More secure protection of files

Word documents past Office 97 or so are certainly not insecure - there is a big fuss over Rainbow Tables as though they were a magic bullet, but all they really are is a precalculated brute force table; by looking up the output of the brute force in a table (instead of trying each key in turn) you can rapidly get the key *provided it is in the table* - therefore, the key to secure word documents is to pick a key that isn't in the available rainbow tables (which in practice means 10 characters or more, and not made up of dictionary words) - PDF and many other encryption types are also subject to the same limitation.

For mail filters, password protected zipfiles are often blocked on sight - too many viruses have used this as a vector in the past. To a certain extent, office documents (which could contain macros) and pdf documents (which could contain scripts) are subject to scrutiny and may be blocked if they are encrypted, but less often than zipfiles are.

From a novice point of view, what changed post office 97 , and what algorithm is used for both word and PDF? Does their exist anywhere a site or list that lists all common encryption tools and features within software and what hashing algorithm they use. I searched a while back but nothing really showed up.

In a nutshell are we saying the passwords for docx and PDF if the user picks a strong password are good enough, and no 3rd party tool is required to add more protection to them? I was just going on hearsay that winzip has a stronger algorithm than office for passwords but maybe that is a myth....

Cheers