Recent “LEDGER Recovery service” drama made me wonder about cold wallets options for cardano. I think that the best and safest solution would be an open source software wallet with cold storage feature like ELECTRUM for BTC. That for instance would allow me to use my own old laptop or smartphone without internet connection as cold hardware wallet. It would be enogh to sign transactions and output it as QR code or something. I googled to find such wallet for cardano but didn’t found anything.
Is wallet like that exist?
If not, is someone planning to develop it?
Here is one by our own community member @johnshearing which I believe can be adapted to Cardano storage if not done so already & supporting air-gapped QR code signing:
I developed something with a little different approach, finding the USB-drive form factor appealing and wanted to see how we could surpass Ledger functionality while keeping the footprint small (today I find it works best with an old SATA SSD drive + SATA-to-USB cable). Instructions centre around Cardano Stake Pool operation, with no Internet access & manual key transaction signing (a “cold” environment), though these days I mainly use it as a second, more secure boot environment with an Internet connection (“cool” rather than cold) to support browser-based wallets:
It was an earlier debacle, also with Ledger, that prompted me to publish this material in that same month (December 2020). There had been a big customer leak at the time with dim prospects for customer privacy going forward, with ongoing questions about whether hardware wallets really provide “non-custodial” security at all: Frankenwallet > But I can afford a hardware wallet…
Generally if you want something whose security level is fully known to & auditable by you, you will have to either build it yourself or have someone you trust (individual or commercial) build it for you. Otherwise you’ll always be stuck with another black box and another back door.
Yes, you’re right. TxBuilder in eternl allows you to download unsigned transaction as a file and then you can import and sign it offline on other device under ‘Send’ and ‘Import’ tabs respectively. Finally you can import and submit signed transaction in eternl on online device.
In eternl there is also a possibility to import wallet as “Public account key (read only wallet)” - that would be on online device.
So it seems there is almost all what is needed. I wonder whether it is possible to interact with dapps with this method. I don’t see download button for unsigned transaction that is created by dapp.
Thank you very much for pointing out that feature in eternl.