Package org.apache.sysds.runtime.privacy.propagation

Class PrivacyPropagator

  • public class PrivacyPropagator
extends Object
    Class with static methods merging privacy constraints of operands in expressions to generate the privacy constraints of the output.

    • Constructor Detail

      • PrivacyPropagator

        public PrivacyPropagator()

    • Method Detail

      • parseAndSetPrivacyConstraint

        public static Data parseAndSetPrivacyConstraint​(Data cd,
                                                org.apache.wink.json4j.JSONObject mtd)
                                         throws org.apache.wink.json4j.JSONException
        Parses the privacy constraint of the given metadata object and sets the field of the given Data if the privacy constraint is not null.
        Parameters:
        cd - data for which privacy constraint is set
        mtd - metadata object
        Returns:
        data object with privacy constraint set
        Throws:
        org.apache.wink.json4j.JSONException - during parsing of metadata

      • parseAndReturnPrivacyConstraint

        public static PrivacyConstraint parseAndReturnPrivacyConstraint​(org.apache.wink.json4j.JSONObject mtd)
                                                         throws org.apache.wink.json4j.JSONException
        Parses the privacy constraint of the given metadata object or returns null if no privacy constraint is set in the metadata.
        Parameters:
        mtd - metadata
        Returns:
        privacy constraint parsed from metadata object
        Throws:
        org.apache.wink.json4j.JSONException - during parsing of metadata

      • corePropagation

        public static PrivacyConstraint.PrivacyLevel corePropagation​(PrivacyConstraint.PrivacyLevel[] inputLevels,
                                                             OperatorType operatorType)
        Returns the output privacy level based on the given input privacy levels and operator type. It represents the basic logic of privacy propagation: Unary input: Input | NonAggregate | Aggregate ----------------------------------- priv | priv | priv privAgg | privAgg | none none | none | none Binary input: Input | NonAggregate | Aggregate -------------------------------------------- priv-priv | priv | priv priv-privAgg | priv | priv priv-none | priv | priv privAgg-priv | priv | priv none-priv | priv | priv privAgg-privAgg | privAgg | none none-none | none | none privAgg-none | privAgg | none none-privAgg | privAgg | none
        Parameters:
        inputLevels - privacy levels of the input
        operatorType - type of the operator which is either an aggregation (Aggregate) or not an aggregation (NonAggregate)
        Returns:
        output privacy level

      • mergeBinary

        public static PrivacyConstraint mergeBinary​(PrivacyConstraint privacyConstraint1,
                                            PrivacyConstraint privacyConstraint2)
        Merges the input privacy constraints using the core propagation with NonAggregate operator type.
        Parameters:
        privacyConstraint1 - first privacy constraint
        privacyConstraint2 - second privacy constraint
        Returns:
        merged privacy constraint

      • hopPropagation

        public static void hopPropagation​(Hop hop)
        Propagate privacy constraints from input hops to given hop.
        Parameters:
        hop - which the privacy constraints are propagated to

      • hopPropagation

        public static void hopPropagation​(Hop hop,
                                  ArrayList<Hop> inputHops)
        Propagate privacy constraints from input hops to given hop.
        Parameters:
        hop - which the privacy constraints are propagated to
        inputHops - inputs to given hop

      • postProcessInstruction

        public static void postProcessInstruction​(Instruction inst,
                                          ExecutionContext ec)
        Propagate privacy constraints to output variables based on privacy constraint of CPOperand output in instruction which has been set during privacy propagation preprocessing.
        Parameters:
        inst - instruction for which privacy constraints are propagated
        ec - execution context

      • preprocessInstruction

        public static Instruction preprocessInstruction​(Instruction inst,
                                                ExecutionContext ec)
        Propagate privacy constraints from input to output CPOperands in case the privacy constraints of the input are activated.
        Parameters:
        inst - instruction for which the privacy constraints are propagated
        ec - execution context
        Returns:
        instruction with propagated privacy constraints (usually the same instance as the input inst)