A class generating public keys from secret keys provided by multiple parties. More...

#include <CollectiveKeyGenerator.hpp>

Public Member Functions
	CollectiveKeyGenerator (const Context &context)
	Construct a `CollectiveKeyGenerator` object with a given context. More...

	CollectiveKeyGenerator (const Context &context, const Context &context_sparse)
	Construct a module for generating collective key including keys for sparse secret encapsulation for the given context. More...

CollectiveKeyGenData	genCommonRandomData (const CollectiveKeyGenConfig &config) const
	Generate a random data to be shared among parties for collective key generation. More...

CollectiveKeyGenData	genKeyShare (const SecretKey &sk, const CollectiveKeyGenData &crd) const
	Generate key share, the data which can be aggregated to generate collective key for encryption / conjugation / rotation / sparse secret encapsulation. More...

CollectiveKeyGenData	aggregateKeyShare (const std::vector< const CollectiveKeyGenData * > &parts) const
	Aggregate key share from each party. More...

CollectiveKeyGenData	genMultKeyShareRoundOne (const SecretKey &sk, const SecretKey &tmp_sk, const CollectiveKeyGenData &crd) const
	Perform round one for collective mult(relinearization) key generation. More...

CollectiveKeyGenData	genMultKeyShareRoundTwo (const SecretKey &sk, const SecretKey &tmp_sk, const CollectiveKeyGenData &data_round_one) const
	Perform round two for collective mult(relinearization) key generation. More...

std::shared_ptr< EncryptionKey >	genEncKey (const CollectiveKeyGenData &crd, const CollectiveKeyGenData &agg) const
	Collectively generate key for encryption. More...

std::shared_ptr< EvaluationKey >	genConjKey (const CollectiveKeyGenData &crd, const CollectiveKeyGenData &agg) const
	Collectively generate key for conjugation. More...

std::shared_ptr< EvaluationKey >	genRotKey (const CollectiveKeyGenData &crd, const CollectiveKeyGenData &agg) const
	Collectively generate key for rotation. More...

std::shared_ptr< EvaluationKey >	genMultKey (const CollectiveKeyGenData &data_round_one, const CollectiveKeyGenData &data_round_two) const
	Collectively generate key for multiplication. More...

std::shared_ptr< SparseSecretEncapsulationKey >	genSparseSecretEncapsulationKey (const CollectiveKeyGenData &crd, const CollectiveKeyGenData &agg) const
	Collectively generate key for sparse secret encapsulation. More...

Private Attributes
std::shared_ptr< CollectiveKeyGeneratorImpl >	impl_

Detailed Description

A class generating public keys from secret keys provided by multiple parties.

Generate collectively known public key for encryption / multiplication / conjugation / rotation / sparse secret encapsulation. The class member functions should be performed in sequential order.

Constructor & Destructor Documentation

◆ CollectiveKeyGenerator() [1/2]

HEaaN::CollectiveKeyGenerator::CollectiveKeyGenerator ( const Context & context )

explicit

Construct a CollectiveKeyGenerator object with a given context.

◆ CollectiveKeyGenerator() [2/2]

HEaaN::CollectiveKeyGenerator::CollectiveKeyGenerator	(	const Context &	context,
		const Context &	context_sparse
	)

explicit

Construct a module for generating collective key including keys for sparse secret encapsulation for the given context.

Exceptions

RuntimeException if context_sparse is not a context constructed with the corresponding sparse parameter of which constructed context. Please refer to getSparseParameterPresetFor() on ParameterPreset.hpp for the sparse parameters.

Member Function Documentation

◆ aggregateKeyShare()

CollectiveKeyGenData HEaaN::CollectiveKeyGenerator::aggregateKeyShare ( const std::vector< const CollectiveKeyGenData * > & parts ) const

Aggregate key share from each party.

Parameters

[in] parts a vector of key shares obtained from genKeyShare().

Exceptions

RuntimeException if all the parts is not created to generate the same key.

Returns: Returns aggregated key share for the same key for which parts were generated. aggregated key share is used to generate collective key in genAndSaveCollectiveKey().

As computation which is performed on this function is addition, user may eagerly evaluate aggregation when only a subset of required CollectiveKeyGenData are prepared, as below : auto aggregated_part_AB = aggregateKeyShare({&part_A, &part_B}); auto aggregated_part_ABC = aggregateKeyShare({&aggregated_part_AB, &part_C});

◆ genCommonRandomData()

CollectiveKeyGenData HEaaN::CollectiveKeyGenerator::genCommonRandomData ( const CollectiveKeyGenConfig & config ) const

Generate a random data to be shared among parties for collective key generation.

Parameters

[in] config Configuration representing the key type for which collective key generated.

Returns: Returns a random data which can be used to generate key share in genKeyShare().

◆ genConjKey()

std::shared_ptr<EvaluationKey> HEaaN::CollectiveKeyGenerator::genConjKey	(	const CollectiveKeyGenData &	crd,
		const CollectiveKeyGenData &	agg
	)		const

Collectively generate key for conjugation.

