Leakscope

MAINNET 3,428,143–3,515,250

Observatory · Zcash mainnet · blocks 3,428,143–3,515,250 · 28 Jul 2026 → 11 Oct 2026

24.6% of withdrawals since Ironwood launched can be traced.

Shielded Zcash hides sender, receiver and amount. But value entering or leaving a pool, or moving from Orchard to Ironwood, crosses a public boundary with its exact amount.

Of 82,581 transactions that withdrew to transparent addresses, 5,128 match exactly one earlier deposit plus their own fee, and 15,215 more were spent straight back into a pool. No cryptography was broken, and we measured how often these links are wrong. Leakscope plays that observer, so you can see what it sees before you transact.

Check a transactionPlan a migration
Withdrawals82,581

transactions moved shielded value to a transparent address.

Round trips15,668

times deshielded coins were spent straight back into a pool: linked with certainty.

Orchard → Ironwood24,725

migrations revealed 3,268,327 ZEC in exact amounts; 74% used a ZIP-318 standard amount.

Fingerprinted migrations3,763

moved an amount nobody else moved within 30 days: a tag later withdrawals can be matched to.

Fig. 01 — Every public boundary event, block 3,428,143 → 3,515,250
loading boundary events…
Shielding events are plotted above the pools, deshielding events below, moves between pools inside them. A thread joins two transactions an observer can link from public data alone.

Each dot is one public boundary event: shieldings above the pools, deshieldings below, height = amount on a log scale. Each thread is a pair an observer can link. Matching by amount is probabilistic; see the method for what each thread means and how we checked it.

02 · Day by day

The pools are busy. The edges are not.

Most activity stays shielded, but every withdrawal is a chance to leak. Accent marks withdrawals whose amount matches exactly one earlier deposit. On the right, Orchard is being emptied into Ironwood: the migration that ZIP 318 is meant to make safe.

Fig. 02 — Withdrawals per dayamount matches exactly one deposit

Hover a day.

01k2k3k4k28 JUL07 AUG17 AUG27 AUG06 SEP16 SEP26 SEP06 OCT
Fig. 03 — Shielded actions per day IW ORC SAP

Orchard drains, Ironwood fills. Hover a day.

020k40k60k28 JUL07 AUG17 AUG27 AUG06 SEP16 SEP26 SEP06 OCT
Daily series
DayDeshielding txsLinked to one depositShielding eventsPool crossingsIronwood actionsOrchard actionsSapling actions
28 Jul 2026411555231605515827329522
29 Jul 202641344566840348813219813
30 Jul 20264055157068333858803876
31 Jul 20264575350349331858622621
01 Aug 20263715240139423317235621
02 Aug 20265045149245832047014614
03 Aug 20265395450845528829035707
04 Aug 20265485053955835526408630
05 Aug 20264894651936831045897610
06 Aug 20264815149539830836179721
07 Aug 20264634948447930448561568
08 Aug 20264565145073231618996585
09 Aug 20265244950058831966060594
10 Aug 20265294650282434478689570
11 Aug 20264304750184834175979587
12 Aug 20264685048269831735403608
13 Aug 20265035248956230434997616
14 Aug 20263784451648029944240549
15 Aug 20263714342242022833265572
16 Aug 20264494447447631584065734
17 Aug 20264834851752735763524605
18 Aug 20265125050438434962954665
19 Aug 20265885462961547904992604
20 Aug 20267345467153346185168661
21 Aug 202611396585794163648500656
22 Aug 20267476068379546776192620
23 Aug 20267435573770971304833667
24 Aug 202682562746557502735601010
25 Aug 20266205257544536392567622
26 Aug 20266285564022633961878654
27 Aug 20265966061825135181554669
28 Aug 20266955257517034131007600
29 Aug 20267365367917837711539643
30 Aug 202675058679289397115851279
31 Aug 20268335166224442321487622
01 Sept 2026878576741844131963610
02 Sept 20261981763909222326931451679
03 Sept 202636101274074437461692831546
04 Sept 20261621751286328156342097533
05 Sept 20261682571430379153812852615
06 Sept 202632351582403402180782402676
07 Sept 20261397711291240175471342594
08 Sept 202611816699919989711336689
09 Sept 202614947989425875731394580
10 Sept 20269875984126858241305695
11 Sept 2026808646221274035561854
12 Sept 202682657708714330454547
13 Sept 202678056781874402457526
14 Sept 2026105382245510615926504770
15 Sept 202612677515991019262597823
16 Sept 20261732784554191291561670562
17 Sept 202632621072364260228701394670
18 Sept 20262792101362738395320312678029
19 Sept 2026189675283738330659841875
20 Sept 2026246613066658604832910642202
21 Sept 202627921741907517303045102107
22 Sept 202639421991877883277178192630
23 Sept 20261911931199432137117141983
24 Sept 20261594779971438908533728
25 Sept 202610966989236587626831235
26 Sept 20261236539761638811670850
27 Sept 202613066910311098674475820
28 Sept 2026138376119422883503921106
29 Sept 202612227210141087248485734
30 Sept 2026113577911816106388797
01 Oct 202697765859735750441611
02 Oct 2026103266770525192293514
03 Oct 202677071670804241301713
04 Oct 20261016677275816867435515
05 Oct 202689061706755092437580
06 Oct 202694961702885704288579
07 Oct 2026117574930507799299662
08 Oct 2026107267810357680242580
09 Oct 2026988641023616279245550
10 Oct 202683671787505803252646
11 Oct 202649341428263247152387
03 · Leak classes

Six ways the chain talks.

