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Hubzilla DevelopmentMAYBE just had an idea... of course, it's probably been thought of... but in case it hasn't........
I have to summarize this quick because I'm walking out the door --- if it's incomprehensible, sorry - I'll try to explain it more later.
posting_host polls forum_host to see if requesting_channel is in the forum before allowing access to the file. Could be tokenized in a 3-way handshake (requesting_channel_host gets token from forum_host to that requesting_channel_browser presents to posting_host which is validated with forum_host).
Delegation could be represented in the DB on the posting_host in attach.allow_cid as instead of
Like I said... QUICK summary - feel free to shoot it down - or ask questions.