Wallet Types

Tuck uses a sophisticated multi-wallet architecture to maintain privacy. Behind the simple interface you interact with, several types of wallets work together to break on-chain links and protect your activity. Understanding these wallet types helps you appreciate how Tuck maintains privacy while staying user-friendly.

All of these are ordinary Robinhood Chain accounts: secp256k1 externally owned accounts with EIP-55 checksummed 0x addresses. Nothing about them is unusual to an observer, which is exactly the point.

Use Cases Overview

Each wallet type in Tuck serves a specific purpose in the privacy architecture. Here's when each type is used:

• Main Wallet - Long-term ETH storage in the Tuck Shield pool, cryptographic ownership of private notes, recovery via BIP-39 mnemonic phrase. Never directly receives or sends funds publicly.
• Temporary Wallets - One-time receive addresses for incoming ETH and ERC-20 tokens, swap intermediary wallets, breaking linkability between sender and main wallet. Auto-deleted after 7 days or after processing completes.
• Public Shard Wallets - Store tokens received from external sources (sends, swap inputs), visible on-chain with public transaction history, gas paid by the Tuck relayer and reimbursed from shielded balance.
• Private Shard Wallets - Store tokens from internal swap outputs, maintain privacy for tokens not yet sent externally, gas paid by the Tuck relayer and reimbursed from shielded balance. Convert to public shard when sending tokens externally.
• DApp Wallets - Isolated accounts for dApp interactions, each dApp gets a unique wallet, funded via private transfer from shielded balance, exportable private keys for external connections.
• Bridge Temporary Wallets - Specialized wallets for cross-chain bridges, two-step process (shielded balance → bridge temp → bridge contract or service), prevents the bridge from seeing your main wallet, auto-deleted after the bridge completes.

Main Wallet

Your main wallet is the permanent identity you create using a 12-word recovery phrase. This wallet follows the BIP-39 standard and derives keys along the standard Ethereum path m/44'/60'/0'/0/0, making it recoverable in MetaMask, Rabby, or any other EVM wallet if you ever need to restore elsewhere.

However, your main wallet never directly receives funds or makes public transactions. Instead, it owns your shielded ETH balance inside the Tuck Shield pool — a Groth16 shielded-note contract deployed on Robinhood Chain. When you shield ETH, the main wallet becomes the cryptographic owner of private notes committed to an on-chain Poseidon Merkle tree, spendable only by producing a zero-knowledge proof that reveals a nullifier and nothing else.

Because Robinhood Chain settles to Ethereum and posts data to Ethereum blobs, the shielded pool's state and the anonymity set it protects inherit Ethereum-level data availability.

Temporary Wallets

Temporary wallets are single-use addresses created for receiving funds. Each time you generate a receive address in Tuck, you create a new temporary wallet with a fresh key that has no connection to your main wallet or any previous temporary wallet.

When someone sends you ETH or tokens, they send to a temporary wallet address. Once the funds arrive, Tuck automatically processes them in the background. ETH gets shielded to your private balance, and tokens get distributed across your shard wallets. After processing completes successfully, the temporary wallet is deleted.

Temporary wallets exist for a limited time (7 days). If funds never arrive, the wallet eventually gets cleaned up. If the amount received is too small to shield (less than 0.0001 ETH), the temporary wallet is converted into a shard wallet. This lifecycle ensures you don't accumulate hundreds of unused wallets while maintaining privacy through address non-reuse.

Unlike account-model chains that charge storage rent, Robinhood Chain accounts cost nothing to keep open. An abandoned temporary wallet is free to leave behind — Tuck deletes it for hygiene, not because it costs you anything.

Shard Wallets

Shard wallets are the distributed storage system for your ERC-20 tokens, including Stock Tokens. Instead of holding all tokens in one account where anyone can see your complete holdings, Tuck spreads tokens across multiple independent shard wallets. Each shard is a normal Robinhood Chain account with its own key, unrelated to your main wallet or other shards.

This matters most for tokenized equities. A single address holding tokenized AAPL, TSLA, and an S&P ETF is a readable portfolio with readable cost basis. Split across shards with no on-chain link between them, the same holdings do not reconstruct into one statement.

Tuck uses two types of shards: public shards and private shards. Public shards hold tokens that arrived from external sources — tokens that someone sent you or that you received from a swap input. Private shards hold tokens from internal operations — the output of swaps you executed within Tuck.

This distinction matters for privacy. Private shards remain internal to your wallet until you send tokens externally, at which point those shards are marked as public (since they become visible on-chain). The separation helps Tuck optimize gas costs and maintain stronger privacy for tokens that haven't left your control yet.

By default, Tuck maintains 4 shard wallets per main wallet (3 public, 1 private). The wallet automatically scales the number of shards based on your token holdings, but caps the total to prevent excessive gas costs. When you have too many shards, the consolidation workflow helps merge them back down to an optimal number.

