> Where is the public pgp key for the .asc file ?
Same place as the isos:
https://cdimage.trisquel.info/trisquel-images/trisquel-archive-signkey.gpg
The link is displayed in the download results page.
> Why not sign the hash files instead of the .iso ? or both ?
Both are, e.g.
https://cdimage.trisquel.info/trisquel-images/sha256sum.txt.asc
> Why put a separate file for each hash ?
Because that way the download results page (the one you see after you click
on download) can link to the specific hash of what you downloaded, instead of
a more confusing list.
