CN105429965A - Conflict Resolution Method for Negotiating Trust Rules - Google Patents

Abstract

The invention provides a conflict handling method of a negotiation trust rule. The method comprises that a minimal certificate set is established; a certificate set held by a request party matches elements of the minimal certificate set; if a set element which is contained in the certificate set held by the request party is found in the minimal certificate set, negotiation is determined to succeed, and a negotiation party agrees resource access of the request party; and if a set element which is contained in the certificate set held by the request party is found in the minimal certificate set, negotiation is determined to failure, and the negotiation party rejects resource access of the request party.

Description

Conflict Resolution Method for Negotiating Trust Rules

technical field

The present invention relates to the communication field, and more specifically, the present invention relates to a conflict resolution method for negotiating trust rules.

Background technique

In traditional trust negotiation, there is no process of trust rule conflict detection and resolution before the negotiation, and the negotiating parties directly organize the negotiation according to the negotiated trust rules they have formulated. However, if there is a conflict in the trust rules, it is difficult to detect and resolve the conflict during the negotiation process, and organizing the negotiation based on the conflicting trust rules not only wastes the interaction time, but also leads to unnecessary privacy exposure. Therefore, it is very necessary to detect trust rule conflicts before negotiation and resolve the conflicts to a certain extent. Although researchers have done a lot of work on conflict detection, for example, some people have tried to use the 0-1 table to describe trust rules to detect conflicts, but no relevant theoretical basis and in-depth research have been provided. In addition, some people have proposed a linear description and analysis of trust rules, but this is more for theoretical research and is not easy to implement. From the perspective of algorithm implementation, some people proposed to use matrix form to describe trust rules and gave a conflict detection algorithm, but it cannot be flexibly changed and expanded according to the requirements of the application environment.

Generally speaking, none of these existing studies proves the rationality of their conflict detection methods, nor does it provide a method to resolve conflicts.

Contents of the invention

The technical problem to be solved by the present invention is to provide a conflict resolution method for negotiating trust rules in view of the above-mentioned defects in the prior art, which can solve the problem of deadlock conflicts and use the method of rule reduction to disclose the minimum set of certificates at one time method to resolve it.

In order to achieve the above technical purpose, according to the present invention, a conflict resolution method for negotiating trust rules is provided, which is characterized in that it includes:

Step 1: Establish a minimum set of certificates;

The second step: match the certificate set held by the requesting party with the elements of the minimum certificate set;

Step 3: If a set element is found in the minimum certificate set so that it is included in the certificate set held by the requesting party, it is determined that the negotiation is successful, so that the negotiating party agrees to the resource access of the requesting party;

Step 4: If no set element is found in the minimum certificate set so that it is included in the certificate set held by the requesting party, it is determined that the negotiation is unsuccessful, so that the negotiating party refuses the resource access of the requesting party.

Preferably, the minimum set of certificates includes a plurality of elements, wherein each element is a set of certificates that must be disclosed for a corresponding negotiation path of the label tree of the negotiation rule.

Preferably, the tag tree is a simplified tag tree.

Preferably, the simplified rules of the label tree include: if a meta-rule of the negotiation rule is true, traverse the entire label tree, and delete the node corresponding to the meta-rule on the label tree.

Preferably, the simplified rules of the label tree include: if a meta-rule of the negotiation rule is false, all paths from the meta-rule node to the root node of the label tree are eliminated.

Preferably, the simplification rules of the label tree include: if there are repeated nodes on a path to the root node of the label tree, only one of the repeated nodes is kept.

Preferably, the simplification rule of the label tree includes: traversing each path to the root node of the label tree in turn, and if a path identical to other paths is found, the path is eliminated.

Preferably, the simplification rules of the label tree include: if all the nodes of a path to the root node of the label tree are included in another path, then the other path is eliminated.

Preferably, the simplification rules of the label tree include: if a path to the root node and another path of the label tree only contain identical nodes and opposite nodes, one of the paths is deleted, and the opposite node in the other path is deleted.

In the process of trust negotiation, there are often phenomena such as self-contradiction, negotiation deadlock, and negotiation failure. The conflicts in trust rules are the reasons for these problems. Therefore, since the present invention can resolve conflicts of trust rules, it can avoid negotiation failure caused by using conflicting trust rules in the process of trust negotiation, thereby saving negotiation interaction time and avoiding unnecessary privacy exposure . Therefore, the present invention can effectively solve the problem of establishing a trust relationship under the premise of protecting the privacy of all parties.

Description of drawings

A more complete understanding of the invention, and its accompanying advantages and features, will be more readily understood by reference to the following detailed description, taken in conjunction with the accompanying drawings, in which:

Fig. 1 schematically shows an example of label tree description of trust rules.

