diff --git a/src/backend/database/database.ts b/src/backend/database/database.ts
index 7a2111de..2f2dc20b 100644
--- a/src/backend/database/database.ts
+++ b/src/backend/database/database.ts
@@ -576,19 +576,30 @@ app.post("/database/export", authenticateJWT, async (req, res) => {
         );
       `);
 
-      // Export current user only (exclude sensitive fields like password_hash)
+      // Export current user only (replace sensitive password_hash with placeholder)
       const userRecord = user[0];
       const insertUser = exportDb.prepare(`
-        INSERT INTO users (id, username, is_admin, is_oidc, oidc_identifier, totp_enabled)
-        VALUES (?, ?, ?, ?, ?, ?)
+        INSERT INTO users (id, username, password_hash, is_admin, is_oidc, oidc_identifier, client_id, client_secret, issuer_url, authorization_url, token_url, identifier_path, name_path, scopes, totp_secret, totp_enabled, totp_backup_codes)
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
       `);
       insertUser.run(
         userRecord.id,
         userRecord.username,
+        "[EXPORTED_USER_NO_PASSWORD]", // Replace password hash with placeholder
         userRecord.is_admin ? 1 : 0,
         userRecord.is_oidc ? 1 : 0,
         userRecord.oidc_identifier || null,
-        userRecord.totp_enabled ? 1 : 0
+        userRecord.client_id || null,
+        userRecord.client_secret || null,
+        userRecord.issuer_url || null,
+        userRecord.authorization_url || null,
+        userRecord.token_url || null,
+        userRecord.identifier_path || null,
+        userRecord.name_path || null,
+        userRecord.scopes || null,
+        userRecord.totp_secret || null,
+        userRecord.totp_enabled ? 1 : 0,
+        userRecord.totp_backup_codes || null
       );
 
       // Export SSH hosts (decrypted)
@@ -894,7 +905,7 @@ app.post("/database/import", authenticateJWT, upload.single("file"), async (req,
               autostartPassword: host.autostart_password,
               autostartKey: host.autostart_key,
               autostartKeyPassword: host.autostart_key_password,
-              credentialId: host.credential_id,
+              credentialId: null, // Reset credential references during import - user can reassign
               enableTerminal: Boolean(host.enable_terminal),
               enableTunnel: Boolean(host.enable_tunnel),
               tunnelConnections: host.tunnel_connections,
diff --git a/src/backend/database/db/old-index.ts.bak b/src/backend/database/db/old-index.ts.bak
new file mode 100644
index 00000000..7098d0b4
--- /dev/null
+++ b/src/backend/database/db/old-index.ts.bak
@@ -0,0 +1,600 @@
+import { drizzle } from "drizzle-orm/better-sqlite3";
+import Database from "better-sqlite3";
+import * as schema from "./schema.js";
+import { databaseLogger } from "../../utils/logger.js";
+import { UserDatabaseManager } from "../../utils/user-database-manager.js";
+
+// Global database manager instance
+const databaseManager = UserDatabaseManager.getInstance();
+
+/**
+ * Initialize database system - simplified for user-based architecture
+ */
+async function initializeDatabase(): Promise<void> {
+  try {
+    databaseLogger.info("Initializing database system (user-based architecture)", {
+      operation: "db_init_v3",
+    });
+
+    // Initialize system database (unencrypted)
+    await databaseManager.initializeSystem();
+
+    databaseLogger.success("Database system initialized successfully", {
+      operation: "db_init_v3_success",
+    });
+
+  } catch (error) {
+    databaseLogger.error("Failed to initialize database system", error, {
+      operation: "db_init_v3_failed",
+    });
+    throw error;
+  }
+}
+
+// Export a promise that resolves when database is fully initialized
+export const databaseReady = initializeDatabase()
+  .then(() => {
+    databaseLogger.success("Database system ready", {
+      operation: "db_ready",
+      architecture: "v3-user-based",
+    });
+  })
+  .catch((error) => {
+    databaseLogger.error("Failed to initialize database system", error, {
+      operation: "db_ready_failed",
+    });
+    process.exit(1);
+  });
+
+  databaseLogger.info(`Initializing SQLite database`, {
+    operation: "db_init",
+    path: actualDbPath,
+    encrypted:
+      enableFileEncryption &&
+      DatabaseFileEncryption.isEncryptedDatabaseFile(encryptedDbPath),
+    inMemory: true,
+    isNewDatabase,
+  });
+
+  // Create module-level sqlite instance after database is initialized
+  sqlite = memoryDatabase;
+
+  // Initialize drizzle ORM with the configured database
+  db = drizzle(sqlite, { schema });
+
+  databaseLogger.info("Database ORM initialized", {
+    operation: "drizzle_init",
+    tablesConfigured: Object.keys(schema).length
+  });
+
+  sqlite.exec(`
+    CREATE TABLE IF NOT EXISTS users (
+        id TEXT PRIMARY KEY,
+        username TEXT NOT NULL,
+        password_hash TEXT NOT NULL,
+        is_admin INTEGER NOT NULL DEFAULT 0,
+        is_oidc INTEGER NOT NULL DEFAULT 0,
+        client_id TEXT NOT NULL,
+        client_secret TEXT NOT NULL,
+        issuer_url TEXT NOT NULL,
+        authorization_url TEXT NOT NULL,
+        token_url TEXT NOT NULL,
+        redirect_uri TEXT,
+        identifier_path TEXT NOT NULL,
+        name_path TEXT NOT NULL,
+        scopes TEXT NOT NULL
+    );
+
+    CREATE TABLE IF NOT EXISTS settings (
+        key TEXT PRIMARY KEY,
+        value TEXT NOT NULL
+    );
+
+    CREATE TABLE IF NOT EXISTS ssh_data (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id TEXT NOT NULL,
+        name TEXT,
+        ip TEXT NOT NULL,
+        port INTEGER NOT NULL,
+        username TEXT NOT NULL,
+        folder TEXT,
+        tags TEXT,
+        pin INTEGER NOT NULL DEFAULT 0,
+        auth_type TEXT NOT NULL,
+        password TEXT,
+        key TEXT,
+        key_password TEXT,
+        key_type TEXT,
+        enable_terminal INTEGER NOT NULL DEFAULT 1,
+        enable_tunnel INTEGER NOT NULL DEFAULT 1,
+        tunnel_connections TEXT,
+        enable_file_manager INTEGER NOT NULL DEFAULT 1,
+        default_path TEXT,
+        created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (user_id) REFERENCES users (id)
+    );
+
+    CREATE TABLE IF NOT EXISTS file_manager_recent (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id TEXT NOT NULL,
+        host_id INTEGER NOT NULL,
+        name TEXT NOT NULL,
+        path TEXT NOT NULL,
+        last_opened TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (user_id) REFERENCES users (id),
+        FOREIGN KEY (host_id) REFERENCES ssh_data (id)
+    );
+
+    CREATE TABLE IF NOT EXISTS file_manager_pinned (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id TEXT NOT NULL,
+        host_id INTEGER NOT NULL,
+        name TEXT NOT NULL,
+        path TEXT NOT NULL,
+        pinned_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (user_id) REFERENCES users (id),
+        FOREIGN KEY (host_id) REFERENCES ssh_data (id)
+    );
+
+    CREATE TABLE IF NOT EXISTS file_manager_shortcuts (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id TEXT NOT NULL,
+        host_id INTEGER NOT NULL,
+        name TEXT NOT NULL,
+        path TEXT NOT NULL,
+        created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (user_id) REFERENCES users (id),
+        FOREIGN KEY (host_id) REFERENCES ssh_data (id)
+    );
+
+    CREATE TABLE IF NOT EXISTS dismissed_alerts (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id TEXT NOT NULL,
+        alert_id TEXT NOT NULL,
+        dismissed_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (user_id) REFERENCES users (id)
+    );
+
+    CREATE TABLE IF NOT EXISTS ssh_credentials (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id TEXT NOT NULL,
+        name TEXT NOT NULL,
+        description TEXT,
+        folder TEXT,
+        tags TEXT,
+        auth_type TEXT NOT NULL,
+        username TEXT NOT NULL,
+        password TEXT,
+        key TEXT,
+        key_password TEXT,
+        key_type TEXT,
+        usage_count INTEGER NOT NULL DEFAULT 0,
+        last_used TEXT,
+        created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (user_id) REFERENCES users (id)
+    );
+
+    CREATE TABLE IF NOT EXISTS ssh_credential_usage (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        credential_id INTEGER NOT NULL,
+        host_id INTEGER NOT NULL,
+        user_id TEXT NOT NULL,
+        used_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (credential_id) REFERENCES ssh_credentials (id),
+        FOREIGN KEY (host_id) REFERENCES ssh_data (id),
+        FOREIGN KEY (user_id) REFERENCES users (id)
+    );
+`);
+
+  // Run schema migrations
+  migrateSchema();
+
+  // Initialize default settings
+  try {
+    const row = sqlite
+      .prepare("SELECT value FROM settings WHERE key = 'allow_registration'")
+      .get();
+    if (!row) {
+      databaseLogger.info("Initializing default settings", {
+        operation: "db_init",
+        setting: "allow_registration",
+      });
+      sqlite
+        .prepare(
+          "INSERT INTO settings (key, value) VALUES ('allow_registration', 'true')",
+        )
+        .run();
+    }
+  } catch (e) {
+    databaseLogger.warn("Could not initialize default settings", {
+      operation: "db_init",
+      error: e,
+    });
+  }
+}
+
+const addColumnIfNotExists = (
+  table: string,
+  column: string,
+  definition: string,
+) => {
+  try {
+    sqlite
+      .prepare(
+        `SELECT ${column}
+                        FROM ${table} LIMIT 1`,
+      )
+      .get();
+  } catch (e) {
+    try {
+      databaseLogger.debug(`Adding column ${column} to ${table}`, {
+        operation: "schema_migration",
+        table,
+        column,
+      });
+      sqlite.exec(`ALTER TABLE ${table}
+                ADD COLUMN ${column} ${definition};`);
+      databaseLogger.success(`Column ${column} added to ${table}`, {
+        operation: "schema_migration",
+        table,
+        column,
+      });
+    } catch (alterError) {
+      databaseLogger.warn(`Failed to add column ${column} to ${table}`, {
+        operation: "schema_migration",
+        table,
+        column,
+        error: alterError,
+      });
+    }
+  }
+};
+
+const migrateSchema = () => {
+  databaseLogger.info("Checking for schema updates...", {
+    operation: "schema_migration",
+  });
+
+  addColumnIfNotExists("users", "is_admin", "INTEGER NOT NULL DEFAULT 0");
+
+  addColumnIfNotExists("users", "is_oidc", "INTEGER NOT NULL DEFAULT 0");
+  addColumnIfNotExists("users", "oidc_identifier", "TEXT");
+  addColumnIfNotExists("users", "client_id", "TEXT");
+  addColumnIfNotExists("users", "client_secret", "TEXT");
+  addColumnIfNotExists("users", "issuer_url", "TEXT");
+  addColumnIfNotExists("users", "authorization_url", "TEXT");
+  addColumnIfNotExists("users", "token_url", "TEXT");
+
+  addColumnIfNotExists("users", "identifier_path", "TEXT");
