How to edit .asec or compare two .asec files witch are stored by app at location mnt/.android_souce/app name.asec. This file get updated whenever data connection is on / while using app to upload and download app data . This folder not able to access on non rooted Phone but can able to access on pc with usb . What are capable software that can read and writing easily .asec file ?
The ASEC file is a TwoFish encrypted container which in turn is a dm-crypt volume that gets mounted by Linux's device mapper at /mnt/asec/[app_id] (The AppID is based on the package name). The 128-bit key to the container can be found in /data/misc/systemkeys but this file requires root access for reading. You can read exactly how the encryption works here. Moving on, the mounted volume will contain an unencrypted apk of the application. In order to change the desired data, it's necessary to understand where the data is stored and how it is done. For that, the application will have to be reverse-engineered by either decompilation - list of tools - or by disassembly to smali and posterior debugging using tools such as apktool and androguard.
Sometimes, these steps can be bypassed as the app uses a database file in it's directory (usually /data/data//) that you can edit with any SQLite editor, such as SQLite Debugger or using the sqlite3 set included by default in Android, or keeps the relevant information in memory in a way that is trivial to change it with a memory editor such as GameGuardian. However, the data can be stored server-side and transmitted through the network when app is started and then kept in memory in a not easily modifiable way so that in order to be able to change it, you will need to not only reverse-engineer the application but also to intercept and modify the traffic it receives in order to transmit the new information to the application.