I'm not an expert on Tor code, so I can only speculate and agree partly with you: it matters where it is used. But temporary keys do not necessarily help agains

I'm not an expert on Tor code, so I can only speculate and agree partly with you: it matters where it is used. But temporary keys do not necessarily help against an attacker who has access to all/most past Tor traffic. RSA-1024 is used in node identification and hidden services, the weaknesses are known: https://blog.torproject.org/blog/prism-vs-tor https://blog.torproject.org/blog/prism-vs-tor https://blog.torproject.org/blog/hidden-services-need-some-love https://blog.torproject.org/blog/hidden-services-need-some-l... (note: current state of affairs unknown to me since Tor doesn't seem to update these documents)