diff --git a/server/util/aes.ts b/server/util/aes.ts
index 340d974..b0fc740 100644
--- a/server/util/aes.ts
+++ b/server/util/aes.ts
@@ -1,15 +1,9 @@
 import { webcrypto } from "crypto";
 
 const subtle = webcrypto.subtle;
+type BufferSource = ArrayBufferView | ArrayBuffer;
 
-type EncryptedData = {
-    iv: ArrayBuffer;
-    ciphertext: ArrayBuffer; //tag 포함
-}
-
-
-export async function AES_GCM_Encrypt(key: ArrayBuffer, msg: ArrayBuffer, aad?: ArrayBuffer): Promise<EncryptedData> {
-    const iv = webcrypto.getRandomValues(new Uint8Array(12));
+export async function AES_GCM_Encrypt(key: BufferSource, iv: BufferSource, msg: BufferSource, aad?: BufferSource): Promise<ArrayBuffer> {
     const keyObj = await subtle.importKey("raw", key, {
         name: "AES-GCM",
     }, false, ["encrypt"]);
@@ -20,23 +14,20 @@ export async function AES_GCM_Encrypt(key: ArrayBuffer, msg: ArrayBuffer, aad?:
         additionalData: aad
     }, keyObj, msg);
 
-    return {
-        iv,
-        ciphertext
-    }
+    return ciphertext;
 }
 
 
-export async function AES_GCM_Decrypt(key: ArrayBuffer, data: EncryptedData, aad?: ArrayBuffer): Promise<ArrayBuffer> {
+export async function AES_GCM_Decrypt(key: BufferSource, iv: BufferSource, ciphertext: BufferSource, aad?: BufferSource): Promise<ArrayBuffer> {
     const keyObj = await subtle.importKey("raw", key, {
         name: "AES-GCM",
     }, false, ["decrypt"]);
 
     const plaintext = await subtle.decrypt({
         name: "AES-GCM",
-        iv: data.iv,
+        iv: iv,
         additionalData: aad
-    }, keyObj, data.ciphertext);
+    }, keyObj, ciphertext);
     //아마도 tag 검증 실패시 예외가 발생할 것으로 예상
 
     return plaintext;