diff --git a/src/encryptUnified.ts b/src/encryptUnified.ts
index 6a16354..8f93215 100644
--- a/src/encryptUnified.ts
+++ b/src/encryptUnified.ts
@@ -42,9 +42,18 @@ export class Cipher {
       return content;
     }
     if (this.method === "openssl-base64") {
-      return await openssl.encryptArrayBuffer(content, this.password);
+      const res = await openssl.encryptArrayBuffer(content, this.password);
+      if (res === undefined) {
+        throw Error(`cannot encrypt content`);
+      }
+      return res;
     } else if (this.method === "rclone-base64") {
-      return await this.cipherRClone!.encryptContentByCallingWorker(content);
+      const res =
+        await this.cipherRClone!.encryptContentByCallingWorker(content);
+      if (res === undefined) {
+        throw Error(`cannot encrypt content`);
+      }
+      return res;
     } else {
       throw Error(`not supported encrypt method=${this.method}`);
     }
@@ -56,9 +65,18 @@ export class Cipher {
       return content;
     }
     if (this.method === "openssl-base64") {
-      return await openssl.decryptArrayBuffer(content, this.password);
+      const res = await openssl.decryptArrayBuffer(content, this.password);
+      if (res === undefined) {
+        throw Error(`cannot decrypt content`);
+      }
+      return res;
     } else if (this.method === "rclone-base64") {
-      return await this.cipherRClone!.decryptContentByCallingWorker(content);
+      const res =
+        await this.cipherRClone!.decryptContentByCallingWorker(content);
+      if (res === undefined) {
+        throw Error(`cannot decrypt content`);
+      }
+      return res;
     } else {
       throw Error(`not supported decrypt method=${this.method}`);
     }
@@ -70,15 +88,23 @@ export class Cipher {
       return name;
     }
     if (this.method === "openssl-base64") {
-      return await openssl.encryptStringToBase64url(name, this.password);
+      const res = await openssl.encryptStringToBase64url(name, this.password);
+      if (res === undefined) {
+        throw Error(`cannot encrypt name=${name}`);
+      }
+      return res;
     } else if (this.method === "rclone-base64") {
-      return await this.cipherRClone!.encryptNameByCallingWorker(name);
+      const res = await this.cipherRClone!.encryptNameByCallingWorker(name);
+      if (res === undefined) {
+        throw Error(`cannot encrypt name=${name}`);
+      }
+      return res;
     } else {
       throw Error(`not supported encrypt method=${this.method}`);
     }
   }
 
-  async decryptName(name: string) {
+  async decryptName(name: string): Promise<string> {
     // console.debug("start decryptName");
     if (this.password === "") {
       return name;
@@ -88,7 +114,7 @@ export class Cipher {
         // backward compitable with the openssl-base32
         try {
           const res = await openssl.decryptBase32ToString(name, this.password);
-          if (isVaildText(res)) {
+          if (res !== undefined && isVaildText(res)) {
             return res;
           } else {
             throw Error(`cannot decrypt name=${name}`);
@@ -102,7 +128,7 @@ export class Cipher {
             name,
             this.password
           );
-          if (isVaildText(res)) {
+          if (res !== undefined && isVaildText(res)) {
             return res;
           } else {
             throw Error(`cannot decrypt name=${name}`);
@@ -110,9 +136,17 @@ export class Cipher {
         } catch (error) {
           throw Error(`cannot decrypt name=${name}`);
         }
+      } else {
+        throw Error(
+          `method=${this.method} but the name=${name}, likely mismatch`
+        );
       }
     } else if (this.method === "rclone-base64") {
-      return await this.cipherRClone!.decryptNameByCallingWorker(name);
+      const res = await this.cipherRClone!.decryptNameByCallingWorker(name);
+      if (res === undefined) {
+        throw Error(`cannot decrypt name=${name}`);
+      }
+      return res;
     } else {
       throw Error(`not supported decrypt method=${this.method}`);
     }
@@ -136,7 +170,7 @@ export class Cipher {
    * @param name
    * @returns
    */
-  static isLikelyEncryptedName(name: string): boolean {
+  static isLikelyOpenSSLEncryptedName(name: string): boolean {
     if (
       name.startsWith(openssl.MAGIC_ENCRYPTED_PREFIX_BASE32) ||
       name.startsWith(openssl.MAGIC_ENCRYPTED_PREFIX_BASE64URL)
@@ -145,4 +179,37 @@ export class Cipher {
     }
     return false;
   }
+
+  /**
+   * quick guess, no actual decryption here
+   * @param name
+   * @returns
+   */
+  static isLikelyEncryptedName(name: string): boolean {
+    return Cipher.isLikelyOpenSSLEncryptedName(name);
+  }
+
+  /**
+   * quick guess, no actual decryption here, only openssl can be guessed here
+   * @param name
+   * @returns
+   */
+  static isLikelyEncryptedNameNotMatchMethod(
+    name: string,
+    method: CipherMethodType
+  ): boolean {
+    if (
+      Cipher.isLikelyOpenSSLEncryptedName(name) &&
+      method !== "openssl-base64"
+    ) {
+      return true;
+    }
+    if (
+      !Cipher.isLikelyOpenSSLEncryptedName(name) &&
+      method === "openssl-base64"
+    ) {
+      return true;
+    }
+    return false;
+  }
 }
diff --git a/src/misc.ts b/src/misc.ts
index 91208bb..7a169b4 100644
--- a/src/misc.ts
+++ b/src/misc.ts
@@ -165,6 +165,9 @@ export const base64ToBase64url = (a: string, pad: boolean = false) => {
  * @param a
  */
 export const isVaildText = (a: string) => {
+  if (a === undefined) {
+    return false;
+  }
   // If the regex matches, the string is invalid.
   return !XRegExp("\\p{Cc}|\\p{Cf}|\\p{Co}|\\p{Cn}|\\p{Zl}|\\p{Zp}", "A").test(
     a
diff --git a/src/settings.ts b/src/settings.ts
index 6f9c658..48e4809 100644
--- a/src/settings.ts
+++ b/src/settings.ts
@@ -125,15 +125,9 @@ class PasswordModal extends Modal {
 