Parameters

[in]	crd	Common random data obtained from genCommonRandomData().
[in]	agg	aggregated key share obtained from aggregateKeyShare().

Exceptions

RuntimeException if crd or agg are not created to generate conjugation key

◆ genEncKey()

std::shared_ptr<EncryptionKey> HEaaN::CollectiveKeyGenerator::genEncKey	(	const CollectiveKeyGenData &	crd,
		const CollectiveKeyGenData &	agg
	)		const

Collectively generate key for encryption.

Parameters

[in]	crd	Common random data obtained from genCommonRandomData().
[in]	agg	aggregated key share obtained from aggregateKeyShare().

Exceptions

RuntimeException if crd or agg are not created to generate encryption key

◆ genKeyShare()

CollectiveKeyGenData HEaaN::CollectiveKeyGenerator::genKeyShare	(	const SecretKey &	sk,
		const CollectiveKeyGenData &	crd
	)		const

Generate key share, the data which can be aggregated to generate collective key for encryption / conjugation / rotation / sparse secret encapsulation.

Parameters

[in]	sk	Secret key
[in]	crd	Common random data obtained from genCommonRandomData().

Returns: Returns key share for the same key for which crd was generated. key shares are aggregated by aggregateKeyShare().

◆ genMultKey()

std::shared_ptr<EvaluationKey> HEaaN::CollectiveKeyGenerator::genMultKey	(	const CollectiveKeyGenData &	data_round_one,
		const CollectiveKeyGenData &	data_round_two
	)		const

Collectively generate key for multiplication.

Parameters

[in]	data_round_one	Returned data from genMultKeyShareRoundOne().
[in]	data_round_two	Returned data from genMultKeyShareRoundTwo().

Exceptions

RuntimeException if data_round_one or data_round_two are not created to generate multiplication key

◆ genMultKeyShareRoundOne()

CollectiveKeyGenData HEaaN::CollectiveKeyGenerator::genMultKeyShareRoundOne	(	const SecretKey &	sk,
		const SecretKey &	tmp_sk,
		const CollectiveKeyGenData &	crd
	)		const

Perform round one for collective mult(relinearization) key generation.

Parameters

[in]	sk	Secret key
[in]	tmp_sk
[in]	crd	Common random data obtained from genCommonRandomData().

Exceptions

RuntimeException if crd is not generated for multiplication key

Returns: Returned data is used in genMultKeyShareRoundTwo().

◆ genMultKeyShareRoundTwo()

CollectiveKeyGenData HEaaN::CollectiveKeyGenerator::genMultKeyShareRoundTwo	(	const SecretKey &	sk,
		const SecretKey &	tmp_sk,
		const CollectiveKeyGenData &	data_round_one
	)		const

Perform round two for collective mult(relinearization) key generation.

Parameters

[in]	sk	Secret key
[in]	tmp_sk
[in]	data_round_one	Returned data from genMultKeyShareRoundOne().

Exceptions

RuntimeException if data_round_one is not generated for multiplication key

Returns: Returned data is used to generate collective key in genAndSaveCollectiveMultKey().

◆ genRotKey()

std::shared_ptr<EvaluationKey> HEaaN::CollectiveKeyGenerator::genRotKey	(	const CollectiveKeyGenData &	crd,
		const CollectiveKeyGenData &	agg
	)		const

Collectively generate key for rotation.

Parameters

[in]	crd	Common random data obtained from genCommonRandomData().
[in]	agg	aggregated key share obtained from aggregateKeyShare().

Exceptions

RuntimeException if crd or agg are not created to generate rotation key

◆ genSparseSecretEncapsulationKey()

std::shared_ptr<SparseSecretEncapsulationKey> HEaaN::CollectiveKeyGenerator::genSparseSecretEncapsulationKey	(	const CollectiveKeyGenData &	crd,
		const CollectiveKeyGenData &	agg
	)		const

Collectively generate key for sparse secret encapsulation.

Parameters

[in]	crd	Common random data obtained from genCommonRandomData().
[in]	agg	aggregated key share obtained from aggregateKeyShare().

Exceptions

RuntimeException if crd or agg are not created to generate sparse secret encapsulation key

Member Data Documentation

◆ impl_

std::shared_ptr<CollectiveKeyGeneratorImpl> HEaaN::CollectiveKeyGenerator::impl_

private

The documentation for this class was generated from the following file:

include/HEaaN/multiparty/CollectiveKeyGenerator.hpp

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ CollectiveKeyGenerator() [1/2]

◆ CollectiveKeyGenerator() [2/2]

Member Function Documentation

◆ aggregateKeyShare()

◆ genCommonRandomData()

◆ genConjKey()

◆ genEncKey()

◆ genKeyShare()

◆ genMultKey()

◆ genMultKeyShareRoundOne()

◆ genMultKeyShareRoundTwo()

◆ genRotKey()

◆ genSparseSecretEncapsulationKey()

Member Data Documentation

◆ impl_