Fig. 2 schematically shows an example of absorption simplification of a tag tree.

Fig. 3 schematically shows a simplified example of merging tag trees.

Fig. 4 schematically shows a flowchart of a conflict resolution method for negotiating trust rules according to an embodiment of the present invention.

It should be noted that the accompanying drawings are used to illustrate the present invention, but not to limit the present invention. Note that drawings showing structures may not be drawn to scale. And, in the drawings, the same or similar elements are marked with the same or similar symbols.

detailed description

In order to make the content of the present invention clearer and easier to understand, the content of the present invention will be described in detail below in conjunction with specific embodiments and accompanying drawings.

For ease of understanding, the following first introduces the basic grammatical structure of the logical description of trust rules.

The syntax symbols involved in trust rules are:

Proposition variables: s,c ₁ ,c ₂ ,…,c _n , where s represents the corresponding resource, and _ci represents the certificate. Especially sometimes s can also be regarded as a certificate.

Propositional constants: true, false, respectively indicating that the certificate can be disclosed unconditionally or never.

Connectives in the body of the rule: ∧, ∨, Represents a logical AND, OR, and inverse operation between certificate variables.

Left and right brackets: (,).

Dependent operation symbols of resource and rule body: ←, which means that if the certificate requirements of the rule body are met, the dependent operation of the resource is disclosed.

Therefore, the basic grammatical structure of the logical description method of trust rules is as follows: for a resource s, the corresponding trust rules p _s can be expressed as follows: s←f _s (c ₁ ,c ₂ ,…,c _n ), where f _s (c ₁ ,c ₂ ,…,c _n ) is the trust certificate c ₁ ,c ₂ ,…,c _n , Boolean constants true, false, Boolean operators ∧, ∨, and parenthesized expressions. The semantics of ← is: if the negotiating party satisfies the condition f _s (c ₁ ,c ₂ ,…,c _n ), that is, discloses the required certificate, then it is considered that s←f _s (c ₁ ,c ₂ ,…,c _n ) Established, that is, the resource s can be successfully shared.

In addition, if there are two trust rules in the form of C←B and B←A, then according to logical principles, it can be deduced that C←A is established.

Therefore, s←f _s (c ₁ ,c ₂ ,…,c _n ) means that the local trust certificate s can be disclosed if and only if the other party discloses the trust certificate c ₁ ,c ₂ ,…,c _n . In particular, the trust rule s←true means that the trust certificate s does not need to be protected by trust rules and can be unconditionally disclosed to any negotiator. Conversely, the trust rule s←false means that the trust certificate s cannot be disclosed under any circumstances.

There are several truth characterizations of logical propositions of trust rules as follows:

①Eternal truth form (tattoo form): that is, if f _s (c ₁ ,c ₂ ,…,c _n )≡1, then the regular body f _s (c ₁ ,c ₂ ,…,c _n ) is an eternal truth form (tautology);

②Permanent form (contradiction): If f _s (c ₁ ,c ₂ ,…,c _n )≡0, then the rule body f _s (c ₁ ,c ₂ ,…,c _n ) is a perpetual form ( contradictory);

③Contingency formula: when the certificates c ₁ , c ₂ ,…,c _n take different assignments respectively, f _s (c ₁ ,c ₂ ,…,c _n ) may take the value 1 or 0, then Regular body f _s (c ₁ ,c ₂ ,…,c _n ) is a probabilistic formula;

④Satisfiable formula: when there is at least one assignment combination of c ₁ ,c ₂ ,…,c _n making the value of f _s (c ₁ ,c ₂ ,…,c _n ) true, the assignment { _ci = 0 or 1|1≤i≤n} is the solution of the logical expression f _s (c ₁ ,c ₂ ,…,c _n ), and the expression f _s (c ₁ ,c ₂ ,…,c _n ) is satisfiable of.

From the foregoing, we can see that trust rules can be regarded as logical propositions, among which the trust achievement rule is the key proposition, and it forms a logical system with trust intermediate rules. Obviously, in this logical system, the logical properties of trust rules, such as equivalence, coordination, and satisfiability, can be analyzed.

