Send Bitcoin From an Offline Device via Apple’s Find My? A Developer Did

A developer has sent Bitcoin over Apple’s Find My network with a small device that relays Cashu ecash tokens through nearby iPhones. The sending device needs no internet connection during the transfer.

The proof of concept turns the tracking system behind AirTags into an unusual payment channel. However, its builder says it should carry only tiny amounts.

How Bitcoin Moves Over Apple’s Find My Network

A Cashu developer shared the experiment on X, calling it possibly the most absurd way to send Bitcoin yet. Cashu is an ecash protocol that aims to keep Bitcoin payments private through bearer tokens issued by mints.

The open-source code, published on GitHub, runs on cheap ESP32 boards. The device packs a token into Bluetooth signals that imitate lost-item beacons.

Passing iPhones pick up those signals and relay them through Apple’s Find My network, as they would for a missing AirTag. Meanwhile, the recipient pulls those reports with an Apple account and rebuilds the token piece by piece.

A Python script checks the rebuilt token for errors before printing it. Each signal carries only two bits of data, so a typical token needs well over 1,000 broadcasts.

Public Tokens Mean Anyone Can Spend Them

The developer warns that every broadcast token is public. Because Cashu tokens work like digital cash, anyone who recovers one can spend it.

The weak point is the transport itself. According to the protocol notes, the payload carries no encryption, and the IDs needed to look it up are public.

Therefore, the documentation advises sending only giveaway amounts. It adds that delivery is slow, unofficial, and carries no guarantee.

The receiver also taps Apple’s Find My network through an unofficial interface. As a result, the tool could stop working if Apple changes that interface.

The Find My experiment remains a novelty rather than a payment product. Still, it joins other efforts to make Bitcoin payments feel like texting, only this time without internet. Other developers are chasing private Bitcoin transfers on the base layer instead.

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