Shard Distribution Strategy

When tokens arrive, Tuck randomly distributes them across your available shards. This randomization is crucial because it prevents patterns from emerging. If Tuck always filled shards in order or used a predictable algorithm, blockchain analysis could potentially correlate activities by observing the distribution patterns.

The distribution ensures each shard gets a meaningful amount while avoiding dust that would be too small to use. For example, if you receive 100 tokens and have 3 public shards, Tuck might split them as 42, 31, and 27 rather than exactly 33.33 each. The slight randomization adds privacy without impacting usability.

Because Robinhood Chain has no per-token account creation cost — an ERC-20 balance is just a mapping entry in the token contract — spreading tokens across shards is dramatically cheaper here than on account-model chains. Distribution costs one transfer per shard and nothing else.

Private Shard Conversion

When you send tokens from a private shard to an external recipient, the private shard becomes visible on-chain through the send transaction. To maintain the privacy boundary, Tuck automatically converts the private shard to a public shard during the send operation.

The conversion process preserves the existing key and tokens — only the shard type changes. The converted shard gets a new public shard index (even numbers: 0, 2, 4, 6...), and Tuck generates a fresh private shard with a new key to replace it (odd numbers: 1, 3, 5, 7...). This ensures you always have private shards available for internal operations while maintaining proper shard distribution.

This conversion happens atomically during the send operation — your token balances are preserved, and the process is transparent. The key stays the same (same address), but the shard is now marked as public since it has visible on-chain activity. This design maintains the privacy boundary: private shards remain internal until exposed, and you always have private shards ready for future internal operations.

Transaction Fees & Relayer

Tuck uses a relayer system to handle gas automatically across all operations. When you send tokens, execute swaps, or perform other transactions, the Tuck relayer submits the transaction and pays the ETH gas upfront. Shard wallets sign an ERC-2771 meta-transaction; the relayer wraps it and pays. This eliminates the need to keep a gas balance in every shard.

After each transaction completes, the relayer is automatically reimbursed from your shielded ETH balance through a Tuck Shield withdrawal. This reimbursement happens in the background — you'll see it as part of the transaction history, but no manual intervention is required.

The reimbursement withdrawal incurs the standard shielded-pool fee (0.0002 ETH + 0.35% of the amount). Tuck's fee estimator accounts for both the network gas and the reimbursement cost when showing you the total estimated fees before you confirm operations.

Robinhood Chain gas has two components, as on any Arbitrum-stack L2: L2 execution gas, which is very cheap, and the amortized cost of posting your transaction data to Ethereum blobs. The estimator quotes both together as a single ETH figure.

DApp Wallets

DApp wallets are isolated accounts you can create for interacting with decentralized applications. Each DApp wallet has its own key and receives funds through a private transfer from your shielded balance. This isolation prevents dApps from seeing your main wallet or linking your dApp activity back to your other transactions.

When you create a DApp wallet, Tuck lets you name it for easy identification (like "Trading Bot" or "Perps"). You can then export the private key to connect this wallet to external dApps, just like you would with a normal wallet. The difference is that this wallet has no on-chain connection to your main holdings.

You can create multiple DApp wallets, each funded separately. This lets you segregate different activities — one wallet for DeFi, another for equity trading, and so on. Each wallet operates independently, and blockchain observers cannot link them together or trace them back to your main Tuck wallet.

When you're done with a DApp wallet, you can send any remaining balance back to your main wallet through a private transaction, then delete the DApp wallet. Or you can keep it active indefinitely for ongoing use with specific applications.

Bridge Temporary Wallets

When you bridge assets off Robinhood Chain — to Ethereum through the canonical Arbitrum bridge, to another chain through an omnichain route, or to ZCash through NEAR Intents — Tuck creates a specialized bridge temporary wallet. This works similarly to regular temporary wallets but is specifically designed for the bridge workflow.

The bridge process privately sends ETH from your shielded balance to the bridge temporary wallet. That wallet then interacts with the bridge contract or deposit address. This two-step process ensures the bridge never sees your main wallet, and blockchain observers cannot link the deposit back to your holdings.

After the bridge completes successfully, the bridge temporary wallet is deleted. If the bridge fails or times out, any refunded ETH is automatically returned to your shielded balance, maintaining privacy throughout the error recovery process.

How Wallet Types Work Together

The power of Tuck's architecture comes from how these wallet types interact. When you receive tokens, a temporary wallet accepts them, then shards store them long-term. When you swap, shards provide the input, a temporary wallet executes the Uniswap trade, and shards (or your shielded balance) receive the output.

Throughout all operations, the Tuck relayer handles gas automatically, maintaining privacy without requiring you to fund every account with ETH. DApp wallets let you interact with the ecosystem while maintaining separation. Each wallet type plays a specific role in the privacy system, and together they create strong protection without requiring you to manage the complexity.

From your perspective, you just see balances and make transactions. The multi-wallet choreography happens automatically behind the scenes. This is the core philosophy of Tuck: uncompromising privacy with familiar UX.