diff --git a/Cargo.lock b/Cargo.lock
index 97e423e..368394c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -536,6 +536,7 @@ name = "demo"
 version = "0.1.0"
 dependencies = [
  "base64 0.22.1",
+ "ring",
  "serde",
  "serde_json",
  "tauri",
@@ -2216,6 +2217,21 @@ dependencies = [
  "windows 0.37.0",
 ]
 
+[[package]]
+name = "ring"
+version = "0.17.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c17fa4cb658e3583423e915b9f3acc01cceaee1860e33d59ebae66adc3a2dc0d"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "getrandom 0.2.15",
+ "libc",
+ "spin",
+ "untrusted",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.24"
@@ -2502,6 +2518,12 @@ dependencies = [
  "system-deps 5.0.0",
 ]
 
+[[package]]
+name = "spin"
+version = "0.9.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
+
 [[package]]
 name = "stable_deref_trait"
 version = "1.2.0"
@@ -3143,6 +3165,12 @@ version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f6ccf251212114b54433ec949fd6a7841275f9ada20dddd2f29e9ceea4501493"
 
+[[package]]
+name = "untrusted"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
+
 [[package]]
 name = "url"
 version = "2.5.2"
diff --git a/packages/demo/src-tauri/Cargo.toml b/packages/demo/src-tauri/Cargo.toml
index 7cbb65f..1a8bf8b 100644
--- a/packages/demo/src-tauri/Cargo.toml
+++ b/packages/demo/src-tauri/Cargo.toml
@@ -11,7 +11,8 @@ edition = "2021"
 tauri-build = { version = "1", features = [] }
 
 [dependencies]
-tauri = { version = "1", features = [ "dialog-all",
+tauri = { version = "1", features = [
+  "dialog-all",
   "fs-exists",
   "fs-read-dir",
   "fs-create-dir",
@@ -24,6 +25,8 @@ tauri = { version = "1", features = [ "dialog-all",
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 base64 = "0.22.1"
+ring = "0.17.8"
+
 
 [dev-dependencies]
 tempfile = "3.3"
diff --git a/packages/demo/src-tauri/src/as_crypt.rs b/packages/demo/src-tauri/src/as_crypt.rs
new file mode 100644
index 0000000..177839b
--- /dev/null
+++ b/packages/demo/src-tauri/src/as_crypt.rs
@@ -0,0 +1,58 @@
+use base64::{engine::general_purpose::STANDARD, Engine as _};
+
+pub fn encrypt(text: &str, key: &str) -> String {
+    let mut result = Vec::new();
+
+    // Convert the key to bytes
+    let key_bytes = key.as_bytes();
+
+    // Convert the plaintext to bytes
+    let text_bytes = text.as_bytes();
+
+    for (i, byte) in text_bytes.iter().enumerate() {
+        let key_byte = key_bytes[i % key_bytes.len()];
+        // XOR the byte with the corresponding byte from the key
+        let encrypted_byte = byte ^ key_byte;
+        result.push(encrypted_byte);
+    }
+
+    STANDARD.encode(&result) // Encode the result as Base64
+}
+
+pub fn decrypt(encrypted_text: &str, key: &str) -> Result<String, &'static str> {
+    // Decode the Base64 encoded string
+    let encrypted = STANDARD
+        .decode(encrypted_text)
+        .map_err(|_| "Base64 decode failed.")?;
+
+    let mut result = Vec::new();
+
+    // Convert the key to bytes
+    let key_bytes = key.as_bytes();
+
+    for (i, byte) in encrypted.iter().enumerate() {
+        let key_byte = key_bytes[i % key_bytes.len()];
+        // XOR the byte with the corresponding byte from the key
+        let decrypted_byte = byte ^ key_byte;
+        result.push(decrypted_byte);
+    }
+
+    // Convert the decrypted bytes back to a String
+    String::from_utf8(result).map_err(|_| "Invalid UTF-8 sequence.")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_crypto() {
+        let key = "secret";
+        let plaintext = "{\"script\":{\"entry\":\"main.mrs\",\"line\":49},\"background\":\"bg.png\",\"music\":{\"name\":\"1.mp3\",\"seconds\":47.46133333333333},\"characters\":[{\"identity\":\"soi\",\"name\":\"诗织\",\"figure\":\"/images/figure/shiori_shy.png\",\"position\":{\"type\":\"auto\",\"order\":1}},{\"identity\":\"self\",\"name\":\"“我”?\"},{\"identity\":\"author\",\"name\":\"夏叶的师傅\"}],\"speaker\":\"诗织\",\"values\":{\"constant\":{\"soi\":\"shiori.png\",\"soiL\":\"shiori_low.png\",\"soiM\":\"shiori_mid.png\",\"soiC\":\"shiori_close.png\",\"soiCS\":\"shiori_close_smile.png\",\"soiS\":\"shiori_smile.png\",\"soiO\":\"shiori_open.png\",\"soiOL\":\"shiori_open_low.png\",\"soiSh\":\"shiori_shy.png\",\"soiSq\":\"shiori_squint.png\"},\"variables\":{\"score\":50}}}\'";
+
+        let encrypted = encrypt(plaintext, key);
+        let decrypted = decrypt(&encrypted, key).expect("Decryption failed.");
+
+        assert_eq!(decrypted, plaintext);
+    }
+}
diff --git a/packages/demo/src-tauri/src/levels.rs b/packages/demo/src-tauri/src/levels.rs
index 3210da5..8f0019d 100644
--- a/packages/demo/src-tauri/src/levels.rs
+++ b/packages/demo/src-tauri/src/levels.rs
@@ -1,3 +1,4 @@
+use crate::as_crypt;
 use base64::{engine::general_purpose::STANDARD, Engine as _};
 use std::collections::HashMap;
 use std::env;
@@ -5,6 +6,8 @@ use std::fs::{self, File};
 use std::io::{self, Read, Write};
 use std::path::PathBuf;
 
