Ethereum security
Every Ethereum request must pass the checks that match its effect.
Transfers, token permissions, messages, and account delegation do not share one approval model. Cryptograph gives each its own watch-side checks.
01
Network and transaction bytes
Apple Watch binds the signing account to the key it derives. It matches the EIP-155 chain ID, destination, value, nonce, transaction mode, and gas ceiling to the signed input. A cross-chain mismatch or unsupported field stops the request.
02
Token amounts and swaps
ERC-20 amounts use decimals from the watch-reviewed asset registry for that contract and chain. Cryptograph refuses unverified token units and swap paths instead of guessing.
03
Typed permissions
Permit2, DAI Permit, and ERC-2612 requests are decoded as spending authority. ERC-2612 review includes the owner, token, spender, amount, nonce, deadline, domain, chain, and verifying contract.
04
Complete message review
Personal-sign requests show the complete UTF-8 message and bind review completion to its byte count and digest. Empty messages, invisible controls, and unreviewable bytes cannot reach approval.
05
Sign-time and broadcast checks
The watch reparses the exact payload and repeats the display contract immediately before key use. After approval, the iPhone checks the nonce and fee state again before broadcast and requires a fresh review if either changed.
06
Approval revocation
Cryptograph lists active ERC-20 and Permit2 allowances with the spender, token, amount, and risk. Permit2 entries also show expiration. A revoke request sets the allowance to zero and receives its own approval on Apple Watch.