Android SharedMemory 本身并不提供加密和解密功能。但是，你可以在將數據寫入 SharedMemory 之前進行加密，并在從 SharedMemory 讀取數據后進行解密。這可以通過使用對稱加密算法（如 AES）來實現。

以下是一個簡單的示例，展示了如何使用 AES 加密和解密數據：

1. 首先，確保你已經在項目中添加了 AES 庫。在 build.gradle 文件中添加以下依賴：

implementation 'com.google.crypto:crypto-js:4.1.1'

2. 創建一個加密和解密函數：

import com.google.crypto.Cipher;
import com.google.crypto.spec.IvParameterSpec;
import com.google.crypto.spec.SecretKeySpec;
import org.json.JSONObject;

import java.nio.charset.StandardCharsets;
import java.util.Base64;

public class AESUtil {
    private static final String AES_ALGORITHM = "AES/CBC/PKCS5Padding";
    private static final String AES_KEY = "your-secret-key"; // 請替換為你的密鑰
    private static final String AES_IV = "your-initial-vector"; // 請替換為你的初始向量

    public static String encrypt(String data) throws Exception {
        SecretKeySpec secretKeySpec = new SecretKeySpec(AES_KEY.getBytes(StandardCharsets.UTF_8), AES_ALGORITHM);
        IvParameterSpec ivParameterSpec = new IvParameterSpec(AES_IV.getBytes(StandardCharsets.UTF_8));
        Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec);
        byte[] encryptedBytes = cipher.doFinal(data.getBytes(StandardCharsets.UTF_8));
        return Base64.getEncoder().encodeToString(encryptedBytes);
    }

    public static String decrypt(String encryptedData) throws Exception {
        SecretKeySpec secretKeySpec = new SecretKeySpec(AES_KEY.getBytes(StandardCharsets.UTF_8), AES_ALGORITHM);
        IvParameterSpec ivParameterSpec = new IvParameterSpec(AES_IV.getBytes(StandardCharsets.UTF_8));
        Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(encryptedData));
        return new String(decryptedBytes, StandardCharsets.UTF_8);
    }
}

3. 使用加密和解密函數處理 SharedMemory 中的數據：

import android.os.Build;
import android.os.Environment;
import android.os.storage.FileChannel;
import android.os.storage.StorageManager;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileLock;
import java.nio.channels.OverlappingFileLockException;

public class SharedMemoryManager {
    private static final String SHARED_MEMORY_FILE_PATH = Environment.getExternalStorageDirectory().getAbsolutePath() + "/shared_memory.dat";

    public static void writeEncryptedDataToSharedMemory(String data) throws Exception {
        String encryptedData = AESUtil.encrypt(data);
        File sharedMemoryFile = new File(SHARED_MEMORY_FILE_PATH);
        if (!sharedMemoryFile.exists()) {
            sharedMemoryFile.createNewFile();
        }
        try (FileOutputStream fos = new FileOutputStream(sharedMemoryFile);
             FileChannel fileChannel = fos.getChannel()) {
            FileLock lock = null;
            try {
                lock = fileChannel.tryLock();
                if (lock != null) {
                    try {
                        fos.write(encryptedData.getBytes(StandardCharsets.UTF_8));
                    } finally {
                        lock.release();
                    }
                }
            } finally {
                if (lock != null) {
                    lock.release();
                }
            }
        }
    }

    public static String readEncryptedDataFromSharedMemory() throws Exception {
        File sharedMemoryFile = new File(SHARED_MEMORY_FILE_PATH);
        if (!sharedMemoryFile.exists()) {
            return null;
        }
        StringBuilder encryptedData = new StringBuilder();
        try (FileInputStream fis = new FileInputStream(sharedMemoryFile);
             FileChannel fileChannel = fis.getChannel()) {
            FileLock lock = null;
            try {
                lock = fileChannel.tryLock();
                if (lock != null) {
                    try {
                        int bytesRead;
                        byte[] buffer = new byte[1024];
                        while ((bytesRead = fis.read(buffer)) != -1) {
                            encryptedData.append(new String(buffer, 0, bytesRead, StandardCharsets.UTF_8));
                        }
                    } finally {
                        lock.release();
                    }
                }
            } finally {
                if (lock != null) {
                    lock.release();
                }
            }
        }
        return encryptedData.toString();
    }

    public static String decryptSharedMemoryData() throws Exception {
        String encryptedData = readEncryptedDataFromSharedMemory();
        return AESUtil.decrypt(encryptedData);
    }
}

請注意，這個示例僅用于演示目的。在實際應用中，你需要考慮更多的安全因素，例如密鑰管理和存儲、初始向量的安全性等。此外，由于 SharedMemory 在 Android 上的支持有限，你可能需要使用其他方法（如使用文件或數據庫）來存儲加密數據。