Q:

How to restrict user to take data back up of our application data through itunes sync process?  through coding

how do i restrict taking an application data backup using itunes sync..
its a requirement from my client that ....from application should not allow taking a backup of any files. 
Can you please suggest me whether this is possible or not....
if yes can you please suggest me ways to do it..

A:

For data security and if you're running on iOS 4.0 or greater, look at NSData's writeToFile:options:error: 
Docs for option NSDataWritingFileProtectionComplete state:
A hint to set the content protection attribute of the file when writing it out.  In this case, the file is stored in an encrypted format and may be read from or written to only while the device is unlocked.  At all other times, attempts to read and write the file result in failure. 
This option set on a file stored in the cache directory should do what you need. 