ATM security survey

Estimated ATM will be may very many different applications (for example: The sound, the image, the data and so on) all concentrate in the network, and has the high speed directional connection company net standard which the different grade of service (QoS) requests. Entrusts with 640-863 ATM as the directional connection the characteristic to indicate that, the connection uses the fixed route the entire network and on the constitution route 640-863 link retention band width all is for satisfy QoS the application request. In order to assigns the source destination antithesis pitch point establishment connection, must choose the good entire network the route. In the ATM network 640-863 route since establishes (namely incompletely is in advance permanent connection) also is in under the dynamic situation request immediately according to the connection request establishment. In is called in the ATM letter Yuan short fixed 640-863 length grouping package to carry very many different types the information. The ATM letter 元长度 is composed by 53 bytes, 48 bytes are the actual loads, other 5 bytes constitution letter Yuan first. Is all included within in the edge network user information frame the ATM letter Yuan. Assigns (goal) in the network the side, the user information frame all is by the letter Yuan which turns on reconstitutes.

ATM at present displays one 640-863 of weakness is it does not provide the safe service, this when implements the ATM ability for the customer is a main barrier. Although the more and more business organization, the financial field and the government department all in abundance request to change ATM, but in order to fully displays ATM the potential, people all urgent need ATM should have the safe service. At present the overwhelming majority ATM electric circuit all only can (PVC) exist by the permanent empty 640-863 electric circuit, and by special line connection fixed company's locus. But, when it arrives stretches across the common boundary the exchange empty electric circuit (SVC) or stretches across the service provider network company interior SVC, the ATM effective use value becomes had decided whether promotes uses ATM the primary factor.

ATM will possibly be able to use in the future to the mission requirement extremely strict communication 640-863 application domain, will like the financial transaction, the medical service information system, the national defense military correspondence and so on. These applications all request in the safe correspondence to have the high reliable crypto-algorithm and the agreement make the guarantee. Said on the very strong ATM safety mechanism that, to guards against the deceit, guards against malicious the data revision as well as guards against the interception and so on all to have to have the practical reliable guarantee measure. If in these mechanism guarantees situations, the important task application only has not been able to depend on the 640-863 expensive expenditure to be able to exist, perhaps this all is because does not have the equipment which may mutually operate therefore.

Security ATM must provide most is low grade is the ATM vertex distinction as well as the protection user data measure. The ATM high speed letter Yuan relaying performance in guaranteed in its safe duty to display some special questions. Some questions may outline as follows:

1) the safe service must adapt in effective ATM letter Yuan Ji 细粒度 multiplex, requests the key to be supposed to have the corresponding flexibility, also is must use the different key to the different data pool letter Yuan.

2) because the ATM network high speed and the strict grade of service (QoS) requests, the safe service should not bring the attachment the detention or the letter Yuan detention change.

3) the high speed transmission speed causes the conversation to save the current account the key only to have a very short cycle. Therefore, the traditional entire key swap agreement is not 640-863 suitable, moreover in order to can renew these keys to need frequently to carry on the revision to these keys. In other words, requests in a longer time foundation reto revise the key also to have to have the new mechanism.

4) the password mechanism must have in the flexible in the key situation, by 1Gbps speed operation. At present, the well known password mechanism possibly very is difficult to adapt these 640-863 requests.

5) the password mechanism also must carry on under the different speed mutually operates. For example: May (SONET) OC - the 3C company arrive a client after the synchronized optical fiber network in the ATM network, but its server may have OC - 48C the connection. Obviously, the server encryption installment (may be a parallel realization algorithm) must (be allowed to be a serial realization similar algorithm) carries on with the client encryption installment mutually operates.



The ATM security defines which by the 640-863 ATM topic security work team is imitates the ATM agreement reference model to draw up. This agreement reference model by the division is three 640-863 planes: User plane, control plane and management plane. The user plane guarantee supplies transmission user's data, it contains the physical level, the ATM level and multi- ATM suitably matches the level (AAL) several kind of types. The control plane needs to process the connection the establishment, the release and other connection functions. Control plane and user plane sharing physics level and ATM level. Moreover, it also includes according to AAL5 and a higher letter the 640-863 letter which was stipulated the agreement makes AAL. The management plane execution management harmonious cooperation adjusts the user and the control plane both sides related function. The ATM topic security specifications is must provide the user in the first stage the plane (data) the safe service and the control plane (letter makes) the safe service standard. Perhaps to will manage the plane the safe service to have in the future standard issue time only then will be able to provide.

