pprl-model 0.1.5

Data models for use with a HTTP-based service for privacy-preserving record linkage using Bloom filters.

This package contains model classes that are used in the PPRL service for validation purposes. They have been conceived with the idea of an HTTP-based service for record linkage based on Bloom filters in mind. It encompasses models for the service's data transformation, masking and bit vector matching routines. Pydantic is used for validation, serialization and deserialization. This package is rarely to be used directly. Instead, it is used by other packages to power their functionalities.

Data models

Models for entity pre-processing, masking and bit vector matching are exposed through this package. The following examples are taken from the test suites of the PPRL service package and show additional validation steps in addition to the ones native to Pydantic.

Entity transformation

from pprl_model import EntityTransformRequest, TransformConfig, EmptyValueHandling, AttributeValueEntity, \
    AttributeTransformerConfig, NumberTransformer, GlobalTransformerConfig, NormalizationTransformer, \
    CharacterFilterTransformer

# This is a valid config.
_ = EntityTransformRequest(
    config=TransformConfig(empty_value=EmptyValueHandling.ignore),
    entities=[
        AttributeValueEntity(
            id="001",
            attributes={
                "bar1": "  12.345  ",
                "bar2": "  12.345  "
            }
        )
    ],
    attribute_transformers=[
        AttributeTransformerConfig(
            attribute_name="bar1",
            transformers=[
                NumberTransformer(decimal_places=2)
            ]
        )
    ],
    global_transformers=GlobalTransformerConfig(
        before=[
            NormalizationTransformer()
        ],
        after=[
            CharacterFilterTransformer(characters=".")
        ]
    )
)

from uuid import uuid4

# Validation will fail since no transformers have been defined.
_ = EntityTransformRequest(
    config=TransformConfig(empty_value=EmptyValueHandling.ignore),
    entities=[
        AttributeValueEntity(
            id=str(uuid4()),
            attributes={
                "foo": "bar"
            }
        )
    ],
    attribute_transformers=[]
)
# => ValidationError: attribute and global transformers are empty: must contain at least one

Entity masking

from pprl_model import EntityMaskRequest, MaskConfig, HashConfig, HashFunction, HashAlgorithm, \
    DoubleHash, CLKFilter, AttributeValueEntity, StaticAttributeConfig, AttributeSalt, CLKRBFFilter

# This is a valid config.
_ = EntityMaskRequest(
    config=MaskConfig(
        token_size=2,
        hash=HashConfig(
            function=HashFunction(algorithms=[HashAlgorithm.sha1]),
            strategy=DoubleHash()
        ),
        filter=CLKFilter(filter_size=1024, hash_values=5),
        padding="_"
    ),
    entities=[
        AttributeValueEntity(
            id="001",
            attributes={
                "first_name": "John",
                "last_name": "Doe",
                "date_of_birth": "1987-06-05",
                "gender": "m"
            }
        )
    ]
)

# This is an invalid config since salting an attribute can only be done through a fixed value
# or another attribute on an entity, not both at the same time.
_ = EntityMaskRequest(
    config=MaskConfig(
        token_size=2,
        hash=HashConfig(
            function=HashFunction(algorithms=[HashAlgorithm.sha1]),
            strategy=DoubleHash()
        ),
        filter=CLKFilter(filter_size=1024, hash_values=5),
        padding="_"
    ),
    entities=[
        AttributeValueEntity(
            id="001",
            attributes={
                "first_name": "foobar",
                "salt": "0123456789"
            }
        )
    ],
    attributes=[
        StaticAttributeConfig(
            attribute_name="first_name",
            salt=AttributeSalt(
                value="my_salt",
                attribute="salt"
            )
        )
    ]
)
# => ValidationError: value and attribute cannot be set at the same time

# This also fails if neither a static value nor an attribute are set for salting.
_ = EntityMaskRequest(
    config=MaskConfig(
        token_size=2,
        hash=HashConfig(
            function=HashFunction(algorithms=[HashAlgorithm.sha1]),
            strategy=DoubleHash()
        ),
        filter=CLKFilter(filter_size=1024, hash_values=5),
        padding="_"
    ),
    entities=[
        AttributeValueEntity(
            id="001",
            attributes={
                "first_name": "foobar",
                "salt": "0123456789"
            }
        )
    ],
    attributes=[
        StaticAttributeConfig(
            attribute_name="first_name",
            salt=AttributeSalt()
        )
    ]
)
# => ValidationError: neither value nor attribute is set

# When using a weighted filter (RBF, CLKRBF), an error will be thrown if any attribute configuration 
# provided is static, not weighted. The same applies vice versa, meaning if CLK is specified as a filter and
# weighted attribute configurations are provided.
_ = EntityMaskRequest(
    config=MaskConfig(
        token_size=2,
        hash=HashConfig(
            function=HashFunction(algorithms=[HashAlgorithm.sha1]),
            strategy=DoubleHash()
        ),
        filter=CLKRBFFilter(hash_values=5),
        padding="_"
    ),
    entities=[
        AttributeValueEntity(
            id="001",
            attributes={
                "first_name": "foobar",
                "salt": "0123456789"
            }
        )
    ],
    attributes=[
        StaticAttributeConfig(
            attribute_name="first_name",
            salt=AttributeSalt(value="my_salt")
        )
    ]
)
# => ValidationError: `clkrbf` filters require weighted attribute configurations, but static ones were found

# Weighted filters (RBF, CLKRBF) always require weighted attribute configurations. If none
# are provided, validation fails.
_ = EntityMaskRequest(
    config=MaskConfig(
        token_size=2,
        hash=HashConfig(
            function=HashFunction(algorithms=[HashAlgorithm.sha1]),
            strategy=DoubleHash()
        ),
        filter=CLKRBFFilter(hash_values=5),
        padding="_"
    ),
    entities=[
        AttributeValueEntity(
            id="001",
            attributes={
                "first_name": "foobar",
                "salt": "0123456789"
            }
        )
    ]
)
# => ValidationError: `clkrbf` filters require weighted attribute configurations, but none were found

# If a configuration is provided for an attribute that doesn't exist on some entities, validation fails.
_ = EntityMaskRequest(
    config=MaskConfig(
        token_size=2,
        hash=HashConfig(
            function=HashFunction(algorithms=[HashAlgorithm.sha1]),
            strategy=DoubleHash()
        ),
        filter=CLKFilter(filter_size=1024, hash_values=5),
        padding="_"
    ),
    entities=[
        AttributeValueEntity(
            id="001",
            attributes={
                "first_name": "foobar"
            }
        )
    ],
    attributes=[
        StaticAttributeConfig(
            attribute_name="last_name",
            salt=AttributeSalt(value="my_salt")
        )
    ]
)
# => ValidationError: some configured attributes are not present on entities: `last_name` on entities with ID `001`

Bit vector matching

from pprl_model import VectorMatchRequest, MatchConfig, SimilarityMeasure, BitVectorEntity

_ = VectorMatchRequest(
    config=MatchConfig(
        measure=SimilarityMeasure.jaccard,
        threshold=0.8
    ),
    domain=[
        BitVectorEntity(
            id="D001",
            value="kY7yXn+rmp8L0nyGw5NlMw=="
        )
    ],
    range=[
        BitVectorEntity(
            id="R001",
            value="qig0C1i8YttqhPwo4VqLlg=="
        )
    ]
)

License

MIT.