or shift format to password protected pdf or zip - but it would be tedious to invent & then not forget 800+ passwords
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if you plan to circulate data , surely burn-to-cd is safer than flashdrive - no-one can add a virus or alter content on a finalized CD - if you have a lack of trust issue then do you really want to re-mount that flash drive once it's returned ?
PS many flash drives come with their own pre-installed security software, so you can protect the whole drive to various levels , depending on how smart that software is