+  addColumnIfNotExists("users", "name_path", "TEXT");
+  addColumnIfNotExists("users", "scopes", "TEXT");
+
+  addColumnIfNotExists("users", "totp_secret", "TEXT");
+  addColumnIfNotExists("users", "totp_enabled", "INTEGER NOT NULL DEFAULT 0");
+  addColumnIfNotExists("users", "totp_backup_codes", "TEXT");
+
+  addColumnIfNotExists("ssh_data", "name", "TEXT");
+  addColumnIfNotExists("ssh_data", "folder", "TEXT");
+  addColumnIfNotExists("ssh_data", "tags", "TEXT");
+  addColumnIfNotExists("ssh_data", "pin", "INTEGER NOT NULL DEFAULT 0");
+  addColumnIfNotExists(
+    "ssh_data",
+    "auth_type",
+    'TEXT NOT NULL DEFAULT "password"',
+  );
+  addColumnIfNotExists("ssh_data", "password", "TEXT");
+  addColumnIfNotExists("ssh_data", "key", "TEXT");
+  addColumnIfNotExists("ssh_data", "key_password", "TEXT");
+  addColumnIfNotExists("ssh_data", "key_type", "TEXT");
+  addColumnIfNotExists(
+    "ssh_data",
+    "enable_terminal",
+    "INTEGER NOT NULL DEFAULT 1",
+  );
+  addColumnIfNotExists(
+    "ssh_data",
+    "enable_tunnel",
+    "INTEGER NOT NULL DEFAULT 1",
+  );
+  addColumnIfNotExists("ssh_data", "tunnel_connections", "TEXT");
+  addColumnIfNotExists(
+    "ssh_data",
+    "enable_file_manager",
+    "INTEGER NOT NULL DEFAULT 1",
+  );
+  addColumnIfNotExists("ssh_data", "default_path", "TEXT");
+  addColumnIfNotExists(
+    "ssh_data",
+    "created_at",
+    "TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP",
+  );
+  addColumnIfNotExists(
+    "ssh_data",
+    "updated_at",
+    "TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP",
+  );
+
+  addColumnIfNotExists(
+    "ssh_data",
+    "credential_id",
+    "INTEGER REFERENCES ssh_credentials(id)",
+  );
+
+
+  // SSH credentials table migrations for encryption support
+  addColumnIfNotExists("ssh_credentials", "private_key", "TEXT");
+  addColumnIfNotExists("ssh_credentials", "public_key", "TEXT");
+  addColumnIfNotExists("ssh_credentials", "detected_key_type", "TEXT");
+
+  addColumnIfNotExists("file_manager_recent", "host_id", "INTEGER NOT NULL");
+  addColumnIfNotExists("file_manager_pinned", "host_id", "INTEGER NOT NULL");
+  addColumnIfNotExists("file_manager_shortcuts", "host_id", "INTEGER NOT NULL");
+
+  databaseLogger.success("Schema migration completed", {
+    operation: "schema_migration",
+  });
+};
+
+// Function to save in-memory database to encrypted file
+async function saveMemoryDatabaseToFile() {
+  if (!memoryDatabase || !enableFileEncryption) return;
+
+  try {
+    // Export in-memory database to buffer
+    const buffer = memoryDatabase.serialize();
+
+    // Encrypt and save to file (now async)
+    await DatabaseFileEncryption.encryptDatabaseFromBuffer(buffer, encryptedDbPath);
+
+    databaseLogger.debug("In-memory database saved to encrypted file", {
+      operation: "memory_db_save",
+      bufferSize: buffer.length,
+      encryptedPath: encryptedDbPath,
+    });
+  } catch (error) {
+    databaseLogger.error("Failed to save in-memory database", error, {
+      operation: "memory_db_save_failed",
+    });
+  }
+}
+
+// Function to handle post-initialization file encryption and cleanup
+async function handlePostInitFileEncryption() {
+  if (!enableFileEncryption) return;
+
+  try {
+    // Clean up any existing unencrypted database files
+    if (fs.existsSync(dbPath)) {
+      databaseLogger.warn(
+        "Found unencrypted database file, removing for security",
+        {
+          operation: "db_security_cleanup_existing",
+          removingPath: dbPath,
+        },
+      );
+
+      try {
+        fs.unlinkSync(dbPath);
+        databaseLogger.success(
