I've been going down the rabbit hole on multisig setups and wanted to see If I could setup a multisig wallet on android using hardware wallets. So far here are my findings:
The only 2 wallets that seem to support hardware wallets at all are MyCelium and Blockstream green. I tried to get both wallets working with a Ledger Nano S Plus and both fail to work, even after I tried the "Bitcoin legacy" app on the ledger. The only other device they seem to support are Trezor, but I don't have a Trezor to test with. AFAIK Nunchuk is the only Android wallet that that supports the Seedsigner, but it doesn't support the Ledger.
If those are currently the only options, it's pretty bleak for multisig on Android; when Sparrow wallet for Android?
Any suggestions?
Thanks!
Have you tried Tap Signer or Cold Card MK4 with Nunchuk NFC tap? Should work like a charm. I have not tried Nunchuk NFC with my MK4 yet, because I scratched off the NFC connection on the PCB and it’s got NFC physically disabled. I do have a Tap Signer and can confirm that it works very well with Nunchuk, whether in a single sig configuration or a multi-sig configuration. My assumption is that the MK4 will work similarly well, since it’s based on the same spec.
When you’re using the Ledger, I assume it pairs to the phone via Bluetooth? I’m quite skeptical with hardware wallets having Bluetooth support, because of the range of Bluetooth, it seems like a bigger attack surface.
when Sparrow wallet for Android?
I remember listening to Craig on a podcast getting asked about if he will create a mobile version for Sparrow, and he said he wants to focus on desktop now and has no intention to work on a mobile phone Sparrow app. He may or may not have change his mind since the interview, but don’t count on a Sparrow phone app anytime soon.
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My assumption is that the MK4 will work similarly well
While the MK4 does have NFC, the signal seems to be much weaker than the Tapsigner's. I can't get mine to talk with Nunchuk via NFC, and this seems like a common problem reading around online.
You can of course still import / export files the old fashioned way via micro SSD, but it would be nice if it worked.
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Thanks for pointing that out. I have no idea that the MK4 NFC signal is weak. Yes you are correct, can always fall back to using PSBT over microSD for Coldcard, provided that the phone also has a microSD slot.
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Thanks for the response everyone. I have a Seedsigner that I was able to get working with Nunchuk. Looks like the ledger just isn't going to work with any Android wallets.
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Currently there are 2 main types of hardware signing devices that work with Android phones (or mobile devices in general):
  • NFC-based: Tapsigner and Coldcard mk4 (and soon the Q1)
  • QR-based: SeedSigner, Blockstream Jade, Foundation Passport, Specter DIY, Krux and Keystone
So we have quite a number of options already and a far cry from just a few years ago when there were none. Check out this thread for examples/guides of how these signing devices work in Nunchuk: https://twitter.com/nunchuk_io/status/1659114136779776001
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