make Folder in sdcard with password protected: android

Question

i am saving video and image in a folder ..now i want to make this folder as password protected , means while opening this folder needs to enter a password for view the file inside it
hope here ill get any relevant answer for doing this...if there some any other possible please suggest..

                     try {
                        dirName = "/mydirectory/";
                        fileName = new Long(
                                SystemClock.currentThreadTimeMillis())
                                .toString()
                                + ".png";
                    } catch (NullPointerException e) {
                        // TODO: handle exception
                    }
                    try {
                        if (android.os.Environment
                                .getExternalStorageState()
                                .equals(android.os.Environment.MEDIA_MOUNTED)) {
                            File sdCard = Environment
                                    .getExternalStorageDirectory();
                            File dir = new File(sdCard.getAbsolutePath()
                                    + dirName);
                            dir.mkdirs();

                            File file = new File(storedImagePath);

                            os = new FileOutputStream(file, true);

                            byte[] byteArray = receivedImageData.getBytes();

                            byteArray = Base64.decode(byteArray, 0);

                            os.write(byteArray);
                            os.flush();
                            os.close();

                        } else {

                        }

                    } catch (Exception e) {

                    }

Answer 1

I'd like to suggest a different/feasible approach, Encrypt your file!

Look at this answer!

Even if you are successful in implementing a password protection (Wow!) here are the cons,

1. This will only protect when your app is running.
2. SD cards are supposed to be transferred(Hence your app cannot protect the files on SDcard always).