Word document Secuirty

[Dmc]

Currently i am producing a lot of documents for the
company that i work for. The problem is that some people
are will to take my work and change details and say that
the work is there own (people my own level and who are
basically seeking points with the management). The
documents use the Forms feature of micrsoft word and
students would enter there details into these documents.
These documents will not change as they are for actuall
exisitng examinations.

What i would like to know is the best way to protect my
docuemtns, currently i have a choice of:

a) Adobe Acrobat - the problem with this is that i need
people to be able to enter details into these documents
through Forms details;

b) Microsoft Word - Tools menu Protect Document submenu,
if i entered a password for this, does it matter about the
length of the passowrd, i know there are programs to crack
the password and i have heard the longer the password the
harder it is to crack.

c) Microsoft Word - Password, a good idea but i do not
want users to have to select this option.

What are peoples views, how would they do it. Bearing in
mind i DO NOT want people to be able to change them and if
they are able to i want to make it as differcult as i can!