The bridged stablecoin of Rand Protocol
One shielded dollar, backed by the USDT and USDC you already hold
Lock USDT or USDC on Ethereum, BNB Smart Chain, Tron or Solana and receive the same amount as zUSD on Rand: digital dollars only the sender and the recipient can see. Redeem to any of the four chains, one-to-one.
| Locked on | Coin | Amount |
|---|---|---|
| Ethereum | USDT | — |
| Ethereum | USDC | — |
| BNB Smart Chain | USDT | — |
| BNB Smart Chain | USDC | — |
| Tron | USDT | — |
| Solana | USDT | — |
| Solana | USDC | — |
| Total locked | — | |
| zUSD in circulation | — | |
Reading the bridge from the explorer… Open the explorer →
- Redemption
- 1 : 1
- one zUSD releases one USDT or USDC, less fees
- Backings
- 7
- USDT and USDC on three chains, USDT on Tron
- Source chains
- 4
- ETH · BSC · TRON · SOL
- New issuers
- 0
- every dollar is Tether's or Circle's, held in custody
What is zUSD?
zUSD is the dollar of Rand Protocol, a chain whose ledger holds no accounts and no balances. Rand has no native dollar of its own, and a private payments network is of limited use without one. zUSD imports the dollars people already use: it is minted when USDT or USDC is locked on its home chain, and burned when that coin is released again.
Public blockchains publish every balance and every payment, which is why businesses keep payroll, supplier terms and trading off them. A zUSD payment is a note in a shielded pool. The network checks a proof that the payment balances and learns nothing else. You keep the viewing key, so your auditor or regulator can still see your records.
There is no new issuer to trust. There is one dependency, and we state it plainly: an independent guardian group confirms deposits and withdrawals on each chain. The risks below set out what that means for a holder.
Lock, mint, transfer, redeem
Each coin is locked in a custody contract on its home chain and attested by a threshold guardian set. Rand mints zUSD against the aggregate, as a note the chain computes from the attested amount. Exit runs the same path backwards.
- 1 Lock
USDT or USDC is deposited into the custody contract on Ethereum, BNB Smart Chain, Tron or Solana, and immobilized there.
- 2 Mint
Guardians attest the lock, with more than two thirds of the set signing. Anyone may submit the attestation, and Rand appends one zUSD note for the recipient.
- 3 Transfer
zUSD moves inside the shielded pool as notes. The ledger records a proof that each payment balances, and its fee. Not the sender, the recipient or the amount.
- 4 Redeem
A burn spends the notes and names a coin, a chain and an address. Guardians attest the burn and custody releases on that leg, one-to-one.
The total USDT plus USDC locked on Ethereum, BNB Smart Chain, Tron and Solana equals the total zUSD on Rand. Transfers inside the pool conserve value, so only a mint or a burn can change the supply, and each one moves a backing's counter by the same amount.
Seven backings, one asset
The asset is shared; the custody is not. Each row below is a separately held balance behind its own contract, with its own counter on Rand's ledger.
| Chain | Coin | Standard | Custody | Trust assumption |
|---|---|---|---|---|
| Ethereum | USDT | ERC-20 | Lock contract | Program correctness ∧ guardian threshold |
| Ethereum | USDC | ERC-20 | Lock contract | Program correctness ∧ guardian threshold |
| BNB Smart Chain | USDT | BEP-20 | Lock contract | Program correctness ∧ guardian threshold |
| BNB Smart Chain | USDC | BEP-20 | Lock contract | Program correctness ∧ guardian threshold |
| Tron | USDT | TRC-20 | Lock contract | Program correctness ∧ guardian threshold |
| Solana | USDT | SPL | Custody program | Program correctness ∧ guardian threshold |
| Solana | USDC | SPL | Custody program | Program correctness ∧ guardian threshold |
One unit of account
Prices, invoices and contracts on Rand are written in one dollar. Nobody has to ask which dollar, or hold two balances to pay two suppliers.
One anonymity set
Every holder hides among every other holder. Separate per-coin pools would each be smaller, and would label every holder by the coin they came in with.
