Zcash is one of the few chains where privacy is a choice you make per transaction. Two of its address forms publish everything to the block explorer; two encrypt it. The difference is visible in the first characters of the address, and it decides whether your swap leaves a readable trail.
The four prefixes
- t1 and t3 - transparent. Amounts and addresses are public, exactly as on Bitcoin.
- zs1 - shielded (Sapling). The sender, the receiver and the amount are encrypted.
- u1 - unified. A single string that carries a shielded receiver; current Zcash wallets hand out this one by default.
- zc - Sprout. The original shielded pool, now retired: the protocol no longer lets value enter it.
What a transparent address reveals
On a t1 or t3 address the chain records the same things Bitcoin does: which address paid, which address received, and how much. Anyone can read it later, and anyone can link the two ends. That is not a flaw in Zcash - transparency is one of its two modes, and it exists so the coin can move through venues that cannot handle encrypted notes.
What a shielded address hides
In the shielded pool the amount and both ends of the transfer are encrypted. An observer sees that a transaction happened and what fee it paid, not who sent what to whom. Only someone you hand a viewing key to can read the detail, which is exactly why a shielded balance is worth keeping shielded.
Where privacy leaks anyway
The usual leak is not the address form - it is the round trip. Move funds out of the shielded pool to a transparent address, do something with them, then shield them again, and the amounts and timing on both transparent legs can be lined up. Most exchanges force exactly that, because they can only pay a t1 address. The shielded pool protects what is inside it; every step outside it is public again.
Sprout (zc) can no longer be paid
Sprout was Zcash’s first shielded design, and it has been closed to new value since the Canopy upgrade. A zc address is not merely old: the protocol will not let anyone, us included, move value into it. If a wallet still shows you one, switch to a u1 or zs1 address before you ask anyone to pay you.
Swapping without unshielding
This is where the distinction stops being academic. We pay Zcash out to shielded u1 and zs1 addresses directly from our own Zcash wallet, so the payout does not have to touch a transparent address to reach you. On the way in, an order publishes both forms: a transparent t1 address as the main one, because exchange withdrawal forms and multi-chain wallets can only send there, and a u1 address underneath it for Zcash-native wallets. Both belong to the same order and either one credits it, so a shielded sender never has to unshield first. The Zcash page states how many confirmations we wait for.
