diff --git a/packages/backend/src/core/AccountUpdateService.ts b/packages/backend/src/core/AccountUpdateService.ts
index fd790913b4..208131ed6e 100644
--- a/packages/backend/src/core/AccountUpdateService.ts
+++ b/packages/backend/src/core/AccountUpdateService.ts
@@ -13,6 +13,7 @@ import { RelayService } from '@/core/RelayService.js';
 import { ApDeliverManagerService } from '@/core/activitypub/ApDeliverManagerService.js';
 import { UserEntityService } from '@/core/entities/UserEntityService.js';
 import { bindThis } from '@/decorators.js';
+import type { PrivateKey } from './activitypub/type.js';
 
 @Injectable()
 export class AccountUpdateService implements OnModuleInit {
@@ -39,7 +40,7 @@ export class AccountUpdateService implements OnModuleInit {
 	 * @param userId ユーザーID
 	 * @param isKeyUpdation Ed25519キーの作成など公開鍵のアップデートによる呼び出しか？ trueにするとメインキーを使うようになる
 	 */
-	public async publishToFollowers(userId: MiUser['id'], isKeyUpdation: boolean = false) {
+	public async publishToFollowers(userId: MiUser['id'], deliverKey?: PrivateKey) {
 		const user = await this.usersRepository.findOneBy({ id: userId });
 		if (user == null) throw new Error('user not found');
 
@@ -47,8 +48,8 @@ export class AccountUpdateService implements OnModuleInit {
 		if (this.userEntityService.isLocalUser(user)) {
 			const content = this.apRendererService.addContext(this.apRendererService.renderUpdate(await this.apRendererService.renderPerson(user), user));
 			await Promise.allSettled([
-				this.apDeliverManagerService.deliverToFollowers(user, content, isKeyUpdation),
-				this.relayService.deliverToRelays(user, content, isKeyUpdation),
+				this.apDeliverManagerService.deliverToFollowers(user, content, deliverKey),
+				this.relayService.deliverToRelays(user, content, deliverKey),
 			]);
 		}
 	}
diff --git a/packages/backend/src/core/QueueService.ts b/packages/backend/src/core/QueueService.ts
index cb5dca2d39..b73d0de4d0 100644
--- a/packages/backend/src/core/QueueService.ts
+++ b/packages/backend/src/core/QueueService.ts
@@ -5,7 +5,7 @@
 
 import { randomUUID } from 'node:crypto';
 import { Inject, Injectable } from '@nestjs/common';
-import type { IActivity } from '@/core/activitypub/type.js';
+import type { IActivity, PrivateKey } from '@/core/activitypub/type.js';
 import type { MiDriveFile } from '@/models/DriveFile.js';
 import type { MiWebhook, webhookEventTypes } from '@/models/Webhook.js';
 import type { Config } from '@/config.js';
@@ -70,7 +70,7 @@ export class QueueService {
 	}
 
 	@bindThis
-	public async deliver(user: ThinUser, content: IActivity | null, to: string | null, isSharedInbox: boolean, forceMainKey?: boolean) {
+	public async deliver(user: ThinUser, content: IActivity | null, to: string | null, isSharedInbox: boolean, privateKey?: PrivateKey) {
 		if (content == null) return null;
 		if (to == null) return null;
 
@@ -84,7 +84,7 @@ export class QueueService {
 			digest: await genRFC3230DigestHeader(contentBody, 'SHA-256'),
 			to,
 			isSharedInbox,
-			forceMainKey,
+			privateKey,
 		};
 
 		return this.deliverQueue.add(to, data, {
@@ -106,7 +106,7 @@ export class QueueService {
 	 * @returns void
 	 */
 	@bindThis
-	public async deliverMany(user: ThinUser, content: IActivity | null, inboxes: Map<string, boolean>, forceMainKey?: boolean) {
+	public async deliverMany(user: ThinUser, content: IActivity | null, inboxes: Map<string, boolean>, privateKey?: PrivateKey) {
 		if (content == null) return null;
 		const contentBody = JSON.stringify(content);
 
@@ -126,7 +126,7 @@ export class QueueService {
 				content: contentBody,
 				to: d[0],
 				isSharedInbox: d[1],
-				forceMainKey,
+				privateKey,
 			} as DeliverJobData,
 			opts,
 		})));
diff --git a/packages/backend/src/core/RelayService.ts b/packages/backend/src/core/RelayService.ts
index 52bf5d8e6a..c5099a5425 100644
--- a/packages/backend/src/core/RelayService.ts
+++ b/packages/backend/src/core/RelayService.ts
@@ -16,6 +16,7 @@ import { ApRendererService } from '@/core/activitypub/ApRendererService.js';
 import { DI } from '@/di-symbols.js';
 import { deepClone } from '@/misc/clone.js';
 import { bindThis } from '@/decorators.js';
+import { PrivateKey } from './activitypub/type.js';
 
 const ACTOR_USERNAME = 'relay.actor' as const;
 