In the process of analyzing the logical nature of trust rules, some principles of logical deduction may be used. It may be assumed that for trust rules s←c _i (1≤i≤n), the deduction criteria for logical operations between them are listed as follows:

(L1):(s←c ₁ )∧(s←c ₂ )＝(s←c ₁ ∧c ₂ )

(L2): (s←c ₁ )∨(s←c ₂ )＝(s←c ₁ ∨c ₂ )

(L3): (s←c ₁ )∨((s←c ₁ )∧(s←c ₂ ))＝(s←c ₁ )

(L4): (s←c ₁ )∨(s←false)＝(s←c ₁ )

(L5): (s←c ₁ )∧(s←true)＝(s←c ₁ )

(L6): (s←c ₁ )∨(s←true)＝s←true

(L7): (s←c ₁ )∧(s←false)＝s←false

(L8): (s←c ₁ )∧(s←c ₂ )=(s←c ₂ )∧(s←c ₁ )

(L9): (s←c ₁ )∨(s←c ₂ )＝(s←c ₂ )∨(s←c ₁ )

(L10): (s←c ₁ )∧((s←c ₂ )∨(s←c ₃ ))＝(s←c ₁ ∧c ₂ )∨(s←c ₁ ∧c ₃ )

(L11): (s←c ₁ )∨((s←c ₂ )∧(s←c ₃ ))＝(s←c ₁ ∨c ₂ )∧(s←c ₁ ∨c ₃ )

(L12):

(L13):

(L14):

<trust rule deadlock violation>

Assume that C _A and C _B represent the certificate sets of resource requester A and resource provider _{B respectively, and PA and P B represent} the trust rule sets of party A and party B respectively. In the negotiation process, the resource or service s∈ C _B 's request starts, if the negotiating parties have the following trust rules, p _ci :ci ←g _ci (s _j ) and p _sj : _{s j} ←h _sj (ci ), where _{ci and s j are negotiating} parties For the certificates held by A and B, p _ci and p _sj are trust rules containing certificates ci and s _j respectively, g _ci (s _j ) represents a logical expression containing certificate _{s j} , h _sj ( _ci ) represents If the logical expression contains the certificate _ci , it is said that there is a deadlock conflict in the trust rules p _ci and p _sj .

In order to facilitate the simplification of the trust rules, this section first expresses the trust rules as a disjunctive paradigm, and then uses the rule label tree (ACP-LTree) to describe as follows:

The root node of each label tree represents the resources to be accessed in the trust rules, and other nodes represent the certificates required to be disclosed in the trust rules. Each non-root node contained in the path from the leaf node to the root node constitutes a set representing the set of attribute certificates that must be disclosed for accessing resources and establishing trust.

For example, the trust rule s←(c ₁ ∧c ₂ )∨(c ₃ ∧c ₄ )∨(c ₃ ∧c ₅ ∧c ₆ )∨(c ₇ ∧c ₈ ) can be expressed as a label as shown in Figure 1 Tree. If you want to access s, you should at least meet the certificate requirements contained in the path from a leaf to the root node in the label tree, that is, the disclosure certificate set {c ₁ ,c ₂ },{c ₃ ,c ₄ },{c ₃ , c ₅ ,c ₆ } or {c ₇ ,c ₈ } to access resource s.

The rules that can be followed to simplify the trust rules represented by the label tree are as follows:

(1) If a meta-rule is true (true, indicating that the certificate can be disclosed unconditionally), traverse the entire tree and delete the node corresponding to this rule on the tree;

(2) If a certain meta-rule is false (false, indicating that it can never be disclosed), then eliminate all paths (including edges) passing through the node to the root node;

(3) If there are duplicate nodes on a path to the root node, only one is kept, and other duplicate nodes are eliminated;

(4) Traverse each path to the root node in turn, if a path identical to it is found, then eliminate the path;

(5) If a path to the root node, its nodes are all included in another path, then eliminate another path, as shown in Figure 2;

(6) If a path to the root node has the same node and the opposite node as another path, one of the paths is eliminated, and the opposite node is deleted from the other path (symbol " ” means node inversion), as shown in Figure 3.

<minimum certificate set>

In trust negotiation, there may be n negotiation paths to achieve successful negotiation, and the negotiation is carried out according to the i-th (1≤i≤n) path. If the resource requester wants to access the target resource of the other party and establish trust, at least the set of certificates that need to be disclosed denoted as {c _i ,…}, then the set composed of {c _i ,…} as elements is called the minimum certificate set, denoted as {{c _i ,…},…}.

When a trust rule is described in the form of a label tree, after it is reduced according to the reduction rule, the non-root node contained in each path from the leaf node to the root node is an element of the minimum certificate set, and all these elements constitutes the minimum set of certificates C _M satisfying this rule.