Each detector models one concrete observer with nothing but the public chain. Every example below is a real mainnet finding from this range.

01

Round trip 15,668 found

Coins leave a shielded pool for a transparent address, and that very output is spent back into a pool. The transparent hop is a public chain of custody: both ends are linked with certainty.

Real example · Round trip
criticalRound tripblock 3,456,672

Re-shielded coins that had just been deshielded (67532.0325 ZEC)

This shielding spends a transparent output created by an earlier deshielding. Anyone can follow the coins out of the shielded pool and back in, so both ends are linked.

Anonymity set
1 — fully linked
Amount
67532.0325 ZEC
Transactions
bb6f212a7e…cc7fcheckexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)8f5d830993…1ae0checkexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)
02

Quick round trip 4,833 found

A deposit, then within 100 blocks (about two hours) a withdrawal of the same amount minus a standard fee, and no other deposit fits. The pool held the money briefly and hid nothing.

Real example · Quick round trip
highQuick round tripblock 3,452,468

Withdrawal of 993.99954824 ZEC matches exactly one earlier deposit (6 blocks before)

Only one value entered the sapling pool in the previous 30 days that equals this withdrawal plus its own fee. Measured on mainnet, links of this kind (non-round amount, within 100 blocks) are right about 99% of the time — no cryptography is broken, only amounts are matched.

Anonymity set
1 — fully linked
Amount
993.99954824 ZEC
Transactions
ffd72c30c8…2a64checkexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)f22679d4c7…afb8checkexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)
03

Amount match 406 found

A withdrawal that equals exactly one deposit in the previous 30 days, after allowing for any standard fee. Unusual amounts are fingerprints: the rarer the amount, the stronger the link.

Real example · Amount match
mediumAmount matchblock 3,449,978

Withdrawal of 477.25288468 ZEC matches exactly one earlier deposit (477 blocks before)

Only one value entered the sapling pool in the previous 30 days that equals this withdrawal plus its own fee. Measured on mainnet, links of this kind (non-round amount, within a day) are right about 85% of the time — no cryptography is broken, only amounts are matched.

Anonymity set
1 — fully linked
Amount
477.25288468 ZEC
Transactions
baa8ed2527…149bcheckexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)26c86ec435…4acacheckexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)
04

Address reuse 16,510 found

A transparent address that once received a withdrawal later shields funds again. One address, two shielded activities, one owner.

Real example · Address reuse
highAddress reuseblock 3,487,016

Shielded from an address that earlier received deshielded funds

Address t1KfwsnwJeNRVjQGBDZhwKskpQbih2qx5Ua received a withdrawal from the shielded pool and later shielded again. Reusing a transparent address ties both shielded activities to one owner.

Anonymity set
1 — fully linked
Amount
1096.56208875 ZEC
Transactions
d93d4961a2…1780checkexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)a9d5a7c8e7…933ccheckexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)
05

Pool crossing 31,842 found

Moving value from Orchard to Ironwood passes a public turnstile that shows the exact amount. Orchard is frozen, so every holder must cross. A one-of-a-kind amount is a fingerprint later withdrawals can be matched against; ZIP 318 standard amounts blend in.

Real example · Pool crossing
mediumPool crossingblock 3,450,022

Exact amount revealed moving orchard → ironwood: 52122.00528299 ZEC

Moving value between shielded pools passes through a public turnstile, so the exact amount is visible. No other move of this amount happened nearby: it acts as a fingerprint that later amounts can be matched against.

Anonymity set
1 — no other move of this amount nearby
Amount
52122.00528299 ZEC
Transactions
6110fac9b8…83d6checkexplorer ↗ (Opens zecblock.com in a new tab. That explorer learns you looked up this transaction.)
06

Fee fingerprint 5,011 found

Almost every wallet pays exactly the ZIP-317 fee. A transaction that pays something else stands out and narrows down which software, and so which user, made it.

Real example · Fee fingerprint
04 · Use it

See it before they do.

Three tools, all running in your browser. Nothing you type is sent anywhere.

→

Check a transaction

Paste a txid and see every leak it is part of, with the transaction it links to.

→

Pre-flight a transfer

Before you shield, deshield or migrate: a score, the crowd you would hide in, and a ZIP-318 split with a schedule.

→

Scan your wallet

Use a viewing key, locally, to find your own transactions and get a personal leak report.

→

Read the method

The observer model, every detector, its assumptions and false-positive caveats, and how we validated it.