

Thanks for cross-posting and tagging me!
InfoSec Person | Alt-Account#2


Thanks for cross-posting and tagging me!


Someone asked the same question on a cross-post: https://lemmy.world/comment/14943883
Tl;Dr is the recent rust drama.
More info: https://www.phoronix.com/news/Asahi-Linux-Lead-No-Upstream


My bachelor’s thesis was about comment amplifying/deamplifying on reddit using Graph Neural Networks (PyTorch-Geometric).
Essentially: there used to be commenters who would constantly agree / disagree with a particular sentiment, and these would be used to amplify / deamplify opinions, respectively. Using a set of metrics [1], I fed it into a Graph Neural Network (GNN) and it produced reasonably well results back in the day. Since Pytorch-Geomteric has been out, there’s been numerous advancements to GNN research as a whole, and I suspect it would be significantly more developed now.
Since upvotes are known to the instance administrator (for brevity, not getting into the fediverse aspect of this), and since their email addresses are known too, I believe that these two pieces of information can be accounted for in order to detect patterns. This would lead to much better results.
In the beginning, such a solution needs to look for patterns first and these patterns need to be flagged as true (bots) or false (users) by the instance administrator - maybe 200 manual flaggings. Afterwards, the GNN could possibly decide to act based on confidence of previous pattern matching.
This may be an interesting bachelor’s / master’s thesis (or a side project in general) for anyone looking for one. Of course, there’s a lot of nuances I’ve missed. Plus, I haven’t kept up with GNNs in a very long time, so that should be accounted for too.
Edit: perhaps IP addresses could be used too? That’s one way reddit would detect vote manipulation.
[1] account age, comment time, comment time difference with parent comment, sentiment agreement/disgareement with parent commenters, number of child comments after an hour, post karma, comment karma, number of comments, number of subreddits participated in, number of posts, and more I can’t remember.


Are you talking about this: I have toyota corola?
Thanks for the question!
As long as caches have existed, very similar styles of side channels have been demonstrated since the late 90s. A lot of the terminology we use (flush+reload, flush+flush…) are attack techniques that have been already demonstrated on CPU caches, and these demonstrations are at least a decade old.
Flush+Reload: https://www.usenix.org/conference/usenixsecurity14/technical-sessions/presentation/yarom
Flush+Flush: https://gruss.cc/files/flushflush.pdf
Invalidate+Compare (GPU caches, 2024): https://www.usenix.org/conference/usenixsecurity24/presentation/zhang-zhenkai
My colleague, Hannes, found similar styles of attacks existed with the Linux DNS cache too: https://hannesweissteiner.com/pdfs/dmt.pdf (also published at NDSS 26!)
The one really big difference between the page-cache side channel and other side channels is the “monitor” primitive. There are methods that the OS provides which directly report the presence of a page in cache. These are syscalls like
mincore(mitigated in 2019),preadv2 + rwf_nowait(unmitigated), andcachestat(mitigated in 2025).With these syscalls, we don’t even have to rely on timing information (is page access fast -> cached; is it slow -> not cached). These syscalls really set the page-cache side channel apart because you can nondestructively figure out whether a page is in cache.
The page-cache side channel was first explored in 2019. It was explored on Linux but also on Windows by my advisor et al.: https://gruss.cc/files/pagecacheattacks.pdf
Hope this answers your question :D