@@ -111,7 +112,7 @@ export class RelayService {
 	}
 
 	@bindThis
-	public async deliverToRelays(user: { id: MiUser['id']; host: null; }, activity: any, forceMainKey?: boolean): Promise<void> {
+	public async deliverToRelays(user: { id: MiUser['id']; host: null; }, activity: any, privateKey?: PrivateKey): Promise<void> {
 		if (activity == null) return;
 
 		const relays = await this.relaysCache.fetch(() => this.relaysRepository.findBy({
@@ -125,7 +126,7 @@ export class RelayService {
 		const signed = await this.apRendererService.attachLdSignature(copy, user);
 
 		for (const relay of relays) {
-			this.queueService.deliver(user, signed, relay.inbox, false, forceMainKey);
+			this.queueService.deliver(user, signed, relay.inbox, false, privateKey);
 		}
 	}
 }
diff --git a/packages/backend/src/core/UserKeypairService.ts b/packages/backend/src/core/UserKeypairService.ts
index 2341976068..26190024cd 100644
--- a/packages/backend/src/core/UserKeypairService.ts
+++ b/packages/backend/src/core/UserKeypairService.ts
@@ -13,6 +13,7 @@ import type { MiUserKeypair } from '@/models/UserKeypair.js';
 import { DI } from '@/di-symbols.js';
 import { bindThis } from '@/decorators.js';
 import { GlobalEventService, GlobalEvents } from '@/core/GlobalEventService.js';
+import { UserEntityService } from '@/core/entities/UserEntityService.js';
 
 @Injectable()
 export class UserKeypairService implements OnApplicationShutdown {
@@ -27,6 +28,7 @@ export class UserKeypairService implements OnApplicationShutdown {
 		private userKeypairsRepository: UserKeypairsRepository,
 
 		private globalEventService: GlobalEventService,
+		private userEntityService: UserEntityService,
 	) {
 		this.cache = new RedisKVCache<MiUserKeypair>(this.redisClient, 'userKeypair', {
 			lifetime: 1000 * 60 * 60 * 24, // 24h
@@ -44,6 +46,35 @@ export class UserKeypairService implements OnApplicationShutdown {
 		return await this.cache.fetch(userId);
 	}
 
+	/**
+	 *
+	 * @param userIdOrHint user id or MiUserKeypair
+	 * @param preferType 'main' or 'ed25519'; If 'ed25519' is specified and ed25519 keypair is not exists, it will return main keypair
+	 * @returns
+	 */
+	@bindThis
+	public async getLocalUserKeypairWithKeyId(
+		userIdOrHint: MiUser['id'] | MiUserKeypair, preferType: 'main' | 'ed25519'
+	): Promise<{ keyId: string; publicKey: string; privateKey: string; }> {
+		const keypair = typeof userIdOrHint === 'string' ? await this.getUserKeypair(userIdOrHint) : userIdOrHint;
+		if (preferType === 'ed25519' && keypair.ed25519PublicKey != null && keypair.ed25519PrivateKey != null) {
+			return {
+				keyId: `${this.userEntityService.genLocalUserUri(keypair.userId)}#ed25519-key`,
+				publicKey: keypair.ed25519PublicKey,
+				privateKey: keypair.ed25519PrivateKey,
+			};
+		}
+		if (preferType === 'main') {
+			return {
+				keyId: `${this.userEntityService.genLocalUserUri(keypair.userId)}#main-key`,
+				publicKey: keypair.publicKey,
+				privateKey: keypair.privateKey,
+			};
+		}
+
+		throw new Error('invalid type');
+	}
+
 	@bindThis
 	public async refresh(userId: MiUser['id']): Promise<void> {
 		return await this.cache.refresh(userId);
@@ -52,14 +83,14 @@ export class UserKeypairService implements OnApplicationShutdown {
 	/**
 	 *
 	 * @param userId user id
-	 * @returns Promise<boolean> true if keypair is created, false if keypair is already exists
+	 * @returns MiUserKeypair if keypair is created, void if keypair is already exists
 	 */
 	@bindThis
-	public async refreshAndprepareEd25519KeyPair(userId: MiUser['id']): Promise<boolean> {
+	public async refreshAndprepareEd25519KeyPair(userId: MiUser['id']): Promise<MiUserKeypair | void> {
 		await this.refresh(userId);
 		const keypair = await this.cache.fetch(userId);
 		if (keypair.ed25519PublicKey != null) {
-			return false;
+			return;
 		}
 
 		const ed25519 = await genEd25519KeyPair();
@@ -68,7 +99,11 @@ export class UserKeypairService implements OnApplicationShutdown {
 			ed25519PrivateKey: ed25519.privateKey,
 		});
 		this.globalEventService.publishInternalEvent('userKeypairUpdated', { userId });
-		return true;
+		return {
+			...keypair,
+			ed25519PublicKey: ed25519.publicKey,
+			ed25519PrivateKey: ed25519.privateKey,
+		};
 	}
 