ATM user plane safe service
The user plane safe service is must the load bearing user information provide the protection to very many 640-863 ways in the empty connection. The distinction is must cause the call origination and obtain by call origination each other the absolute confirmation, and causes the third party not to have to pretend one of its two.

The key exchange service is must cause the call origination and the key which obtain by the call origination is consistent, this key is uses in empty connection survival period provides the data integrity and the secret service. The complete service is must provide by the empty connection load bearing data cannot the guarantee which is revised by the third party. The secret service is must provide prevented transmits the data in the empty connection not the third party "the interception" the protection. Finally, the access control service is must provide other correlation security information the protection, namely establishes in the connection, must enable the terminal to determine whether defers to the scene the security policy to accept the connection the request.

The user plane safe service which will define by the ATM topic group can apply to the spot to and to the multi- spots connection empty channel connection (VCC) and the empty circuit connection (VPC). Said to the first stage security specifications that, is making the stipulation to three kind of situations safe services, namely: User to user, user to network and network to network. Every is can realize the security ATM pitch point all has "the security proxy" the function, this security proxy may carry out when the connection establishment and connection survival period plays the role security agreement and the safety mechanism.

Distinction, key exchange and security option consultation

The distinction is the user plane safe service, it may cause the connection to establish the entire process bilateral each other to obtain the absolute confirmation. This not only has the very vital role to its direct benefit, moreover because to other safe services, like the key exchange also is the need. The distinction, the key exchange and the security option consultation must give in here to narrate together, because must realize these three characteristics to need to use the similar agreement.

Does not like directional data newspaper agreement such, they only have in each grouping package of foundation complete the distinction, but the ATM directional connection characteristic may cause in the connection establishment period two parts both to use the more precise distinction agreement, because is connected with the digital signature the total expenses cost must repay in the entire connection lifetime, therefore in connection establishment period may use strongly (even if is slower) distinguishes the agreement. This also may cause other security functions (to like key exchange) at the same time then to complete by the small amount attachment expenses.

Considered the above this kind of characteristic, the ATM topic work team had stipulated when establishes VCC or VPC uses the agreement, this agreement may complete the distinction, the key exchange and the security option consultation. This agreement mainly is ISO/IEC which (ISO) the international electronic committee (IEC) draws up according to the International Standardization Organization 9,594 - 8 and the ISO/IEC 11,770 - 2 standards is the basis, it provided has used three flows or two flows does mutually distinguishes. Two and three users planes security text of a telegram swap agreement certainly did not decide uses what kind of specific crypto-algorithm. Said to each method that, the distinction all may use is asymmetrical or the symmetrical crypto-algorithm completes.



Security text of a telegram swap agreement

In two and three securities text of a telegram swap agreement, an agreement side user is shouldering "the starting" the role, another side user is getting up "the response" role. On behalf of the starting user operation "the security proxy" thought is "the starting", on behalf of the response user operation thought is "the response".

In security text of a telegram swap agreement, when uses the asymmetry (publicly) the key algorithm, may suppose each distinction entity (namely A, B) has a public key/private dense key to be right. When uses in the encryption, Ka expresses the A asymmetrical key public part. When to digital signature, Ka expresses the A asymmetrical key special-purpose part. Is similar to the B entity situation. When uses (secret) symmetrically the key algorithm, then must suppose the distinction entity A and B altogether uses two unidirectional secret keys Ka and Kb or sole secret key Ka=Kb.

The safe consultation is completes through the operating parameter in three swap agreements. In order to support in the system structure the flexibility to need to carry on the consultation. This flexibility needs to permit the performer and the user may choose the crypto-algorithm and they likes with the agreement. In the first flow, the starting provides a safe service table of contents and the connection use parameter (for example: Algorithm type, key length, public key concrete algorithm parameter). In the second flow, the response must act according to serves the table of contents and the connection parameter replied. If the starting is consistent with the response, that has carried out the agreement, moreover both sides have both used the parameter which the service and the response reply contained, otherwise, this agreement and the connection request crashed.

Agreement adjustment

When designated when ATM two or three securities texts of a telegram transmit the agreement, must consider has the many kinds of adjustments measure existence. These adjustment measure as follows are going to carry on the narration to it, its outline see Table 1 (n is in network pitch point number, safety clothing must carry on application to them). In order to protect the distinction agreement is far away uses "the replay attack" well known the deceit, the distinction flow must be only, has the foreword moreover is newest. Regarding this may some two ways achieve that, Uses the time stamp obliging serial number or "the inquiry responds" the agreement by way of.

