@M_a_v If you can generate the pdf files to include the subscribers email address in the file name then you could create a link to the personalised file
http://mysite.com/some_file_name_jsmith@xxx.com.pdf
but I don’t know how well including @ and . characters like that will work.
It is also not secure as, if I know someone else’s email address, I could access their file, but that might not be an issue for you.
A more secure way is to use the subscribers unique id, the 32 character value, which cannot easily be guessed. But then the system generating the pdf files would need to know those unique id values.
How are you intending to map subscribers to their individual file?