 	@bindThis
diff --git a/packages/backend/src/core/activitypub/ApDeliverManagerService.ts b/packages/backend/src/core/activitypub/ApDeliverManagerService.ts
index 449524c5ff..7f22f167af 100644
--- a/packages/backend/src/core/activitypub/ApDeliverManagerService.ts
+++ b/packages/backend/src/core/activitypub/ApDeliverManagerService.ts
@@ -10,7 +10,7 @@ import type { FollowingsRepository } from '@/models/_.js';
 import type { MiLocalUser, MiRemoteUser, MiUser } from '@/models/User.js';
 import { QueueService } from '@/core/QueueService.js';
 import { bindThis } from '@/decorators.js';
-import type { IActivity } from '@/core/activitypub/type.js';
+import type { IActivity, PrivateKey } from '@/core/activitypub/type.js';
 import { ThinUser } from '@/queue/types.js';
 import { AccountUpdateService } from '@/core/AccountUpdateService.js';
 import type Logger from '@/logger.js';
@@ -109,17 +109,19 @@ class DeliverManager {
 	 * Execute delivers
 	 */
 	@bindThis
-	public async execute(opts?: { forceMainKey?: boolean }): Promise<void> {
+	public async execute(opts?: { privateKey?: PrivateKey }): Promise<void> {
 		//#region MIGRATION
-		if (opts?.forceMainKey !== true) {
+		if (!opts?.privateKey) {
 			/**
 			 * ed25519の署名がなければ追加する
 			 */
 			const created = await this.userKeypairService.refreshAndprepareEd25519KeyPair(this.actor.id);
 			if (created) {
+				// createdが存在するということは新規作成されたということなので、フォロワーに配信する
 				this.logger.info(`ed25519 key pair created for user ${this.actor.id} and publishing to followers`);
 				// リモートに配信
-				await this.accountUpdateService.publishToFollowers(this.actor.id, true);
+				const keyPair = await this.userKeypairService.getLocalUserKeypairWithKeyId(created, 'ed25519');
+				await this.accountUpdateService.publishToFollowers(this.actor.id, { keyId: keyPair.keyId, privateKeyPem: keyPair.privateKey });
 			}
 		}
 		//#endregion
@@ -163,7 +165,7 @@ class DeliverManager {
 		}
 
 		// deliver
-		await this.queueService.deliverMany(this.actor, this.activity, inboxes);
+		await this.queueService.deliverMany(this.actor, this.activity, inboxes, opts?.privateKey);
 		this.logger.info(`Deliver queues dispatched: inboxes=${inboxes.size} actorId=${this.actor.id} activityId=${this.activity?.id}`);
 	}
 }
@@ -191,7 +193,7 @@ export class ApDeliverManagerService {
 	 * @param forceMainKey Force to use main (rsa) key
 	 */
 	@bindThis
-	public async deliverToFollowers(actor: { id: MiLocalUser['id']; host: null; }, activity: IActivity, forceMainKey?: boolean): Promise<void> {
+	public async deliverToFollowers(actor: { id: MiLocalUser['id']; host: null; }, activity: IActivity, privateKey?: PrivateKey): Promise<void> {
 		const manager = new DeliverManager(
 			this.userKeypairService,
 			this.followingsRepository,
@@ -202,7 +204,7 @@ export class ApDeliverManagerService {
 			activity,
 		);
 		manager.addFollowersRecipe();
-		await manager.execute({ forceMainKey });
+		await manager.execute({ privateKey });
 	}
 
 	/**
diff --git a/packages/backend/src/core/activitypub/ApRequestService.ts b/packages/backend/src/core/activitypub/ApRequestService.ts
index 132593679e..a6b9053706 100644
--- a/packages/backend/src/core/activitypub/ApRequestService.ts
+++ b/packages/backend/src/core/activitypub/ApRequestService.ts
@@ -15,18 +15,7 @@ import { LoggerService } from '@/core/LoggerService.js';
 import { bindThis } from '@/decorators.js';
 import type Logger from '@/logger.js';
 import { validateContentTypeSetAsActivityPub } from '@/core/activitypub/misc/validator.js';
-
-type Signed = {
-	request: Request;
-	signingString: string;
-	signature: string;
-	signatureHeader: string;
-};
-
-type PrivateKey = {
-	privateKeyPem: string;
-	keyId: string;
-};
+import type { PrivateKey } from './type.js';
 
 export async function createSignedPost(args: { level: string; key: PrivateKey; url: string; body: string; digest?: string, additionalHeaders: Record<string, string> }) {
 	const u = new URL(args.url);
@@ -98,21 +87,19 @@ export class ApRequestService {
 	 */
 	@bindThis
 	private async getPrivateKey(userId: MiUser['id'], level: string): Promise<PrivateKey> {
-		const keypair = await this.userKeypairService.getUserKeypair(userId);
+		const type = level === '00' || level === '10' ? 'ed25519' : 'main';
+		const keypair = await this.userKeypairService.getLocalUserKeypairWithKeyId(userId, type);
 
