transmission, introduces one group of redundant correcting decoding algorithm.Decoding algorithm is the reverse process that Fig. 4 has described encryption algorithm.The redundant correcting algorithm is realized redundant characteristic by twice parity check, has very high error correcting capability.
4.7 discovery mistake
The 7th step of the method that Fig. 3 describes is to find mistake.
Although the present invention has very strong redundant correcting ability, under many circumstances, data send mistake may occur, as ageing equipment, equipment fault, power failure or environmental interference etc., in this case, bust this.Data transmission fails need clearly be found data transmission fails, avoids system to be in nondeterministic statement.
Find mistake, mainly comprise the redundant correcting decoding find data be wrong be bust this, the reception program finds that receiving data itself imperfect is bust this, the reception program is overtime in a synchronous regime to be bust this etc.
4.8 false alarm
The 8th step of the method that Fig. 3 describes is an error message warning.
After finding mistake, carry out false alarm.
The mode of false alarm comprises, mistake is write daily record, prints on the screen or by receiving the forms such as audible alarm of main frame.
4.9 storage data
The 9th step of the method that Fig. 3 describes is the storage data.
When not finding mistake,, be stored in the storage medium of appointment to the data of correct reception.
4.10 other specific implementation
Except the mode of Fig. 1, consider the consideration of aspects such as electromagnetic radiation leakage, a kind of specific implementation way of the present invention is placed on two main frames and one-way transmission parts within the cabinet, promptly comprises two computer motherboards and one-way transmission parts in a cabinet.Also can be grafted directly to the one-way transmission parts on the ether medium or the line preface of ether line on.
Under the situation that does not break away from spirit of the present invention and fundamental characteristics, the present invention may have the multiple form of expression, unless so should be appreciated that certain illustrated, the above embodiments are not limited by previously described any details, explain widely but be construed as within the defined such spirit and scope of claim.Therefore corrigendum and the modification within the claim scope, and other equivalence transformation within this scope is also included among the claim.