Research note 02
Round exits blend in
An exact withdrawal amount is a fingerprint. Restricting exits to round values makes them common.
Exact exit (fingerprint)
12,347.81
Grid exit (shared)
10,000
Stays shrouded
2,347.81
An exit of 12,347.81 is close to unique on the chain. An exit of 10,000 looks like every other exit of 10,000.
The leak
If someone shrouds 12,347.81 and an exit of 12,347.81 appears later, no cryptography is needed to connect them. Even partial withdrawals leak when the remaining balance is later withdrawn in full.
The fix being considered
The circuit could accept only exit amounts of the form m × 10^k, a single significant digit. An exit of 10,000 is shared with every other exit of 10,000, and whatever is left over stays in a note.
It costs flexibility: paying an exact invoice publicly would take two exits or a private transfer first. For holders who exit rarely, that is a small price.
Status
This is research, not a shipped feature. Whether and how it lands in the pool will be written up in the roadmap and the parameters page.
Next note
Exits that leave together