Any leg out
The entry leg does not bind the exit leg. USDT locked on Tron can leave as USDC on Ethereum, provided that backing holds enough to cover it.
What one pooled dollar costs
Issuing one zUSD rather than one asset per source coin is a deliberate trade. The cost is stated here rather than left to be discovered.
zUSD is worth what its weakest backing is worth. If one coin trades below par, depositing it and redeeming a sound one at 1:1 is an arbitrage that runs until the sound backing is exhausted. With separate assets, the loss would fall on that coin's holders alone.
The same path converts USDT to USDC, or one chain's balance to another's, for the price of a proof and a fee. Whichever backing is in demand drains first.
A holder can always redeem into some backing, because supply equals the sum of what is locked. It may not be the coin and chain of their choice. Rand refuses a redemption a backing cannot cover, so a refusal happens on Rand rather than as a stranded release.
A natively issued stablecoin is a direct liability of its issuer. zUSD is a claim on custody held by this protocol, which in turn holds the issuer's coin. That adds the custody contracts and the guardian set to what a holder relies on.
What bounds the first two at launch is rate, not extent: pausers, per-transfer and daily caps, and the release fee slow a drain and make conversion not quite free. There is no standing limit on any one backing's share of zUSD. That risk is accepted for the period before native issuance, which is the period zUSD exists for.
What holds the peg in place
Listed, never created
Only the seven listed backings can mint. A worthless token that merely calls itself USDC cannot acquire a bridged identity, because assets are listed by address and never adopted on first sight.
A counter per backing
The ledger keeps a separate locked figure for each of the seven backings, and zUSD's supply is their sum. A redemption names the backing it draws on, so one custody balance can never be drained on the strength of another.
Burn before release
On the way out the note's nullifier is published first, then guardians attest the burn, then custody releases. The claim is destroyed before the collateral moves, never after.
Caps and a pause
Each backing has a daily mint cap on Rand, 100,000 zUSD on the current testnet. A pause key held apart from the guardian keys can halt minting at once and cannot resume it. Redemptions stay open throughout. The source contracts carry their own pauser and rate caps.
Public custody
The source chains are transparent, so each custody balance is public. Anyone can add up the seven and compare the sum with zUSD's supply, without opening a single note.
Post-quantum guardians
Alongside the ordinary guardian signatures, a post-quantum guardian quorum authorizes governance actions such as resuming a paused mint, so the bridge's controls are built to outlast today's signature schemes.
Asked often
Is zUSD a new stablecoin?
No. zUSD has no issuer of its own and no reserve of bills or deposits. Every zUSD is a claim on one USDT or USDC locked in a custody contract on the chain it came from. It is a bridged representation of dollars that already exist.
Why not wait for Tether and Circle to issue on Rand directly?
Native issuance is a commercial decision taken by a third party on its own timeline, against volume a new chain does not yet have. Issuers deploy where settlement already happens, and settlement needs a dollar first. Bridging breaks that circle. zUSD exists for the period before native issuance.
Why is there no USDC on Tron?
Circle stopped minting USDC on Tron in February 2024 and ended redemption in February 2025. Tron therefore contributes USDT alone, which is why there are seven backings and not eight.
What stays private, and what does not?
Inside Rand, a zUSD payment reveals no sender, recipient or amount. The boundary is public: deposits and releases happen on transparent chains, so the fact and size of a lock or a release are visible there. You keep a viewing key, so an auditor or regulator you choose can still read your records.
What does it cost?
A transfer on Rand pays a small fee in RAND. Redeeming pays a bridge fee on Rand, and the source-chain endpoint takes a 10 basis point release fee. Deposits mint the attested amount.
Can I use it today?
On testnet. The bridge is live on Rand's current test network with all seven backings listed, and the figures at the top of this page are read from it. Testnet assets have no monetary value.
The specification is public
zUSD is specified in the Cross-Chain Collateral section of the Rand Protocol whitepaper: the backing set, the supply theorem, the redemption guard and the pooled-backing remark this page summarizes.