diff --git a/src/lib/hooks/gotoStateful.ts b/src/lib/hooks/gotoStateful.ts
index 47f1190..2d168a7 100644
--- a/src/lib/hooks/gotoStateful.ts
+++ b/src/lib/hooks/gotoStateful.ts
@@ -10,7 +10,7 @@ interface KeyExportState {
   signKeyBase64: string;
   verifyKeyBase64: string;
 
-  mekDraft: ArrayBuffer;
+  masterKeyWrapped: ArrayBuffer;
 }
 
 const useAutoNull = <T>(value: T | null) => {
diff --git a/src/lib/indexedDB.ts b/src/lib/indexedDB.ts
index 1282314..ff4660b 100644
--- a/src/lib/indexedDB.ts
+++ b/src/lib/indexedDB.ts
@@ -1,26 +1,36 @@
 import { Dexie, type EntityTable } from "dexie";
 
-type RSAKeyUsage = "encrypt" | "decrypt" | "sign" | "verify";
+type ClientKeyUsage = "encrypt" | "decrypt" | "sign" | "verify";
 
-interface RSAKey {
-  usage: RSAKeyUsage;
+interface ClientKey {
+  usage: ClientKeyUsage;
+  key: CryptoKey;
+}
+
+type MasterKeyState = "active" | "retired";
+
+interface MasterKey {
+  version: number;
+  state: MasterKeyState;
   key: CryptoKey;
 }
 
 const keyStore = new Dexie("keyStore") as Dexie & {
-  rsaKey: EntityTable<RSAKey, "usage">;
+  clientKey: EntityTable<ClientKey, "usage">;
+  masterKey: EntityTable<MasterKey, "version">;
 };
 
 keyStore.version(1).stores({
-  rsaKey: "usage",
+  clientKey: "usage",
+  masterKey: "version",
 });
 
-export const getRSAKey = async (usage: RSAKeyUsage) => {
-  const key = await keyStore.rsaKey.get(usage);
+export const getClientKey = async (usage: ClientKeyUsage) => {
+  const key = await keyStore.clientKey.get(usage);
   return key?.key ?? null;
 };
 
-export const storeRSAKey = async (key: CryptoKey, usage: RSAKeyUsage) => {
+export const storeClientKey = async (key: CryptoKey, usage: ClientKeyUsage) => {
   switch (usage) {
     case "encrypt":
     case "verify":
@@ -39,5 +49,16 @@ export const storeRSAKey = async (key: CryptoKey, usage: RSAKeyUsage) => {
       }
       break;
   }
-  await keyStore.rsaKey.put({ usage, key });
+  await keyStore.clientKey.put({ usage, key });
+};
+
+export const getMasterKeys = async () => {
+  return await keyStore.masterKey.toArray();
+};
+
+export const storeMasterKeys = async (keys: MasterKey[]) => {
+  if (keys.some(({ key }) => key.extractable)) {
+    throw new Error("Master keys must be non-extractable");
+  }
+  await keyStore.masterKey.bulkPut(keys);
 };
diff --git a/src/lib/modules/crypto.ts b/src/lib/modules/crypto.ts
index 872265a..8a476d1 100644
--- a/src/lib/modules/crypto.ts
+++ b/src/lib/modules/crypto.ts
@@ -18,7 +18,7 @@ export const generateRSAKeyPair = async (purpose: RSAKeyPurpose) => {
       hash: "SHA-256",
     } satisfies RsaHashedKeyGenParams,
     true,
-    purpose === "encryption" ? ["encrypt", "decrypt"] : ["sign", "verify"],
+    purpose === "encryption" ? ["encrypt", "decrypt", "wrapKey", "unwrapKey"] : ["sign", "verify"],
   );
 };
 
@@ -101,6 +101,33 @@ export const exportAESKey = async (key: CryptoKey) => {
   return await window.crypto.subtle.exportKey("raw", key);
 };
 