<conflict resolution>

With the minimum certificate set, the deadlock conflict of trust rules can be resolved by the method of one-time disclosure of the minimum certificate set. During the trust negotiation process, according to the certificate and trust rule matching algorithm, it is detected whether the requesting party holds the certificate required by the minimum certificate set, so as to judge whether the negotiation can be directly successful. The method is as follows:

According to the certificate and trust rule matching algorithm, the requester A uses the certificate set C _A held by itself to match the elements of the minimum certificate set C _M , if and That is, if a set element can be found in _{C M} so that it is included in CA, then the certificate required by the minimum certificate set is disclosed at one time, and the negotiation is successful, and there is no need to disclose other sensitive information through multi-step negotiation steps. Otherwise, the requesting party A does not meet the negotiating requirements of the other party, and the negotiating party rejects the resource access of the requesting party. It can be seen that the negotiation result can be reached through one-time certificate matching. On the one hand, it can improve the negotiation efficiency and success rate, and on the other hand, it can also solve the deadlock problem of certificate circular dependence that may be caused in the process of gradually disclosing certificates.

Correspondingly, FIG. 4 schematically shows a flowchart of a conflict resolution method for negotiating trust rules according to an embodiment of the present invention.

As shown in FIG. 4, the conflict resolution method for negotiating trust rules according to an embodiment of the present invention includes:

The first step S1: establishing a minimum certificate set; wherein the minimum certificate set includes a plurality of elements, wherein each element is a set of certificates that must be disclosed for a corresponding negotiation path of the label tree of the negotiation rule.

The second step S2: matching the certificate set held by the requesting party with the elements of the minimum certificate set;

The third step S3: If a set element is found in the minimum certificate set so that it is included in the certificate set held by the requesting party, it is determined that the negotiation is successful, so that the negotiating party agrees to the resource access of the requesting party;

Fourth step S4: If no set element is found in the minimum certificate set, so that it is included in the certificate set held by the requesting party, it is determined that the negotiation is unsuccessful, so that the negotiating party rejects the resource access of the requesting party.

In the present invention, by disclosing the minimum certificate set at one time, the use of deadlock trust rules in negotiation can be avoided, thereby indirectly resolving deadlock conflicts. Resolving deadlock conflicts in trust rules can avoid negotiation failures caused by using conflicting trust rules in the process of trust negotiation. The proposed conflict resolution method of negotiated trust rules meets the actual needs, and can effectively solve the problem of trust relationship establishment under the premise of protecting the privacy of all parties in automatic trust negotiation. For the open network environment, it has theoretical and practical significance to provide trust guarantee and support resource security sharing.

<Program example of certificate and trust rule matching algorithm>

In order to facilitate those skilled in the art to implement the present invention, a specific example of the certificate and trust rule matching algorithm program "credencialPolicyMatch" is given below.

In addition, it should be noted that, unless otherwise specified or pointed out, the terms “first”, “second”, “third” and other descriptions in the specification are only used to distinguish each component, element, step, etc. in the specification, and It is not used to represent the logical relationship or sequential relationship between various components, elements, and steps.

It can be understood that although the present invention has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or be modified to be equivalent to equivalent changes. Example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention, which do not deviate from the technical solution of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. consult a conflict resolution method of trusting rule, it is characterized in that comprising:

First step: set up minimum certificate collection;

Second step: certificate collection requesting party held mates with the element of minimum certificate collection;

Third step: find a set element if concentrated at minimum certificate, it is included in, and certificate that requesting party holds is concentrated, then judge to consult successfully, thus negotiation the other side agrees to the resource access of requesting party;

4th step: do not find a set element if concentrated at minimum certificate, it is included in, and certificate that requesting party holds is concentrated, then judge to fail to consultations, thus consult the resource access of addressee refuses requesting party.

2. method according to claim 1, is characterized in that, described minimum certificate collection comprises multiple element, and wherein each element is the corresponding set of certificates of consulting path and must disclose of the tag tree for negotiation rules.

3. method according to claim 2, is characterized in that, tag tree is a tag tree through simplifying.

4. method according to claim 3, is characterized in that, the rule of simplification of tag tree comprises: if negotiation rules a meta-rule is true, then travel through whole tag tree, the node that this meta-rule of cancellation is corresponding in tag tree.

5. method according to claim 3, is characterized in that, the rule of simplification of tag tree comprises: if negotiation rules a meta-rule is false, then cancellation is by all paths of meta-rule node to the root node of tag tree.

6. method according to claim 3, is characterized in that, the rule of simplification of tag tree comprises: if one of tag tree to the path of root node there is the node of repetition, then only retain in duplicate node.

7. method according to claim 3, is characterized in that, the rule of simplification of tag tree comprises: the path of every bar to root node traveling through tag tree successively, if find a paths identical with other path, then and this paths of cancellation.

8. method according to claim 3, is characterized in that, the rule of simplification of tag tree comprises: if tag tree node to the path of root node all comprises all in another paths, then another paths described in cancellation.

9. method according to claim 3, it is characterized in that, the rule of simplification of tag tree comprises: if tag tree path to root node and another paths only comprise same node point and opposing node, then a cancellation wherein paths, and leave out the opposing node in another paths.