kaplan_meier.data_owner module

Module implements the data owners Alice and Bob.

class kaplan_meier.data_owner.Alice(*args, nr_of_threads=4, **kwargs)[source]

Bases: DataOwner

Alice player in the MPC protocol

__init__(*args, nr_of_threads=4, **kwargs)[source]

Initializes player Alice

Parameters

nr_of_threads (int) – the number of threads to use for randomness generation
args (Any) – arguments to pass on to base class
kwargs (Any) – keyword arguments to pass on to base class

property cols_in_hidden_table: int

Number of columns in the hidden table. Two columns per group; one for the number of events on a given event time and one for the number of people at risk at that time.

Return type: int
Returns: number of columns in the hidden table

compute_factors()[source]

Pre-computes several factors for in the computation of the log- rank statistic, leveraging information known by Alice only.

Computes the following factors: dev_factors, var_factors, var_factors_2. These factors satisfy the following relations:

Expected number of deaths in group i =
dev_factors[i] * at_risk_group[i]

Variance of deaths in group i =
(var_factors_2[i] - var_factors[i] * at_risk_group[i]) * at_risk_group[i]

Return type: None

compute_hidden_table()[source]

Method to compute the hidden table of the protocol.

Return type: None

generate_share()[source]

Generates additive secret shares.

Return type: None

property groups: int

Number of groups in the datasets

Return type: int
Returns: number of groups
Raises: ValueError – raised when number of groups is not available (yet)

property hidden_table: ndarray[PaillierCiphertext]

Hidden table

Return type: ndarray[PaillierCiphertext]
Returns: the constructed hidden table
Raises: ValueError – raised when hidden table is not yet available.

mask_hidden_table()[source]

Masks the hidden table.

Return type: ndarray[float64]
Returns: a masked hidden table

property plain_table: ndarray[int32]

Plain table

Return type: ndarray[int32]
Returns: plaintext result of some computation in table format
Raises: ValueError – raised when plain table is not yet available.

re_randomise_ht()[source]

Re-randomises the hidden table

Return type: None

static re_randomize(ciphertext)[source]

Re-randomises a ciphertext

Parameters: ciphertext (PaillierCiphertext) – ciphertext to randomize
Return type: None

async receive_encrypted_group_data()[source]

Method to receive the encrypted group data from party Bob.

Return type: None

async receive_number_of_groups()[source]

Method to receive the number of groups identified by party Bob.

Return type: None

async receive_paillier_scheme()[source]

Method to receive the Paillier scheme that is used by party Bob.

Return type: None

property rows_in_hidden_table: int

Number of rows in the hidden table. Equals number of unique event times (ignoring censorings).

Return type: int
Returns: number of rows in the hidden table

async send_share()[source]

Sends additive secret share to party Bob.

Return type: None

signed_randomness()[source]

Returns a signed random plaintext value.

Return type: SupportsInt
Returns: signed random plaintext value

async start_protocol()[source]

Starts and runs the protocol

Return type: None

start_randomness_generation()[source]

Kicks off the randomness generation. This boosts performance. In particular will this decrease the total runtime (as data owners can already generate randomness before they need it).

Return type: None

class kaplan_meier.data_owner.Bob(*args, paillier_scheme=<tno.mpc.encryption_schemes.paillier.paillier.Paillier object>, **kwargs)[source]

Bases: DataOwner

Bob player in the MPC protocol

__init__(*args, paillier_scheme=<tno.mpc.encryption_schemes.paillier.paillier.Paillier object>, **kwargs)[source]

Initializes player Bob

Parameters

paillier_scheme (Paillier) – the Paillier scheme to use for encryption
args (Any) – arguments to pass on to base class
kwargs (Any) – keyword arguments to pass on to base class

async decrypt_share(data)[source]

Decrypt share

Parameters: data (ndarray[PaillierCiphertext]) – the dataset (share) to decrypt
Return type: Any
Returns: decrypted data set

property groups: int

Number of groups in the loaded dataset

Return type: int
Returns: number of groups

async receive_share()[source]

Receive additive secret share produced by party Alice.

Return type: None

async send_encrypted_data()[source]

Sends the encrypted dataset to party Alice.

Return type: None

async send_number_of_groups()[source]

Sends the number of groups to party Alice.

Return type: None

async send_paillier_scheme()[source]

Sends the used Paillier scheme to party Alice.

Return type: None

async start_protocol()[source]

Starts and runs the protocol

Return type: None

class kaplan_meier.data_owner.DataOwner(data, pool, *args, **kwargs)[source]

Bases: Player

Data owner in the MPC protocol

__init__(data, pool, *args, **kwargs)[source]

Initializes data owner

Parameters

data (DataFrame) – the data to use for this data owner
pool (Pool) – a communication pool
args (Any) – arguments to pass on to base class
kwargs (Any) – keyword arguments to pass on to base class

property data: Union[DataFrame, ndarray[int32]]

The loaded dataset

Return type: Union[DataFrame, ndarray[int32]]
Returns: dataset
Raises: ValueError – raised when there is no data available

decrypt(data)[source]

Method to decrypt a dataset using the initialized Paillier scheme

Parameters: data (ndarray[PaillierCiphertext]) – the dataset to decrypt
Return type: ndarray[Any]
Returns: a decrypted dataset

encrypt(data)[source]

Method to encrypt a dataset using the initialized Paillier scheme

Parameters: data (ndarray[float64]) – the dataset to encrypt
Return type: ndarray[PaillierCiphertext]
Returns: an encrypted dataset

property groups: int

Number of groups in the loaded datasets

Return type: int
Returns: number of groups
Raises: NotImplementedError – raised when not implemented

property paillier_scheme: Paillier

The Paillier scheme

Return type: Paillier
Returns: Paillier scheme
Raises: ValueError – raised when Paillier scheme is not available yet.

async receive_message(party, msg_id=None)[source]

Receives a message from a party (belonging to an optional message identifier)

Parameters

party (str) – the party to receive a message from
msg_id (Optional[str]) – the message id

Return type

Any

Returns

the received message

property records: int

Number of records in the loaded dataset

Return type: int
Returns: number of records

async send_message(receiver, message, msg_id=None)[source]

Sends a message to a party (with an optional message identifier)

Parameters

receiver (str) – the party to send a message to
message (Any) – the message to send
msg_id (Optional[str]) – the message id

Return type

None

stop_randomness_generation()[source]

Stop generation of randomness.

Return type: None