+export const wrapAESKeyUsingRSA = async (aesKey: CryptoKey, rsaPublicKey: CryptoKey) => {
+  return await window.crypto.subtle.wrapKey("raw", aesKey, rsaPublicKey, {
+    name: "RSA-OAEP",
+  } satisfies RsaOaepParams);
+};
+
+export const unwrapAESKeyUsingRSA = async (wrappedKey: BufferSource, rsaPrivateKey: CryptoKey) => {
+  return await window.crypto.subtle.unwrapKey(
+    "raw",
+    wrappedKey,
+    rsaPrivateKey,
+    {
+      name: "RSA-OAEP",
+    } satisfies RsaOaepParams,
+    {
+      name: "AES-GCM",
+      length: 256,
+    } satisfies AesKeyGenParams,
+    true,
+    ["encrypt", "decrypt"],
+  );
+};
+
+export const digestSHA256 = async (data: BufferSource) => {
+  return await window.crypto.subtle.digest("SHA-256", data);
+};
+
 export const signRequest = async <T>(data: T, privateKey: CryptoKey) => {
   const dataBuffer = new TextEncoder().encode(JSON.stringify(data));
   const signature = await signRSAMessage(dataBuffer, privateKey);
diff --git a/src/lib/stores/key.ts b/src/lib/stores/key.ts
index 19cff13..7690bbf 100644
--- a/src/lib/stores/key.ts
+++ b/src/lib/stores/key.ts
@@ -7,5 +7,11 @@ export interface ClientKeys {
   verifyKey: CryptoKey;
 }
 
