Bitcoin · BTC
Keep your Bitcoin keys off your phone.
Your iPhone can prepare a Bitcoin transfer. You approve it on Apple Watch, where the signing keys stay.
Current support
Bitcoin in Cryptograph.
Native assets, token standards, and connection methods differ by network.
- Native asset
- Bitcoin (BTC)
- Addresses
- Native SegWit receive and change addresses derived with BIP-84.
- Transfers
- Send and receive BTC. Every outgoing transfer requires approval on Apple Watch.
- WalletConnect
- BIP-122 transfer requests, PSBT signing, and account-address discovery.
On Apple Watch
What you approve.
Bitcoin selects previous outputs, calculates a fee, and returns change. Apple Watch establishes that complete plan before approval.
- 01The recipient and amount come from the transaction data the watch will sign.
- 02Apple Watch calculates the exact selected inputs, outputs, fee, and change.
- 03Every change output must return to an address derived for your wallet.
- 04The finished signed transaction must match the approved plan before it leaves the watch.
Network-specific security
The watch proves the Bitcoin plan before and after approval.
A transaction summary can hide a larger miner fee or redirect the change output. Cryptograph does not use the iPhone summary as the signing authority.
For PSBTs, Apple Watch reads every output and the total fee. A multiple-output request without verified change is blocked.
Current limit
Bitcoin message signing is not currently available through WalletConnect.
Cryptograph supports BIP-122 transfers and PSBT requests. Message signing will remain unavailable until the message can be reviewed and signed under the same watch-side rules.