Privacy considerations for WETH to WBTC
Where offered, Private Route is designed to reduce an obvious direct association between the sending wallet and received assets; it does not make WETH on Scroll or WBTC on Base activity anonymous or invisible. Scroll exposes account history, token approvals, contract calls, logs, gas funding, amounts, and timing under its own chain identifier. It is a bytecode-compatible zero-knowledge EVM rollup that proves batches to Ethereum. Scroll inclusion and Ethereum proof settlement are distinct, and its token contracts must be verified independently from L1. Base exposes account history, token approvals, contract calls, logs, gas funding, amounts, and timing under its own chain identifier. It is an OP Stack optimistic rollup that batches L2 execution and settles to Ethereum. The same 0x wallet can display different balances on Base and Ethereum, and a token contract on one chain does not identify the representation on the other. WETH is a contract wrapper for ETH. It can be transferred as a token but cannot replace the native gas balance required by the network. WBTC is a custodial tokenized Bitcoin representation on smart-contract networks. Its transfers use token contracts and approvals rather than native Bitcoin inputs and outputs. Wrapped assets depend on a token contract and a separate underlying asset model. Wrapper interactions, approvals, unwrap activity, and the destination representation can remain public and may create additional association points. Identity-verification requirements are separate and must be checked in the live flow.
What remains visible on Scroll
Scroll exposes account history, token approvals, contract calls, logs, gas funding, amounts, and timing under its own chain identifier. It is a bytecode-compatible zero-knowledge EVM rollup that proves batches to Ethereum. Scroll inclusion and Ethereum proof settlement are distinct, and its token contracts must be verified independently from L1. ETH is the native gas asset for Scroll. Reusing the sending address, approval pattern, or recognizable amount can preserve source-side context.
What remains visible on Base
Base exposes account history, token approvals, contract calls, logs, gas funding, amounts, and timing under its own chain identifier. It is an OP Stack optimistic rollup that batches L2 execution and settles to Ethereum. The same 0x wallet can display different balances on Base and Ethereum, and a token contract on one chain does not identify the representation on the other. Receiving-address reuse, immediate consolidation, and later transfers can create destination-side associations.
Scroll source role versus Base destination role
A Scroll source executes in the zkEVM and is later included in a proof batch to Ethereum; Scroll contract identity must be verified independently. Those source-side events remain visible. A Base receipt belongs to the Base L2 balance and token contract, not Ethereum L1; later activity needs ETH specifically on Base. That receipt and later destination activity remain visible.
Scroll and Base keep separate account histories
The same-looking 0x wallet syntax does not combine the two ledgers. A Scroll source executes in the zkEVM and is later included in a proof batch to Ethereum; Scroll contract identity must be verified independently. WETH leaves through a wrapper contract and needs native chain gas. A WETH token balance cannot pay the gas required to submit its own transfer. A Base receipt belongs to the Base L2 balance and token contract, not Ethereum L1; later activity needs ETH specifically on Base. WBTC arrives as a wrapper-contract token and must not be sent onward to a native Bitcoin address without an explicit unwrap or bridge path. Rollup inclusion and settlement can also expose different timing milestones.
Wrapper activity can add another association point
Wrapped-token approvals, transfers, and later unwrap activity are public contract events. WETH leaves through a wrapper contract and needs native chain gas. A WETH token balance cannot pay the gas required to submit its own transfer. WBTC arrives as a wrapper-contract token and must not be sent onward to a native Bitcoin address without an explicit unwrap or bridge path.
WETH wrapper and unwrap evidence; WBTC custody-wrapper evidence
WETH approvals, wrapper transfers, and later unwrap activity remain visible contract events. A private route does not turn WETH into an unrecorded native ETH balance. WETH leaves through a wrapper contract and needs native chain gas. A WETH token balance cannot pay the gas required to submit its own transfer. Those source events remain public. WBTC approvals, wrapper-contract transfers, custodian-linked mint or burn context, and later unwrap activity remain public. No native Bitcoin UTXO is hidden by a WBTC token transfer. WBTC arrives as a wrapper-contract token and must not be sent onward to a native Bitcoin address without an explicit unwrap or bridge path. The receipt and later destination use remain public.
What Private Route changes—and what it does not
Private routing can reduce an obvious link between two EVM accounts, but source approvals, gas, logs, destination contract or native receipt, and later activity remain on separate chain histories. Sequencer and settlement timing can add correlation evidence. A Scroll source executes in the zkEVM and is later included in a proof batch to Ethereum; Scroll contract identity must be verified independently. WETH leaves through a wrapper contract and needs native chain gas. A WETH token balance cannot pay the gas required to submit its own transfer. A Base receipt belongs to the Base L2 balance and token contract, not Ethereum L1; later activity needs ETH specifically on Base. WBTC arrives as a wrapper-contract token and must not be sent onward to a native Bitcoin address without an explicit unwrap or bridge path.
Verification and provider policy for this exact route
The provider must support the exact L2 direction, asset contracts, amount, and region. Rollup support and privacy routing do not imply that identity verification, account, or custody requirements are absent. A Scroll source executes in the zkEVM and is later included in a proof batch to Ethereum; Scroll contract identity must be verified independently. WETH leaves through a wrapper contract and needs native chain gas. A WETH token balance cannot pay the gas required to submit its own transfer. A Base receipt belongs to the Base L2 balance and token contract, not Ethereum L1; later activity needs ETH specifically on Base. WBTC arrives as a wrapper-contract token and must not be sent onward to a native Bitcoin address without an explicit unwrap or bridge path.
