Abstract: Real-time techniques for determining all access requests to an attribute-based access control policy which evaluate to a given decision, “permit” or “deny”. The policy is enforced to control access to one or more resources in a computer network. In one embodiment, a method includes: (i) receiving a reverse query and a set of admissible access requests, each of which includes one or more attributes in the policy and values of these; (ii) extracting attributes to which all access requests in the set assign identical values; (iii) reducing the ABAC policy by substituting values for the extracted attributes; (iv) caching the policy as a simplified policy; (v) translating the simplified policy and the given decision into a satisfiable logic proposition; (vi) deriving all solutions satisfying the proposition; and (vi) extracting, based on the solutions, all access requests from the set for which the policy yields the given decision.

Abstract: Real-time techniques for determining all access requests to an attribute-based access control policy which evaluate to a given decision, “permit” or “deny”. The policy is enforced to control access to one or more resources in a computer network. In one embodiment, a method includes: (i) receiving a reverse query and a set of admissible access requests, each of which includes one or more attributes in the policy and values of these; (ii) extracting attributes to which all access requests in the set assign identical values; (iii) reducing the ABAC policy by substituting values for the extracted attributes; (iv) caching the policy as a simplified policy; (v) translating the simplified policy and the given decision into a satisfiable logic proposition; (vi) deriving all solutions satisfying the proposition; and (vi) extracting, based on the solutions, all access requests from the set for which the policy yields the given decision.

Abstract: Real-time techniques for determining all access requests to an attribute-based access control policy which evaluate to a given decision, “permit” or “deny”. The policy is enforced to control access to one or more resources in a computer network. In one embodiment, a method includes: (i) receiving a reverse query and a set of admissible access requests, each of which includes one or more attributes in the policy and values of these; (ii) extracting attributes to which all access requests in the set assign identical values; (iii) reducing the ABAC policy by substituting values for the extracted attributes; (iv) caching the policy as a simplified policy; (v) translating the simplified policy and the given decision into a satisfiable logic proposition; (vi) deriving all solutions satisfying the proposition; and (vi) extracting, based on the solutions, all access requests from the set for which the policy yields the given decision.

Abstract: A method is disclosed, and a corresponding data carrier and policy converter, for producing at least one Security Descriptor Definition Language, SDDL, rule from an eXtensible Access Control Markup Language, XACML, policy (P), wherein said at least one SDDL rule is enforceable for controlling access to one or more resources in a computer network. A reverse query is produced indicating a given decision (d), which is one of permit access and deny access, and a set (R) of admissible access requests. Based on the reverse query, the XACML policy (P) and the given decision (d) are translated into a satisfiable logic proposition in Boolean variables (vi, i=1, 2, . . . ) From said ROBDD, variable assignments (RCj=[ARCj1: v1=xj1, ARCj2: v2=xj2, . . . ], j=1, 2, . . . ) satisfying the logic proposition are derived and at least one SDDL rule is created based on said variable assignments (RCj=[ARCj1: v1=xj1, ARCj2: v2=xj2, . . . ], j=1, 2, . . . ) satisfying the logic proposition.

Abstract: Disclosed are methods and devices for provisioning authorization claims, which are enforced to control access of users to objects (resources) in a computer system, and which are to be equivalent to an attribute-based access control (ABAC) policy. A policy converter according to the invention includes a policy processor processing the policy by partial evaluation against attribute values of the users, objects or permission levels in the system and outputting simplified policies, which are subject to reverse evaluation in a reverse policy evaluator, whereby users, objects and permission levels to be associated by way of a single authorization claim are obtained. Responsible for the defining of the authorization claim and its distribution in the computer system are an authorization claim generator and an authorization claim distribution interface. The invention may be so configured as to return a single authorization claim for each combination of an object and a permission level.

Abstract: An attribute-based policy defining subjects' access to resources is enforced by a computer system. A processing means (PDP) in the system communicates with a nearby attribute value source and at least one remote attribute value source and is adapted to evaluate the policy for an access request containing one or more explicit attribute values, which together with the policy define at least one implicit reference to a further attribute value, which is retrievable from one of said attribute value sources. The processing means reduces the policy by substituting attribute values for attributes in the policy if they are contained in the request or retrievable from the nearby source. References to further attributes retrievable from a remote source only are cached together with intermediate results. All attribute values from a given remote source are retrieved on one occasion, and the intermediate results are used to terminate the evaluation.

