Lists, Views an webpart

Hello all,
I'm new on this. I attended the "Sharepoint Site Collection and Site Administration" Course and i'm building 2 sharepoint portals.
I need to share contents located in one big list. I've been reading some papers and found that it is possible to create a list, in the top site, build a webpart from that list and then place it on diferent pages, choosing diferent views.
My sitecollection has two main sites, and one main site has several subsites. I need to give diferent types of access to users in those sites and subsites.
Is it possible to give access to a user in a subsite (that has that webpart with a specific view) stoping him to access data in the entire list, accessing only the data shown in that specific view?

Thank you very much