 class EncryptionMethodModal extends Modal {
   plugin: RemotelySavePlugin;
-  newEncryptionMethod: CipherMethodType;
-  constructor(
-    app: App,
-    plugin: RemotelySavePlugin,
-    newEncryptionMethod: CipherMethodType
-  ) {
+  constructor(app: App, plugin: RemotelySavePlugin) {
     super(app);
     this.plugin = plugin;
-    this.newEncryptionMethod = newEncryptionMethod;
   }
 
   onOpen() {
@@ -153,22 +147,13 @@ class EncryptionMethodModal extends Modal {
         });
       });
 
-    new Setting(contentEl)
-      .addButton((button) => {
-        button.setButtonText(t("confirm"));
-        button.onClick(async () => {
-          this.plugin.settings.encryptionMethod = this.newEncryptionMethod;
-          await this.plugin.saveSettings();
-          this.close();
-        });
-        button.setClass("encryptionmethod-second-confirm");
-      })
-      .addButton((button) => {
-        button.setButtonText(t("goback"));
-        button.onClick(() => {
-          this.close();
-        });
+    new Setting(contentEl).addButton((button) => {
+      button.setButtonText(t("confirm"));
+      button.onClick(async () => {
+        this.close();
       });
+      button.setClass("encryptionmethod-second-confirm");
+    });
   }
 
   onClose() {
@@ -1693,26 +1678,17 @@ export class RemotelySaveSettingTab extends PluginSettingTab {
       .setName(t("settings_encryptionmethod"))
       .setDesc(stringToFragment(t("settings_encryptionmethod_desc")))
       .addDropdown((dropdown) => {
-        dropdown.addOption(
-          "rclone-base64",
-          t("settings_encryptionmethod_rclone")
-        );
-        dropdown.addOption(
-          "openssl-base64",
-          t("settings_encryptionmethod_openssl")
-        );
-        dropdown.onChange(async (val: string) => {
-          if (this.plugin.settings.password === "") {
+        dropdown
+          .addOption("rclone-base64", t("settings_encryptionmethod_rclone"))
+          .addOption("openssl-base64", t("settings_encryptionmethod_openssl"))
+          .setValue(this.plugin.settings.encryptionMethod ?? "rclone-base64")
+          .onChange(async (val: string) => {
             this.plugin.settings.encryptionMethod = val as CipherMethodType;
             await this.plugin.saveSettings();
-          } else {
-            new EncryptionMethodModal(
-              this.app,
-              this.plugin,
-              val as CipherMethodType
-            ).open();
-          }
-        });
+            if (this.plugin.settings.password !== "") {
+              new EncryptionMethodModal(this.app, this.plugin).open();
+            }
+          });
       });
 
     new Setting(basicDiv)
diff --git a/src/sync.ts b/src/sync.ts
index 18e0af3..c3e4bea 100644
--- a/src/sync.ts
+++ b/src/sync.ts
@@ -53,8 +53,9 @@ export interface PasswordCheckType {
     | "unknown_encryption_method"
     | "remote_encrypted_local_no_password"
     | "password_matched"
-    | "password_not_matched_or_remote_not_encrypted"
-    | "likely_no_password_both_sides";
+    | "password_or_method_not_matched_or_remote_not_encrypted"
+    | "likely_no_password_both_sides"
+    | "encryption_method_not_matched";
 }
 
 export const isPasswordOk = async (
@@ -91,8 +92,19 @@ export const isPasswordOk = async (
         reason: "unknown_encryption_method",
       };
     }
+    if (
+      Cipher.isLikelyEncryptedNameNotMatchMethod(santyCheckKey, cipher.method)
+    ) {
+      return {
+        ok: false,
+        reason: "encryption_method_not_matched",
+      };
+    }
     try {
-      await cipher.decryptName(santyCheckKey);
+      const k = await cipher.decryptName(santyCheckKey);
+      if (k === undefined) {
+        throw Error(`decryption failed`);
+      }
       return {
         ok: true,
         reason: "password_matched",
@@ -100,7 +112,7 @@ export const isPasswordOk = async (
     } catch (error) {
       return {
         ok: false,
-        reason: "password_not_matched_or_remote_not_encrypted",
+        reason: "password_or_method_not_matched_or_remote_not_encrypted",
       };
     }
   }