but why not directly encrypt the data.

from the book \"The Windows NT Device Driver Book:A Guide for
               Programmers\"
a sentence is that:
   a filter drive can add function,such as compress and
   encrypt,to a equipment,other then modify the lower device
   drive.

now I have the Microsoft a sample to r/w a easydisk(usb).

the first way is Modifying this sample,which is my best wish
to Directly encrypt the transfer data.

the second way is write a new filter drive,which I do not wish,because I am a new hand for writing device driver.

maybe the third way is doing as you said,add some valudate
function in this sample,but I think maybe it\'s more difficult.

All the Problems is I have not time to leave.
Do you have some example for me?
If Have,Could you give it to me.
thank you very much!
  

> but why not directly encrypt the data.
Becauz the performance and develop time if u care!!!

> filter drive can add function,such as compress and
> encrypt,to a equipment,other then modify the lower device
> drive.
I can\'t give u more info,becauz it\'s complex to me about the encrypt.

> the first way is Modifying this sample,which is my best
> wish to Directly encrypt the transfer data.
I ever study the sample, but it\'s VxD,not WDM.
I give it up.Just Re-writing the dirver now.!!!

> the second way is write a new filter drive,which I do not > wish,because I am a new hand for writing device driver.
No!! Then I think just modify the r/w function of the sample.

[编辑 -  4/23/02 作者： Nouk]

I am very happy you had read this sample.

yes,it\'s not a pure wdm drive,the another depart is vxd.

but i am not familiar with vxd.I even do not know the vxd.

but I think one depart is wdm,I can only modify this part,

the function Umss_Buffertransfer i think is tranfering the

data,but I can not get the right data.espcailly the IN DATA

and the OUT DATA is not right.

why?