+const LEVELS_CRYPTO_KEY: &str = "きみがこの世界に生まれてきてくれて、本当に、よかった";
+
 struct MisakuraDirectory {
     base_directory: PathBuf,
     levels_directory: PathBuf,
@@ -54,7 +57,7 @@ pub fn set_levels(name: &str, png_data: &str, dat_content: &str) -> Result<Strin
 
     let mut dat_file = File::create(&dat_path).map_err(|e| e.to_string())?;
     dat_file
-        .write_all(dat_content.as_bytes())
+        .write_all(as_crypt::encrypt(dat_content, LEVELS_CRYPTO_KEY).as_bytes())
         .map_err(|e| e.to_string())?;
 
     Ok("".to_string())
@@ -86,7 +89,11 @@ pub fn get_all_levels() -> Result<Vec<(String, String, String)>, String> {
                     let mut contents = String::new();
                     file.read_to_string(&mut contents)
                         .map_err(|e| e.to_string())?;
-                    dat_files.insert(file_stem, contents);
+                    dat_files.insert(
+                        file_stem,
+                        as_crypt::decrypt(contents.as_str(), LEVELS_CRYPTO_KEY)
+                            .map_err(|e| e.to_string())?,
+                    );
                 }
             }
         }
diff --git a/packages/demo/src-tauri/src/main.rs b/packages/demo/src-tauri/src/main.rs
index 9b032b9..8dac8e1 100644
--- a/packages/demo/src-tauri/src/main.rs
+++ b/packages/demo/src-tauri/src/main.rs
@@ -1,5 +1,6 @@
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
+mod as_crypt;
 mod levels;
 
 use levels::{get_all_levels, get_base_directory, set_levels};
diff --git a/packages/misakura/src/class/levels/FileAdapter.ts b/packages/misakura/src/class/levels/FileAdapter.ts
index 142c22b..0e424c2 100644
--- a/packages/misakura/src/class/levels/FileAdapter.ts
+++ b/packages/misakura/src/class/levels/FileAdapter.ts
@@ -2,17 +2,25 @@ import { none } from '@kotori-bot/core'
 import LevelsAdapter from './LevelsAdapter'
 import type { LevelsData } from './LevelsAdapter'
 import { invoke } from '@tauri-apps/api'
+import { logger } from '../../tools/logger'
 
 export class FileAdapter extends LevelsAdapter {
   public async getAll() {
     return ((await invoke('get_all_levels')) as [string, string, string][])
       .map(([name, pngData, datContent]) => {
         const key = Number(name)
-        if (Number.isNaN(key)) return null
-        if (!pngData) return null
+        if (Number.isNaN(key)) {
+          logger.warn(`Invalid level name: ${name}`)
+          return null
+        }
+        if (!pngData) {
+          logger.warn(`Level ${name} has no icon data`)
+          return null
+        }
         try {
           return { ...JSON.parse(datContent), icon: pngData, position: key }
         } catch {
+          logger.warn(`Level ${name} has invalid data: ${datContent}`)
           return null
         }
       })