What did Arkham Intelligence claim about Zcash tracking?

Arkham Intelligence said it labeled more than 53% of all Zcash transactions and linked about $420 billion in ZEC transaction volume to identifiable people and institutions.

Did Arkham break Zcash’s cryptography?

No. Arkham said it did not crack Zcash’s privacy technology or shielded cryptography. Instead, the firm relied on exchange records, wallet clustering, seizure data and analysis of transparent wallet activity.

Why can Arkham track so much Zcash activity?

Zcash uses an opt-in privacy model. Users can choose between transparent T-addresses, which are publicly visible, and shielded Z-addresses, which hide transaction details using zero-knowledge proofs.

What did Zcash founder Zooko Wilcox say about Arkham’s findings?

Zooko Wilcox said Arkham did not deanonymise funds stored inside Zcash’s shielded pool. He argued fully shielded transactions remain cryptographically private and impossible to trace with current information.

What is the difference between T-addresses and Z-addresses in Zcash?

T-addresses function similarly to transparent Bitcoin wallets where balances and transfers are publicly visible. Z-addresses use advanced privacy technology to hide the sender, recipient and transaction amount.

Why is Zcash’s privacy considered “opt-in”?

Unlike some privacy coins where all transactions are hidden by default, Zcash allows users to choose whether transactions are transparent or shielded. That flexibility improves compatibility but reduces universal privacy coverage.

How much ZEC is currently held inside shielded pools?

The report said less than a quarter of all circulating ZEC was stored in shielded pools as of late 2025. Most activity still reportedly flows through transparent addresses, especially on centralised exchanges.

Why are exchanges important to Arkham’s tracking ability?

Most major crypto exchanges use transparent Zcash addresses for operational and compliance reasons. That creates visible transaction trails which analytics firms can cluster and associate with real-world entities.

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Arkham says it tracks most Zcash activity

Written by Heidi Cuthbert Published May 26, 2026, 2:03 AM

Arkham Intelligence said it successfully labeled more than 53% of all Zcash transactions, linking roughly $420 billion in transaction volume to identifiable individuals and institutions.

The firm said its tracking covered about 48% of all transaction inputs and outputs and roughly 37% of total ZEC balances, equivalent to around $2.5 billion.

Arkham clarified that it did not break Zcash cryptography and instead relied on exchange data, entity clustering, government seizure records and analysis of transparent wallet activity.

The disclosure reignited debate around Zcash’s opt-in privacy design, which allows users to choose between transparent T-addresses and shielded Z-addresses secured by zero-knowledge proofs.

Zooko Wilcox responded that fully shielded transactions remain cryptographically private and said Arkham could not deanonymise funds stored inside the shielded pool.

“Arkham didn’t actually deanonymise any ZEC that was held at rest in the shielded pool,”

Wilcox said, adding that such tracking would be impossible because the required information is not publicly available.

The controversy resurfaced as Zcash rallied on growing interest in privacy-focused crypto infrastructure and the approaching NU7 network upgrade, which is expected to strengthen privacy protections within the network’s newer Orchard shielded pool.

At the time of reporting, Zcash price was $632.61.