> There is a reason why the authors limited their considerations to transactions before the RingCT update.
No, they did not. The 80% figure comes from weaknesses of clients post RingCT update.
No, they did not. The 80% figure comes from weaknesses of clients post RingCT update.
Applicability to current and future transactions using RingCT. The weakness studied in this section is pri- marily a concern for transactions made in the past, as transactions using the new RingCT transaction option are generally immune.
The estimate of the bias given in the paper for the current default and typical usage is that the most recent potential source has a probability of 45% instead of the ideal 20%. In fact this likely applies to 100% of current transactions, not 80%.
This is a known issue, and not ideal, and the quantitative results in the paper are helpful, but the paper does not show what you claim it shows.
RingCT is immune to the methods in Section 3 as stated in the last paragraph of Section 3.
Section 4 does not trace any transactions. It identifies a probability bias which make the ring sigs less efficient, but still functional.