[vtkusers] adding encryption capability to VTK reader/writers

[Hamid]

Hi

I'd like to add encryption/decryption capablity to vtk. I have couple of  
files, which I have encrypted, and want to read them in and use vtk on  
them. My encryption/decryption algorithm is a simple class which can read  
data byte by byte untill it feels its 4096-byte long buffer and then it  
decrypts them. (I can change the buffer length)

Since my files are huge and decryption process takes a lot of time, I was  
thinking of taking advantage of stream property of vtk and integrate my  
code into reader/writers of it. So whenever user requests new data from my  
file, it gets decrypted on the fly.

So can you please help me ? I know this is not a simple issue but any type  
of help is appreciated.
I have checked the vtk classes and to me it seems that I have to work with  
Update() members of vtkImageData and vtkDataObject.

Can you please name a reference (web link, book, article...) that will  
help me in this task ?

Thanks in advance
Hamid