+export interface MasterKey {
+  state: "active" | "retired" | "dead";
+  masterKey: CryptoKey;
+}
+
 export const clientKeyStore = writable<ClientKeys | null>(null);
-export const mekStore = writable<Map<number, CryptoKey>>(new Map());
+
+export const masterKeyStore = writable<Map<number, MasterKey> | null>(null);
diff --git a/src/routes/(fullscreen)/client/pending/+page.svelte b/src/routes/(fullscreen)/client/pending/+page.svelte
new file mode 100644
index 0000000..f362bd5
--- /dev/null
+++ b/src/routes/(fullscreen)/client/pending/+page.svelte
@@ -0,0 +1,64 @@
+<script lang="ts">
+  import { goto } from "$app/navigation";
+  import { TitleDiv } from "$lib/components/divs";
+  import { clientKeyStore, masterKeyStore } from "$lib/stores";
+  import { generateEncryptKeyFingerprint, requestMasterKeyDownload } from "./service";
+
+  import IconFingerprint from "~icons/material-symbols/fingerprint";
+
+  let { data } = $props();
+
+  let fingerprint = $derived(
+    $clientKeyStore ? generateEncryptKeyFingerprint($clientKeyStore.encryptKey) : undefined,
+  );
+
+  $effect(() => {
+    if ($masterKeyStore) {
+      goto(data.redirectPath);
+    } else if ($clientKeyStore) {
+      requestMasterKeyDownload($clientKeyStore.decryptKey).then(async (ok) => {
+        if (ok) {
+          return await goto(data.redirectPath);
+        }
+      });
+    }
+  });
+</script>
+
+<svetle:head>
+  <title>승인을 기다리고 있어요.</title>
+</svetle:head>
+
+<div class="flex h-full flex-col">
+  <TitleDiv>
+    <div class="flex flex-col gap-y-2">
+      <h1 class="text-3xl font-bold">승인을 기다리고 있어요.</h1>
+      <p>
+        회원님의 다른 디바이스에서 이 디바이스의 데이터 접근을 승인해야 서비스를 이용할 수 있어요.
+      </p>
+    </div>
+    <div class="my-4 flex flex-col gap-y-2">
+      <div>
+        <IconFingerprint class="mx-auto text-7xl" />
+        <p class="text-center text-xl font-bold text-primary-500">암호 키 지문</p>
+      </div>
+      <div class="rounded-2xl bg-gray-100 p-4">
+        <p class="text-center text-2xl font-medium text-gray-800">
+          {#if !fingerprint}
+            지문 생성하는 중...
+          {:else}
+            {#await fingerprint}
+              지문 생성하는 중...
+            {:then fingerprint}
+              {fingerprint}
+            {/await}
+          {/if}
+        </p>
+      </div>
+      <p class="text-center">
+        암호 키 지문은 디바이스마다 다르게 생성돼요. <br />
+        지문이 일치하는지 확인 후 승인해 주세요.
+      </p>
+    </div>
+  </TitleDiv>
+</div>
diff --git a/src/routes/(fullscreen)/client/pending/+page.ts b/src/routes/(fullscreen)/client/pending/+page.ts
new file mode 100644
index 0000000..626d2e0
--- /dev/null
+++ b/src/routes/(fullscreen)/client/pending/+page.ts
@@ -0,0 +1,6 @@
+import type { PageLoad } from "./$types";
+
+export const load: PageLoad = async ({ url }) => {
+  const redirectPath = url.searchParams.get("redirect") || "/";
+  return { redirectPath };
+};
diff --git a/src/routes/(fullscreen)/client/pending/service.ts b/src/routes/(fullscreen)/client/pending/service.ts
new file mode 100644
index 0000000..51037b5
--- /dev/null
+++ b/src/routes/(fullscreen)/client/pending/service.ts
@@ -0,0 +1,53 @@
+import { callAPI } from "$lib/hooks";
+import { storeMasterKeys } from "$lib/indexedDB";
+import {
+  decodeFromBase64,
+  exportRSAKey,
+  makeAESKeyNonextractable,
+  unwrapAESKeyUsingRSA,
+  digestSHA256,
+} from "$lib/modules/crypto";
+import { masterKeyStore } from "$lib/stores";
+
+export const generateEncryptKeyFingerprint = async (encryptKey: CryptoKey) => {
+  const { key } = await exportRSAKey(encryptKey);
+  const digest = await digestSHA256(key);
+  return Array.from(new Uint8Array(digest))
+    .map((byte) => byte.toString(16).padStart(2, "0"))
+    .join("")
+    .toUpperCase()
+    .match(/.{1,4}/g)!
+    .join(" ");
+};
+
+export const requestMasterKeyDownload = async (decryptKey: CryptoKey) => {
+  const res = await callAPI("/api/mek/list", { method: "GET" });
+  if (!res.ok) return false;
+
+  const data = await res.json();
+  const { meks: masterKeysWrapped } = data as {
+    meks: {
+      version: number;
+      state: "active" | "retired";
+      mek: string;
+    }[];
+  };
+  const masterKeys = await Promise.all(
+    masterKeysWrapped.map(async ({ version, state, mek: masterKeyWrapped }) => ({
+      version,
+      state,
+      masterKey: await makeAESKeyNonextractable(
+        await unwrapAESKeyUsingRSA(decodeFromBase64(masterKeyWrapped), decryptKey),
+      ),
+    })),
+  );
+
+  await storeMasterKeys(
+    masterKeys.map(({ version, state, masterKey }) => ({ version, state, key: masterKey })),
+  );
+  masterKeyStore.set(
+    new Map(masterKeys.map(({ version, state, masterKey }) => [version, { state, masterKey }])),
+  );
+
+  return true;
+};
diff --git a/src/routes/(fullscreen)/key/export/+page.svelte b/src/routes/(fullscreen)/key/export/+page.svelte
index 553e81c..31d7384 100644
--- a/src/routes/(fullscreen)/key/export/+page.svelte
+++ b/src/routes/(fullscreen)/key/export/+page.svelte
@@ -11,7 +11,7 @@
     requestClientRegistration,
     storeClientKeys,
     requestTokenUpgrade,
-    requestInitialMekRegistration,
+    requestInitialMasterKeyRegistration,
   } from "./service";
 
   import IconKey from "~icons/material-symbols/key";
@@ -72,11 +72,7 @@
         throw new Error("Failed to upgrade token");
 
       if (
-        !(await requestInitialMekRegistration(
-          data.mekDraft,
-          $clientKeyStore.encryptKey,
-          $clientKeyStore.signKey,
-        ))
+        !(await requestInitialMasterKeyRegistration(data.masterKeyWrapped, $clientKeyStore.signKey))
       )
         throw new Error("Failed to register initial MEK");
 