+          "Unencrypted database file removed for security",
+          {
+            operation: "db_security_cleanup_complete",
+            removedPath: dbPath,
+          },
+        );
+      } catch (error) {
+        databaseLogger.warn(
+          "Could not remove unencrypted database file (may be locked)",
+          {
+            operation: "db_security_cleanup_deferred",
+            path: dbPath,
+            error: error instanceof Error ? error.message : "Unknown error",
+          },
+        );
+
+        // Try again after a short delay
+        setTimeout(() => {
+          try {
+            if (fs.existsSync(dbPath)) {
+              fs.unlinkSync(dbPath);
+              databaseLogger.success(
+                "Delayed cleanup: unencrypted database file removed",
+                {
+                  operation: "db_security_cleanup_delayed_success",
+                  removedPath: dbPath,
+                },
+              );
+            }
+          } catch (delayedError) {
+            databaseLogger.error(
+              "Failed to remove unencrypted database file even after delay",
+              delayedError,
+              {
+                operation: "db_security_cleanup_delayed_failed",
+                path: dbPath,
+              },
+            );
+          }
+        }, 2000);
+      }
+    }
+
+    // Always save the in-memory database (whether new or existing)
+    if (memoryDatabase) {
+      // Save immediately after initialization
+      await saveMemoryDatabaseToFile();
+
+      // Set up periodic saves every 5 minutes
+      setInterval(saveMemoryDatabaseToFile, 5 * 60 * 1000);
+    }
+  } catch (error) {
+    databaseLogger.error(
+      "Failed to handle database file encryption/cleanup",
+      error,
+      {
+        operation: "db_encrypt_cleanup_failed",
+      },
+    );
+
+    // Don't fail the entire initialization for this
+  }
+}
+
+// Export a promise that resolves when database is fully initialized
+export const databaseReady = initializeCompleteDatabase()
+  .then(async () => {
+    await handlePostInitFileEncryption();
+
+    databaseLogger.success("Database connection established", {
+      operation: "db_init",
+      path: actualDbPath,
+      hasEncryptedBackup:
+        enableFileEncryption &&
+        DatabaseFileEncryption.isEncryptedDatabaseFile(encryptedDbPath),
+    });
+  })
+  .catch((error) => {
+    databaseLogger.error("Failed to initialize database", error, {
+      operation: "db_init",
+    });
+    process.exit(1);
+  });
+
+// Cleanup function for database and temporary files
+async function cleanupDatabase() {
+  // Save in-memory database before closing
+  if (memoryDatabase) {
+    try {
+      await saveMemoryDatabaseToFile();
+    } catch (error) {
+      databaseLogger.error(
+        "Failed to save in-memory database before shutdown",
+        error,
+        {
+          operation: "shutdown_save_failed",
+        },
+      );
+    }
+  }
+
+  // Close database connection
+  try {
+    if (sqlite) {
+      sqlite.close();
+      databaseLogger.debug("Database connection closed", {
+        operation: "db_close",
+      });
+    }
+  } catch (error) {
+    databaseLogger.warn("Error closing database connection", {
+      operation: "db_close_error",
+      error: error instanceof Error ? error.message : "Unknown error",
+    });
+  }
+
+  // Clean up temp directory
+  try {
+    const tempDir = path.join(dataDir, ".temp");
+    if (fs.existsSync(tempDir)) {
+      const files = fs.readdirSync(tempDir);
+      for (const file of files) {
+        try {
+          fs.unlinkSync(path.join(tempDir, file));