-		return (level !== '00' && level !== '10' && keypair.ed25519PrivateKey) ? {
-			privateKeyPem: keypair.ed25519PrivateKey,
-			keyId: `${this.config.url}/users/${userId}#ed25519-key`,
-		} : {
+		return {
+			keyId: keypair.keyId,
 			privateKeyPem: keypair.privateKey,
-			keyId: `${this.config.url}/users/${userId}#main-key`,
 		};
 	}
 
 	@bindThis
-	public async signedPost(user: { id: MiUser['id'] }, url: string, object: unknown, level: string, digest?: string): Promise<void> {
+	public async signedPost(user: { id: MiUser['id'] }, url: string, object: unknown, level: string, digest?: string, key?: PrivateKey): Promise<void> {
 		const body = typeof object === 'string' ? object : JSON.stringify(object);
-		const key = await this.getPrivateKey(user.id, level);
+		key = key ?? await this.getPrivateKey(user.id, level);
 		const req = await createSignedPost({
 			level,
 			key,
diff --git a/packages/backend/src/core/activitypub/type.ts b/packages/backend/src/core/activitypub/type.ts
index 0b34fd7664..54d1c52dc0 100644
--- a/packages/backend/src/core/activitypub/type.ts
+++ b/packages/backend/src/core/activitypub/type.ts
@@ -326,3 +326,8 @@ export const isAnnounce = (object: IObject): object is IAnnounce => getApType(ob
 export const isBlock = (object: IObject): object is IBlock => getApType(object) === 'Block';
 export const isFlag = (object: IObject): object is IFlag => getApType(object) === 'Flag';
 export const isMove = (object: IObject): object is IMove => getApType(object) === 'Move';
+
+export type PrivateKey = {
+	privateKeyPem: string;
+	keyId: string;
+};
diff --git a/packages/backend/src/queue/processors/DeliverProcessorService.ts b/packages/backend/src/queue/processors/DeliverProcessorService.ts
index 2a4dd5f997..47a69e7622 100644
--- a/packages/backend/src/queue/processors/DeliverProcessorService.ts
+++ b/packages/backend/src/queue/processors/DeliverProcessorService.ts
@@ -76,16 +76,14 @@ export class DeliverProcessorService {
 			await this.fetchInstanceMetadataService.fetchInstanceMetadata(_server).then(() => {});
 			const server = await this.federatedInstanceService.fetch(host);
 
-			/**
-			 * RSAキーを強制するかでレベルを変える
-			 */
-			const level = job.data.forceMainKey ?
-				server.httpMessageSignaturesImplementationLevel === '11' ?
-					'10' :
-					'00'
-				: server.httpMessageSignaturesImplementationLevel;
-
-			await this.apRequestService.signedPost(job.data.user, job.data.to, job.data.content, level, job.data.digest);
+			await this.apRequestService.signedPost(
+				job.data.user,
+				job.data.to,
+				job.data.content,
+				server.httpMessageSignaturesImplementationLevel,
+				job.data.digest,
+				job.data.privateKey,
+			);
 
 			// Update stats
 			if (server.isNotResponding) {
diff --git a/packages/backend/src/queue/types.ts b/packages/backend/src/queue/types.ts
index 74e0c0a66e..12e3136270 100644
--- a/packages/backend/src/queue/types.ts
+++ b/packages/backend/src/queue/types.ts
@@ -8,7 +8,7 @@ import type { MiDriveFile } from '@/models/DriveFile.js';
 import type { MiNote } from '@/models/Note.js';
 import type { MiUser } from '@/models/User.js';
 import type { MiWebhook } from '@/models/Webhook.js';
-import type { IActivity } from '@/core/activitypub/type.js';
+import type { IActivity, PrivateKey } from '@/core/activitypub/type.js';
 import type { ParsedSignature } from '@misskey-dev/node-http-message-signatures';
 
 /**
@@ -39,7 +39,7 @@ export type DeliverJobData = {
 	/** whether it is sharedInbox */
 	isSharedInbox: boolean;
 	/** force to use main (rsa) key */
-	forceMainKey?: boolean;
+	privateKey?: PrivateKey;
 };
 
 export type InboxJobData = {