If requests in two flows mutually to distinguish or requests in a flow to the source to send the side to carry on the distinction, then should use based on the time stamp way. Sends the side according to the source the distinction certificate, if uses ATM "the firewall" to come passively to filter out (with end system related) connects the request, then latter is important. But, is sends the side and between the certificate distinction certificate entity based on the time stamp way disadvantage factor in the text of a telegram source the request has the certain degree time synchronization.

Through uses a time of random number or is near 时数, it "the inquiry responded" the way to provide has been unitary, the arrangement has the foreword and the most new style essential guarantee. This must through transmit "the inquiry" to realize near 时数 the achievement, namely is solid to the long-distance distance essentially to 计数法 marks and returns to the entity which must inquire.

Moreover, the coordination also relates uses (public key) the algorithm resistance to be symmetrical asymmetrically (secret key) the algorithm question. The asymmetrical algorithm provides each entity all has by this entity maintenance "the private dense key", but the public key, it may freely proliferate, moreover may use by other people confirmed by belongs to the digital signature which the entity the key produces is effective. The asymmetrical algorithm (and encrypts this two to digital signature to say) the merit is, the private dense key only requests each user to appear a time, this causes the key management to change complex, but, asymmetrical algorithm because uses the complex function, the picture "the modulus takes the power", therefore it very is precise in the computation.

In on the other hand, the symmetrical algorithm may very quickly carry on the computation, because they have specially utilized "shifting and the arrangement" the operation. But, the symmetrical algorithm wants the as desired source to send with the destination solid essential sharing identical public key. Has several pitch points to the networks, has two and three swap agreement each other distinction ability requests each pitch point with to possess other pitch points all to have to have the common key, like this may by O (n2) express the key manages complexity. In the large-scale network, the key management complexity needs to act according to the symmetrical algorithm to carry on the distinction.


ATM safely transmits
In order to complete the above safe service, needs to have the correlation the security text of a telegram transmission mechanism, uses through the safe service change transmits the mechanism to be decided thereupon when connection establishment or in the connection lifetime requests the service. When connection establishment, the security text of a telegram may the data channel which or reestablishes make the channel carry on after the letter the exchange. In connection survival period, the OAM letter Yuan uses for the load bearing security text of a telegram.

Transmits in the connection establishment time security
To connects establishes said that, some two methods use in safely to transmit. If all supports in the end system letter make the entity and the network equipment safely transmits, then the security text of a telegram may makes in the channel in the letter to exchange. But, if these equipment do not support the security text of a telegram, then carries the system and the security proxy all must after the connection establishment, transmits in front of the data on new VCC/VPC, exchanges the security text of a telegram in the data channel.

The connection lifetime security transmits
Once the data connection can establish, related exchange security text of a telegram mechanism on request password synchronization and execution conversation key renewal. Because these texts of a telegram all are with the data business volume related sensitive time, they must take the attachment the data transmits in same VCC/VPC. Moreover, if again the synchronized text of a telegram possibly arrives too late, thus has been separated from synchronized decipher processing.

The security work team accepts the way is uses load bearing correlation security information the OAM letter Yuan. This kind of OAM letter Yuan already may be F4 (the VPC level), also may be F5 (the VCC level) OAM letter Yuan, moreover likes like this can very quickly the end system or the security proxy which receives distinguishes. In these two kind of situations, its OAM letter Yuan type is "the system administration", in order to indicate the security function only then stipulated has "the function type" suitably.

Subtotal
ATM safely besides provides the network infrastructure the related protection, but also can provide the user information the protection. The ATM security is after the ATM agreement reference model imitates draws up, it divides three planes are: The user plane, the control plane and manage evenly. The first stage ATM topic security specifications has mainly arranged the user plane safe service and the control plane limited service.

The ATM user plane service has stipulated in the empty electric circuit by the massive methods load bearing to the user information protection. The access control service emphasized any may allow the visit to connect ATM the service and the resources. The distinction service had guaranteed is obtained to the call origination and by the call origination the real confirmation. The secret service had stipulated the encryption mechanism, protected the entire ATM connection load bearing after the authorized information, the complete service guarantee has avoided to the user data value revising or the survey user data order. (End)