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) runtime.EIcicleError

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

• EIcicleError: A runtime.EIcicleError value, which will be runtime.Success 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 {
	StreamHandle       runtime.Stream
	CosetGen           T
	BatchSize          int32
	ColumnsBatch       bool
	Ordering           Ordering
	areInputsOnDevice  bool
	areOutputsOnDevice bool
	IsAsync            bool
	Ext                config_extension.ConfigExtensionHandler
}

Fields

• StreamHandle: Specifies the stream (queue) to use for async execution.
• CosetGen: Coset generator. Used to perform coset (i)NTTs.
• 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.
• 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.
• Ext: Extended configuration for backend.

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/v3/wrappers/golang/core"
	"github.com/ingonyama-zk/icicle/v3/wrappers/golang/curves/bn254"
	"github.com/ingonyama-zk/icicle/v3/wrappers/golang/curves/bn254/ecntt"
	"github.com/ingonyama-zk/icicle/v3/wrappers/golang/curves/bn254/ntt"
	"github.com/ingonyama-zk/icicle/v3/wrappers/golang/runtime"
)

func Main() {
	// Load backend using env path
	runtime.LoadBackendFromEnvOrDefault()
	// Set Cuda device to perform
	device := runtime.CreateDevice("CUDA", 0)
	runtime.SetDevice(&device)
	// Obtain the default NTT configuration with a predefined coset generator.
	cfg := ntt.GetDefaultNttConfig()

	// Define the size of the input scalars.
	size := 1 << 18

	// Generate Points for the ECNTT operation.
	points := bn254.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[bn254.Projective], size)

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