diff --git a/src/routes/(fullscreen)/key/export/service.ts b/src/routes/(fullscreen)/key/export/service.ts
index b26ff61..68c4f60 100644
--- a/src/routes/(fullscreen)/key/export/service.ts
+++ b/src/routes/(fullscreen)/key/export/service.ts
@@ -1,6 +1,6 @@
 import { callAPI } from "$lib/hooks";
-import { storeRSAKey } from "$lib/indexedDB";
-import { encodeToBase64, encryptRSAPlaintext, signRequest } from "$lib/modules/crypto";
+import { storeClientKey } from "$lib/indexedDB";
+import { encodeToBase64, signRequest } from "$lib/modules/crypto";
 import type { ClientKeys } from "$lib/stores";
 
 export { requestTokenUpgrade } from "$lib/services/auth";
@@ -35,18 +35,16 @@ export const exportClientKeys = (
 };
 
 export const storeClientKeys = async (clientKeys: ClientKeys) => {
-  await storeRSAKey(clientKeys.encryptKey, "encrypt");
-  await storeRSAKey(clientKeys.decryptKey, "decrypt");
-  await storeRSAKey(clientKeys.signKey, "sign");
-  await storeRSAKey(clientKeys.verifyKey, "verify");
+  await storeClientKey(clientKeys.encryptKey, "encrypt");
+  await storeClientKey(clientKeys.decryptKey, "decrypt");
+  await storeClientKey(clientKeys.signKey, "sign");
+  await storeClientKey(clientKeys.verifyKey, "verify");
 };
 
-export const requestInitialMekRegistration = async (
-  mekDraft: ArrayBuffer,
-  encryptKey: CryptoKey,
+export const requestInitialMasterKeyRegistration = async (
+  masterKeyWrapped: ArrayBuffer,
   signKey: CryptoKey,
 ) => {
-  const mekDraftEncrypted = await encryptRSAPlaintext(mekDraft, encryptKey);
   const res = await callAPI("/api/mek/register/initial", {
     method: "POST",
     headers: {
@@ -54,7 +52,7 @@ export const requestInitialMekRegistration = async (
     },
     body: await signRequest(
       {
-        mek: encodeToBase64(mekDraftEncrypted),
+        mek: encodeToBase64(masterKeyWrapped),
       },
       signKey,
     ),
diff --git a/src/routes/(fullscreen)/key/generate/+page.svelte b/src/routes/(fullscreen)/key/generate/+page.svelte
index 4d48fa6..8af3b29 100644
--- a/src/routes/(fullscreen)/key/generate/+page.svelte
+++ b/src/routes/(fullscreen)/key/generate/+page.svelte
@@ -5,7 +5,7 @@
   import { gotoStateful } from "$lib/hooks";
   import { clientKeyStore } from "$lib/stores";
   import Order from "./Order.svelte";
-  import { generateClientKeys, generateMekDraft } from "./service";
+  import { generateClientKeys, generateInitialMasterKey } from "./service";
 
   import IconKey from "~icons/material-symbols/key";
 
@@ -34,13 +34,13 @@
   const generate = async () => {
     // TODO: Loading indicator
 
-    const clientKeys = await generateClientKeys();
-    const { mekDraft } = await generateMekDraft();
+    const { encryptKey, ...clientKeys } = await generateClientKeys();
+    const { masterKeyWrapped } = await generateInitialMasterKey(encryptKey);
 
     await gotoStateful("/key/export", {
       ...clientKeys,
       redirectPath: data.redirectPath,
-      mekDraft,
+      masterKeyWrapped,
     });
   };
 
diff --git a/src/routes/(fullscreen)/key/generate/service.ts b/src/routes/(fullscreen)/key/generate/service.ts
index 4e16e63..77c3f6f 100644
--- a/src/routes/(fullscreen)/key/generate/service.ts
+++ b/src/routes/(fullscreen)/key/generate/service.ts
@@ -4,9 +4,9 @@ import {
   exportRSAKeyToBase64,
   generateAESKey,
   makeAESKeyNonextractable,
-  exportAESKey,
+  wrapAESKeyUsingRSA,
 } from "$lib/modules/crypto";
-import { clientKeyStore, mekStore } from "$lib/stores";
+import { clientKeyStore } from "$lib/stores";
 
 export const generateClientKeys = async () => {
   const encKeyPair = await generateRSAKeyPair("encryption");
@@ -20,6 +20,7 @@ export const generateClientKeys = async () => {
   });
 
   return {
+    encryptKey: encKeyPair.publicKey,
     encryptKeyBase64: await exportRSAKeyToBase64(encKeyPair.publicKey),
     decryptKeyBase64: await exportRSAKeyToBase64(encKeyPair.privateKey),
     signKeyBase64: await exportRSAKeyToBase64(sigKeyPair.privateKey),
@@ -27,16 +28,10 @@ export const generateClientKeys = async () => {
   };
 };
 