Abstract: An attribute-based access control policy (e.g., XACML policy) for a set of elements depends on attributes carried by elements in one of several predefined categories. In order to evaluate such policy for a set of elements, the invention provides a method including the steps of (I) selecting a primary category; (II) partitioning the elements in the primary category into equivalence classes with respect to their influence on the policy; and (III) using the equivalence classes to replace at least one policy evaluation by a deduction. The result of the evaluation may be represented as an access matrix in backward-compatible format. The efficiency of the policy evaluation may be further improved by applying partial policy evaluation at intermediate stages, by forming combined equivalence classes containing n-tuples of elements and/or by analyzing the influence of each element by extracting functional expressions of maximal length from the policy.

Abstract: Real-time techniques for determining all access requests to an attribute-based access control policy which evaluate to a given decision, “permit” or “deny”. The policy is enforced to control access to one or more resources in a computer network. In one embodiment, a method includes: (i) receiving a reverse query and a set of admissible access requests, each of which includes one or more attributes in the policy and values of these; (ii) extracting attributes to which all access requests in the set assign identical values; (iii) reducing the ABAC policy by substituting values for the extracted attributes; (iv) caching the policy as a simplified policy; (v) translating the simplified policy and the given decision into a satisfiable logic proposition; (vi) deriving all solutions satisfying the proposition; and (vi) extracting, based on the solutions, all access requests from the set for which the policy yields the given decision.

Abstract: Real-time techniques for determining all access requests to an attribute-based access control policy which evaluate to a given decision, “permit” or “deny”. The policy is enforced to control access to one or more resources in a computer network. In one embodiment, a method includes: (i) receiving a reverse query and a set of admissible access requests, each of which includes one or more attributes in the policy and values of these; (ii) extracting attributes to which all access requests in the set assign identical values; (iii) reducing the ABAC policy by substituting values for the extracted attributes; (iv) caching the policy as a simplified policy; (v) translating the simplified policy and the given decision into a satisfiable logic proposition; (vi) deriving all solutions satisfying the proposition; and (vi) extracting, based on the solutions, all access requests from the set for which the policy yields the given decision.

Abstract: A method is disclosed, and a corresponding data carrier and policy converter, for producing at least one Security Descriptor Definition Language, SDDL, rule from an eXtensible Access Control Markup Language, XACML, policy (P), wherein said at least one SDDL rule is enforceable for controlling access to one or more resources in a computer network. A reverse query is produced indicating a given decision (d), which is one of permit access and deny access, and a set (R) of admissible access requests. Based on the reverse query, the XACML policy (P) and the given decision (d) are translated into a satisfiable logic proposition in Boolean variables (vi, i=1, 2, . . . ) From said ROBDD, variable assignments (RCj=[ARCj1:v1=xj1, ARCj2:v2=xj2, . . . ], j=1, 2, . . . ) satisfying the logic proposition are derived and at least one SDDL rule is created based on said variable assignments (RCj=[ARCj1:v1=xj1, ARCj2:v2=xj2, . . . ], j=1, 2, . . . ) satisfying the logic proposition.

Abstract: An attribute-based access control policy (e.g., XACML policy) for a set of elements depends on attributes carried by elements in one of several predefined categories. In order to evaluate such policy for a set of elements, the invention provides a method including the steps of (I) selecting a primary category; (II) partitioning the elements in the primary category into equivalence classes with respect to their influence on the policy; and (III) using the equivalence classes to replace at least one policy evaluation by a deduction. The result of the evaluation may be represented as an access matrix in backward-compatible format. The efficiency of the policy evaluation may be further improved by applying partial policy evaluation at intermediate stages, by forming combined equivalence classes containing n-tuples of elements and/or by analyzing the influence of each element by extracting functional expressions of maximal length from the policy.

Abstract: Disclosed are methods and devices for provisioning authorization claims, which are enforced to control access of users to objects (resources) in a computer system, and which are to be equivalent to an attribute-based access control (ABAC) policy. A policy converter according to the invention includes a policy processor processing the policy by partial evaluation against attribute values of the users, objects or permission levels in the system and outputting simplified policies, which are subject to reverse evaluation in a reverse policy evaluator, whereby users, objects and permission levels to be associated by way of a single authorization claim are obtained. Responsible for the defining of the authorization claim and its distribution in the computer system are an authorization claim generator and an authorization claim distribution interface. The invention may be so configured as to return a single authorization claim for each combination of an object and a permission level.

