Public and shielded HYDD
Public HYDD sits in your wallet like any ERC-20. Shielded HYDD sits in the vault as shares. Shares are redeemable for a growing amount of HYDD because trading fees are added to the vault without creating new shares.
Stealth addresses
A stealth address is a one-time address that a sender computes from your public stealth meta-address and a random ephemeral key. Only you, with your viewing key, can recognise it as yours; only you, with your spending key, can control it.
Announcements
When someone pays a stealth address, the vault emits an ERC-5564 Announcement event carrying the ephemeral public key. Your app scans these events and finds the payments addressed to you.
Denominations
Stealth payments move in fixed sizes — 1,000, 10,000, 100,000 or 1,000,000 HYDD — so payments of the same size look alike.
Signed operations
Stealth addresses usually hold no ETH. Instead of sending a transaction, you sign an EIP-712 message and anyone (a relayer, or the router) submits it, earning a small fee in HYDD shares.