-export const generateMekDraft = async () => {
-  const mek = await generateAESKey();
-  const mekSecured = await makeAESKeyNonextractable(mek);
-
-  mekStore.update((meks) => {
-    meks.set(0, mekSecured);
-    return meks;
-  });
-
+export const generateInitialMasterKey = async (encryptKey: CryptoKey) => {
+  const masterKey = await generateAESKey();
   return {
-    mekDraft: await exportAESKey(mek),
+    masterKey: await makeAESKeyNonextractable(masterKey),
+    masterKeyWrapped: await wrapAESKeyUsingRSA(masterKey, encryptKey),
   };
 };
diff --git a/src/routes/+layout.svelte b/src/routes/+layout.svelte
index 34d3688..066a4e0 100644
--- a/src/routes/+layout.svelte
+++ b/src/routes/+layout.svelte
@@ -2,18 +2,24 @@
   import { onMount } from "svelte";
   import { goto } from "$app/navigation";
   import "../app.css";
-  import { prepareClientKeyStore } from "./services";
+  import { prepareClientKeyStore, prepareMasterKeyStore } from "./services";
 
   let { children } = $props();
 
-  onMount(() => {
-    prepareClientKeyStore().then(async (ok) => {
-      if (!ok && !["/auth", "/key"].some((path) => location.pathname.startsWith(path))) {
-        await goto(
-          "/key/generate?redirect=" + encodeURIComponent(location.pathname + location.search),
-        );
+  onMount(async () => {
+    const redirect = async (url: string) => {
+      const whitelist = ["/auth", "/key", "/client/pending"];
+      if (!whitelist.some((path) => location.pathname.startsWith(path))) {
+        await goto(`${url}?redirect=${encodeURIComponent(location.pathname + location.search)}`);
       }
-    });
+    };
+
+    if (!(await prepareClientKeyStore())) {
+      return await redirect("/key/generate");
+    }
+    if (!(await prepareMasterKeyStore())) {
+      return await redirect("/client/pending");
+    }
   });
 </script>
 
diff --git a/src/routes/services.ts b/src/routes/services.ts
index bb07c6a..1b5c854 100644
--- a/src/routes/services.ts
+++ b/src/routes/services.ts
@@ -1,11 +1,11 @@
-import { getRSAKey } from "$lib/indexedDB";
-import { clientKeyStore } from "$lib/stores";
+import { getClientKey, getMasterKeys } from "$lib/indexedDB";
+import { clientKeyStore, masterKeyStore } from "$lib/stores";
 
 export const prepareClientKeyStore = async () => {
-  const encryptKey = await getRSAKey("encrypt");
-  const decryptKey = await getRSAKey("decrypt");
-  const signKey = await getRSAKey("sign");
-  const verifyKey = await getRSAKey("verify");
+  const encryptKey = await getClientKey("encrypt");
+  const decryptKey = await getClientKey("decrypt");
+  const signKey = await getClientKey("sign");
+  const verifyKey = await getClientKey("verify");
   if (encryptKey && decryptKey && signKey && verifyKey) {
     clientKeyStore.set({ encryptKey, decryptKey, signKey, verifyKey });
     return true;
@@ -13,3 +13,15 @@ export const prepareClientKeyStore = async () => {
     return false;
   }
 };
+
+export const prepareMasterKeyStore = async () => {
+  const masterKeys = await getMasterKeys();
+  if (masterKeys.length > 0) {
+    masterKeyStore.set(
+      new Map(masterKeys.map(({ version, state, key }) => [version, { state, masterKey: key }])),
+    );
+    return true;
+  } else {
+    return false;
+  }
+};