Unless you are expert in device driver development I would not recommend anyone to attempt doing a file system filter driver themself if they are on a tight deadline. I would recommend you pick up framework and build on that , it easier and more reliable. I had one such requirement from a client which required on the fly data modification ( encryption and Access control ) and after some search found the following –

• Very hard to write,avoid unless you know what you are doing.


• Hard to debug and develop


• Very few experts and project development costs are very expensive if outsourced


• No real reference source code unless you wish to invest a lot of time


• OSR is where the experts hang out and best resource and forum if you plan to do it yourself.

Doing some research we planned to use a commercial framework for faster turn around and more reliability, since I am not a Device driver experts and here are some which i found which offer File system filter driver with sources.

• Crypto Driver – Its a new entrant , plug and play architecture which is easily extendable. Not much documentation or support options for now.


• Alfa Transparent File Encryptor – Well documented and complete in most ways. You cannot change crypto unless you get the code.


• CallBackFilter – Very flexible,well documented and was found easiest to use, They have very flexible pricing which is startup friendly.


• OSR DMK – Best in the league but was way out of our budget.

If you find more do let me know i will add them to my list and keep them for reference.