makeShare

This function is called to split the original data of node 0 (compute party) and node 1 (non-compute party) into shares. When node 0 calls this function, it sets isRecvShare to 1 to receive the shares sent by node 1, and then sets isRecvShare to 0 to split its own data into shares. When the non-compute party calls this function, it sets isRecvShare to 0 to split its own data into shares and then sends the shares to the compute party.

int makeShare(
    DG_TeeCtx *dgTeeCtx,
    int isRecvShare,
    DG_TeeMatInput *input,
    DG_MpcMatShare **share 
)

Parameters

Parameter	Description	Value Range	Input/Output
dgTeeCtx	KCAL context	Context initialized in section initTeeCtx.	Input
isRecvShare	0: Splits the original data of a node itself into shares. 1: Receives data shares of the other node.	0 or 1.	Input
input	This is the original data. Only when isRecvShare is set to 0, input can be null.	Currently, only the double type is supported.	Input
share	The type of the matrix share result: DG_MpcMatShare	It is null as a single pointer and cannot be null as a double pointer.	Output

**Table 1** DG_TeeMatInput structure
Member	Type	Description
data	DG_MpcDataUnion	The types of the input data strings, doubleNumbers, and u64Numbers are respectively DG_String , double , and u64 *.
row	uint32_t	Number of rows in a matrix
col	uint32_t	Number of columns in a matrix
dataType	DG_MpcDataType	The enumerated data type is as follows: MPC_DOUBLE (cryptographic matrix addition, subtraction, and multiplication)

**Table 2** DG_MpcDataUnion
Member	Type	Description
strings	DG_String	String array
u64Numbers	u64	u64 array
doubleNumbers	double	Double array

**Table 3** DG_MpcMatShare structure
Member	Type	Description
dataShare	Share	Share structure
row	unsigned long	Number of rows in a matrix
col	unsigned long	Number of columns in a matrix
shareType	DG_ShareType	Share type

ShareType
enum DG_ShareType {
    FIX_POINT, // Fixed-point number
    NON_FIX_POINT // Non-fixed-point number
};

**Table 4** Share structure
Member	Type	Description
shares	u64*	Multiple shares corresponding to one piece of plaintext data
size	u64	The number of shares

Return Values

Success: 0 is returned.
Failure: The error code is returned.

Error Codes

Error Code	Value	Description	Remarks
DG_FAILURE	4501	Data share splitting failure	Failed to verify the parameters. Failed to split data into shares. Failed to receive data from the other node.

Error Code

Value

Description

Remarks

DG_FAILURE

4501

Data share splitting failure

Failed to verify the parameters.

Failed to split data into shares.

Failed to receive data from the other node.

Dependency

aritOpts depends on the successful initialization in section DG_InitMatrixOpts of the function group for matrix arithmetic operators.
You need to call the negotiateSeeds API to distribute seeds to all nodes.
#include "data_guard_mpc.h": required header file

Example

#include  "data_guard_mpc.h"
std::unique_ptr<double[]> inData = std::make_unique<double[]>(datas.size());
for (int i = 0; i < datas.size(); i++) {
    inData[i] = (std::stod(datas[i].c_str())) * 1.0;
}
// DG_TeeMatInput teeInput indicates the data shares from the compute party.
teeInput.data.doubleNumbers = inData.get();
teeInput.row = row; // Assume that the number of rows in the matrix is row.
teeInput.col = col; // Assume that the number of columns in the matrix is col.
teeInput.dataType = MPC_DOUBLE;
printf("++++++++++input data size:%lu\n", teeInput.size);
int res = aritOpts.negotiateSeeds(dgTee);
printf("exchange seed res = %d\n", res);
DG_MpcMatShareSet shareDat;
std::unique_ptr<DG_MpcMatShare[]> share = std::make_unique<DG_MpcMatShare[]>(2);
DG_MpcMatShare *share1 = nullptr;
DG_MpcMatShare *share2 = nullptr;
DG_TeeMatOutput *output = nullptr;
if (nodeId == 0) {
res = aritOpts.makeShare(dgTee, 1, nullptr, &share1);  // &teeInput

Note: The example is for reference only. It describes how to read data from a file for testing and cannot be executed.

Test result: res is 0 and the shares are not null.

Call the makeShare API using the aritOpts output of the successful DG_InitMatrixOpts call.
If either node (node 0 or 1) returns an error code when calling an API, the node needs to use a task scheduling mechanism to notify the other node to terminate the service process. For example, if node 1 returns an error code when calling the makeShare API and node 0 is waiting to receive shares, node 1 needs to notify node 0 to stop receiving.

Parent topic: Matrix Arithmetic Operators