lattigo/ckks の鍵を base64 文字列と相互変換するやつ

main.go

package main

import (
	"encoding/base64"
	"fmt"

	"github.com/tuneinsight/lattigo/v4/ckks"
	"github.com/tuneinsight/lattigo/v4/rlwe"
)

func keyToString(key interface {
	MarshalBinary() ([]byte, error)
}) (string, error) {
	bs, err := key.MarshalBinary()
	if err != nil {
		return "", err
	}
	b64s := base64.StdEncoding.EncodeToString(bs)
	return b64s, nil
}

type rlweKeys = interface {
	rlwe.SecretKey | rlwe.PublicKey | rlwe.RotationKeySet | rlwe.RelinearizationKey
}

func keyFromString[T rlweKeys, PT interface {
	UnmarshalBinary([]byte) error
	*T
}](b64s string) (PT, error) {
	bs, err := base64.StdEncoding.DecodeString(b64s)
	if err != nil {
		return nil, err
	}

	var key T
	err = PT(&key).UnmarshalBinary(bs)
	if err != nil {
		return nil, err
	}

	return &key, nil
}

func main() {
	params, err := ckks.NewParametersFromLiteral(ckks.PN14QP438)
	if err != nil {
		panic(err)
	}

	kgen := ckks.NewKeyGenerator(params)
	sk, pk := kgen.GenKeyPair()

	skEnc, err := keyToString(sk)
	if err != nil {
		panic(err)
	}
	fmt.Println(len(skEnc))
	fmt.Println(keyFromString[rlwe.SecretKey](skEnc))

	pkEnc, err := keyToString(pk)
	if err != nil {
		panic(err)
	}
	fmt.Println(len(pkEnc))
	fmt.Println(keyFromString[rlwe.PublicKey](pkEnc))

	rotations := []int{}
	for i := 1; i < params.N(); i <<= 1 {
		rotations = append(rotations, i)
	}

	rotKey := kgen.GenRotationKeysForRotations(rotations, true, sk)
	rotEnc, err := keyToString(rotKey)
	if err != nil {
		panic(err)
	}
	fmt.Println(len(rotEnc))
	fmt.Println(keyFromString[rlwe.RotationKeySet](rotEnc))

	rlk := kgen.GenRelinearizationKey(sk, 1)
	rlEnc, err := keyToString(rlk)
	if err != nil {
		panic(err)
	}
	fmt.Println(len(rlEnc))
	fmt.Println(keyFromString[rlwe.RelinearizationKey](rlEnc))

}