We have a new analysis of SDR by Leo Reyzin.

Disclaimer:

• This is all in review (we had it in early June only)
• Given what we saw, we are confident enough to communicate this though. It looks promising

TL;DR of this new analysis:

• The security margin of SDR, as deployed now, is actually much higher than we thought (both in cost and latency model). It is likely to be around 10x higher.
• Adding (few) layers may be a strategy to improve security substantially
• E.g., we are checking we can obtain (say) 50% higher security margin by adding only 2 layers. This is in review but in sight as a potential result.

Sample from the pdf analysis (still not public) below: