Shielded Transactions & Privacy

All ZEC in existence lives in one of four "value pools." Each pool represents a different generation of Zcash technology, with increasing privacy and efficiency. Think of them as separate vaults within the same bank — you can move funds between them, but each has different properties.

Transparent pool works identically to Bitcoin — balances and transaction details are visible to everyone. This pool exists for compatibility and for cases where transparency is desired (e.g., exchange deposits, auditable donations).

Sprout pool was the original shielded pool from Zcash's 2016 launch. It proved that private transactions on a blockchain were possible, but the proofs were slow to create (over a minute on some hardware) and required a trusted setup ceremony. Sprout is effectively deprecated — modern wallets no longer support sending to Sprout addresses, and very little ZEC remains in this pool.

Sapling pool (2018) was a breakthrough in usability. Proof generation dropped from minutes to seconds and memory requirements dropped dramatically, making shielded transactions practical on phones and lightweight hardware for the first time.

Orchard pool (2022) represents the current state of the art. It uses the Halo 2 proving system, which eliminates the need for a trusted setup entirely — removing a long-standing concern about the security assumptions of shielded transactions. Orchard is accessed through unified addresses (u1).

The Dashboard's "Value Pool Distribution" chart tracks how ZEC is distributed across these pools over time. A growing share in Sapling and Orchard indicates increasing privacy adoption across the network.

Moving ZEC between transparent and shielded pools has specific terminology:

• Shielding: Sending ZEC from a transparent address to a shielded address. The funds become private — after this point, the transaction trail goes dark. On this explorer, shielding transactions appear as "Mixed" type since they have both transparent inputs and shielded outputs.
• Deshielding: The reverse — sending ZEC from a shielded address to a transparent address. The funds become publicly visible again. This is sometimes necessary for exchange deposits or regulatory compliance.

The privacy benefit of Zcash is strongest when ZEC stays within shielded pools. Each shielding transaction effectively "breaks the chain" of public transaction history. Funds that have been shielded and then deshielded to a new address are not directly linkable to the original transparent source.

Now that you understand how ZEC moves between transparent and shielded pools, a natural question arises: what if you need to share your shielded transaction history with someone — an auditor, a tax preparer, or a business partner?

Shielded transactions are private by default, but Zcash doesn't force an all-or-nothing approach. Every shielded address has an associated viewing key that its owner can share to grant read-only access to transaction details — without giving up the ability to spend funds.

This enables important use cases:

• Audits & compliance: A business can share a viewing key with an auditor to prove income or spending, without making that information public on the blockchain.
• Tax reporting: Users can generate transaction history for specific addresses without exposing their full financial picture.
• Delegation: A fund manager can grant read-only visibility to investors without sharing spending authority.

Viewing keys are a key differentiator from "always-on" privacy systems. They make Zcash compatible with regulatory requirements while keeping the default private — users opt in to transparency on a case-by-case basis rather than having to opt in to privacy.

Every Zcash address starts with a prefix that tells you what kind of address it is and which pool it belongs to. Here's a complete reference:

Of these address types, unified addresses deserve special attention because they represent the recommended way to use Zcash today.

Unified addresses (u1) are the recommended way to use Zcash today. A single u1 address actually contains multiple "receivers" — typically one each for transparent, Sapling, and Orchard pools. When someone sends ZEC to your unified address, their wallet automatically picks the most private receiver type it supports.

This means privacy improves automatically as wallets upgrade. If the sender's wallet supports Orchard, they'll use the Orchard receiver (best privacy). If it only supports Sapling, they'll use the Sapling receiver. And if it only supports transparent transactions, it falls back to the transparent receiver.

From the user's perspective, it's just one address that works with every wallet and always uses the best privacy available.

Understanding pools, addresses, and viewing keys gives you the conceptual foundation. Now here's how all of this shows up in practice when you browse transactions on this explorer.

Every transaction on this explorer is labeled with a type badge that tells you at a glance what kind of privacy it uses. Here's what each one means:

With these concepts in hand, you can read any transaction on this explorer and understand exactly what kind of privacy it uses. The next guide covers Zcash's economic model — how many ZEC will ever exist, how new coins are created, and how development is funded.