First of all, I am new here and must quote this is really very excellent software. Currently using trail version.
Now my issue is: The application on which I am working needs secure database AND portable as well like SQLite (but it is not secured according to my information). So please let me know other supported databases which are secure and portable as well or the method by which I can secure SQLite db.
Thanks in Advance
If your SQLite database file needs to be updated by your compiled application, you should use encryption for it.
If you only do read operations, you can compile it into the EXE file and make it virtual, so that it will remain in memory and accessible from PHP, but it cannot be easily copied since it is not on the hard disk.
I am implementing 1st option, means my database is not compiled in application and being updating time to time. Will you please guide any method for encryption???
I am not very familiar with databases 
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Is there any substitute for SQLite having password protecting feature???
You could encrypt sensitive data before storing it into the SQLite database.
Or you might find some useful information over here: http://www.sqlite.org/search?q=encryption
can is see screenshot sir on how to dot it? i