Abstract: A method is disclosed, and a corresponding data carrier and policy converter, for producing at least one Security Descriptor Definition Language, SDDL, rule from an eXtensible Access Control Markup Language, XACML, policy (P), wherein said at least one SDDL rule is enforceable for controlling access to one or more resources in a computer network. A reverse query is produced indicating a given decision (d), which is one of permit access and deny access, and a set (R) of admissible access requests. Based on the reverse query, the XACML policy (P) and the given decision (d) are translated into a satisfiable logic proposition in Boolean variables (vi, i=1, 2, . . . ) From said ROBDD, variable assignments (RCj=[ARCj1: v1=xj1, ARCj2: v2=xj2, . . . ], j=1, 2, . . . ) satisfying the logic proposition are derived and at least one SDDL rule is created based on said variable assignments (RCj=[ARCj1: v1=xj1, ARCj2: v2=xj2, . . . ], j=1, 2, . . . ) satisfying the logic proposition.

Abstract: Disclosed are methods and devices for provisioning authorization claims, which are enforced to control access of users to objects (resources) in a computer system (330), and which are to be equivalent to an attribute-based access control (ABAC) policy. A policy converter according to the invention includes a policy processor (310) processing the policy by partial evaluation against attribute values of the users, objects or permission levels in the system and outputting simplified policies, which are subject to reverse evaluation in a reverse policy evaluator (320), whereby users, objects and permission levels to be associated by way of a single authorization claim are obtained. Responsible for the defining of the authorization claim and its distribution in the computer system are an authorization claim generator (330) and an authorization claim distribution interface (340). The invention may be so configured as to return a single authorization claim for each combination of an object and a permission level.

Abstract: An attribute-based access control policy (e.g., XACML policy) for a set of elements depends on attributes carried by elements in one of several predefined categories. In order to evaluate such policy for a set of elements, the invention provides a method including the steps of (I) selecting a primary category; (II) partitioning the elements in the primary category into equivalence classes with respect to their influence on the policy; and (III) using the equivalence classes to replace at least one policy evaluation by a deduction. The result of the evaluation may be represented as an access matrix in backward-compatible format. The efficiency of the policy evaluation may be further improved by applying partial policy evaluation at intermediate stages, by forming combined equivalence classes containing n-tuples of elements and/or by analyzing the influence of each element by extracting functional expressions of maximal length from the policy.

Abstract: An attribute-based policy defining subjects' access to resources is enforced by a computer system. A processing means (PDP) in the system communicates with a nearby attribute value source and at least one remote attribute value source and is adapted to evaluate the policy for an access request containing one or more explicit attribute values, which together with the policy define at least one implicit reference to a further attribute value, which is retrievable from one of said attribute value sources. The processing means reduces the policy by substituting attribute values for attributes in the policy if they are contained in the request or retrievable from the nearby source. References to further attributes retrievable from a remote source only are cached together with intermediate results. All attribute values from a given remote source are retrieved on one occasion, and the intermediate results are used to terminate the evaluation.

Abstract: An attribute-based access control policy (e.g., XACML policy) for a set of elements depends on attributes carried by elements in one of several predefined categories. In order to evaluate such policy for a set of elements, the invention provides a method including the steps of (I) selecting a primary category; (II) partitioning the elements in the primary category into equivalence classes with respect to their influence on the policy; and (III) using the equivalence classes to replace at least one policy evaluation by a deduction. The result of the evaluation may be represented as an access matrix in backward-compatible format. The efficiency of the policy evaluation may be further improved by applying partial policy evaluation at intermediate stages, by forming combined equivalence classes containing n-tuples of elements and/or by analyzing the influence of each element by extracting functional expressions of maximal length from the policy.

Abstract: Disclosed are real-time techniques for determining all access requests to an attribute-based access control policy which evaluate to a given decision, “permit” or “deny”. The policy is enforced to control access to one or more resources in a computer network. In one embodiment, a method comprises: (i) receiving a reverse query and a set of admissible access requests, each of which comprises one or more attributes in the policy and values of these; (ii) extracting attributes to which all access requests in the set assign identical values; (iii) reducing the ABAC policy by substituting values for the extracted attributes; (iv) caching the policy as a simplified policy; (v) translating the simplified policy and the given decision into a satisfiable logic proposition; (vi) deriving all solutions satisfying the proposition; and (vi) extracting, based on the solutions, all access requests from the set for which the policy yields the given decision.