+        } catch {
+          // Ignore individual file cleanup errors
+        }
+      }
+
+      try {
+        fs.rmdirSync(tempDir);
+        databaseLogger.debug("Temp directory cleaned up", {
+          operation: "temp_dir_cleanup",
+        });
+      } catch {
+        // Ignore directory removal errors
+      }
+    }
+  } catch (error) {
+    // Ignore temp directory cleanup errors
+  }
+}
+
+// Register cleanup handlers
+process.on("exit", () => {
+  // Synchronous cleanup only for exit event
+  if (sqlite) {
+    try {
+      sqlite.close();
+    } catch {}
+  }
+});
+
+process.on("SIGINT", async () => {
+  databaseLogger.info("Received SIGINT, cleaning up...", {
+    operation: "shutdown",
+  });
+  await cleanupDatabase();
+  process.exit(0);
+});
+
+process.on("SIGTERM", async () => {
+  databaseLogger.info("Received SIGTERM, cleaning up...", {
+    operation: "shutdown",
+  });
+  await cleanupDatabase();
+  process.exit(0);
+});
+
+// Database connection - will be initialized after database setup
+let db: ReturnType<typeof drizzle<typeof schema>>;
+
+// Export database connection getter function to avoid undefined access
+export function getDb(): ReturnType<typeof drizzle<typeof schema>> {
+  if (!db) {
+    throw new Error("Database not initialized. Ensure databaseReady promise is awaited before accessing db.");
+  }
+  return db;
+}
+
+// Legacy export for compatibility - will throw if accessed before initialization
+export { db };
+export { DatabaseFileEncryption };
+export const databasePaths = {
+  main: actualDbPath,
+  encrypted: encryptedDbPath,
+  directory: dbDir,
+  inMemory: true,
+};
+
+// Memory database buffer function
+function getMemoryDatabaseBuffer(): Buffer {
+  if (!memoryDatabase) {
+    throw new Error("Memory database not initialized");
+  }
+
+  try {
+    // Export in-memory database to buffer
+    const buffer = memoryDatabase.serialize();
+
+    databaseLogger.debug("Memory database serialized to buffer", {
+      operation: "memory_db_serialize",
+      bufferSize: buffer.length,
+    });
+
+    return buffer;
+  } catch (error) {
+    databaseLogger.error(
+      "Failed to serialize memory database to buffer",
+      error,
+      {
+        operation: "memory_db_serialize_failed",
+      },
+    );
+    throw error;
+  }
+}
+
+// Export save function for manual saves and buffer access
+export { saveMemoryDatabaseToFile, getMemoryDatabaseBuffer };
diff --git a/src/locales/en/translation.json b/src/locales/en/translation.json
index 4068b963..ff979b5a 100644
--- a/src/locales/en/translation.json
+++ b/src/locales/en/translation.json
@@ -488,7 +488,11 @@
     "createBackup": "Create Backup",
     "exportImport": "Export/Import",
     "export": "Export",
-    "import": "Import"
+    "import": "Import",
+    "passwordRequired": "Password required",
+    "confirmExport": "Confirm Export",
+    "exportDescription": "Export SSH hosts and credentials as SQLite file",
+    "importDescription": "Import SQLite file with incremental merge (skips duplicates)"
   },
   "hosts": {
     "title": "Host Manager",
diff --git a/src/locales/zh/translation.json b/src/locales/zh/translation.json
index b2860f90..16d7ee7d 100644
--- a/src/locales/zh/translation.json
+++ b/src/locales/zh/translation.json
@@ -474,7 +474,11 @@
     "createBackup": "创建备份",
     "exportImport": "导出/导入",
     "export": "导出",
-    "import": "导入"
+    "import": "导入",
+    "passwordRequired": "密码为必填项",
+    "confirmExport": "确认导出",
+    "exportDescription": "将SSH主机和凭据导出为SQLite文件",
+    "importDescription": "导入SQLite文件并进行增量合并（跳过重复项）"
   },
   "hosts": {
     "title": "主机管理",