ECNTT

ECNTT Method

The ECNtt[T any]() function performs the Elliptic Curve Number Theoretic Transform (EC-NTT) on the input points slice, using the provided dir (direction), cfg (configuration), and stores the results in the results slice.

func ECNtt[T any](points core.HostOrDeviceSlice, dir core.NTTDir, cfg *core.NTTConfig[T], results core.HostOrDeviceSlice) core.IcicleError

Parameters

• points: A slice of elliptic curve points (in projective coordinates) that will be transformed. The slice can be stored on the host or the device, as indicated by the core.HostOrDeviceSlice type.
• dir: The direction of the EC-NTT transform, either core.KForward or core.KInverse.
• cfg: A pointer to an NTTConfig object, containing configuration options for the NTT operation.
• results: A slice that will store the transformed elliptic curve points (in projective coordinates). The slice can be stored on the host or the device, as indicated by the core.HostOrDeviceSlice type.

Return Value

• CudaError: A core.IcicleError value, which will be core.IcicleErrorCode(0) if the EC-NTT operation was successful, or an error if something went wrong.

NTT Configuration (NTTConfig)

The NTTConfig structure holds configuration parameters for the NTT operation, allowing customization of its behavior to optimize performance based on the specifics of your protocol.

type NTTConfig[T any] struct {
    Ctx cr.DeviceContext
    CosetGen T
    BatchSize int32
    ColumnsBatch bool
    Ordering Ordering
    areInputsOnDevice  bool
    areOutputsOnDevice bool
    IsAsync bool
    NttAlgorithm NttAlgorithm
}

Fields

• Ctx: Device context containing details like device ID and stream ID.
• CosetGen: Coset generator used for coset (i)NTTs, defaulting to no coset being used.
• BatchSize: The number of NTTs to compute in one operation, defaulting to 1.
• ColumnsBatch: If true the function will compute the NTTs over the columns of the input matrix and not over the rows. Defaults to false.
• Ordering: Ordering of inputs and outputs (KNN, KNR, KRN, KRR), affecting how data is arranged.
• areInputsOnDevice: Indicates if input scalars are located on the device.
• areOutputsOnDevice: Indicates if results are stored on the device.
• IsAsync: Controls whether the NTT operation runs asynchronously.
• NttAlgorithm: Explicitly select the NTT algorithm. ECNTT supports running on Radix2 algoruithm.

Default Configuration

Use GetDefaultNTTConfig to obtain a default configuration, customizable as needed.

func GetDefaultNTTConfig[T any](cosetGen T) NTTConfig[T]

ECNTT Example

package main

import (
    "github.com/ingonyama-zk/icicle/v2/wrappers/golang/core"
    cr "github.com/ingonyama-zk/icicle/v2/wrappers/golang/cuda_runtime"
)

func Main() {
    // Obtain the default NTT configuration with a predefined coset generator.
    cfg := GetDefaultNttConfig()
    
    // Define the size of the input scalars.
    size := 1 << 18

    // Generate Points for the ECNTT operation.
    points := GenerateProjectivePoints(size)
    
    // Set the direction of the NTT (forward or inverse).
    dir := core.KForward

    // Allocate memory for the results of the NTT operation.
    results := make(core.HostSlice[Projective], size)

    // Perform the NTT operation.
    err := ECNtt(points, dir, &cfg, results)
    if err != cr.CudaSuccess {
        panic("ECNTT operation failed")
    }
}