How does it stack against nostr:npub17tyke9lkgxd98ruyeul6wt3pj3s9uxzgp9hxu5tsenjmweue6sqq4y3mgl that is also open source and can be built from scratch ?
Discussion
Jade if you operate in air-gapped mode is exactly the same as seedsigner.
I personally don't like this mode because it makes me have the seed available.
If you operate by USB it is like a trezor, but without vulnerabilities, that is, you can not extract the seed due to its multi-signature system that encrypts the seed with the pin and a secret hosted on blockstream servers.
So the seed is stored, encrypted and pin protected on their servers? Need to read about it. Sounds weird.
No, the seed is encrypted with PIN (Local) + secret (Blockstream Server).
The seed is stored locally on the Jade.
What does this do? If you extract the seed from the chip and try to brute force attack it, it will be useless, because apart from the pin, you need the secret (256 bits) stored in the blockstream server.
So they would have to hack also the Blockstream server and have your jade and also know the pin.
On the other hand the blockstream server can not do anything, it is only a shared secret, the blockstream server at no time access to the Jade.
So this needs internet connection to Blockstream servers and they need to work. If they go down? What happens? How do you unlock the secret? Passphrase?
Correct, in case blockstream stops giving service you would only have to restore the seed in another wallet or operate in the other mode that Jade has which is air-gapped (like seedsigner).
There is no risk of loss of funds.
On the other hand you can set up your own server:
https://help.blockstream.com/hc/en-us/articles/12800132096793-Set-up-a-personal-blind-oracle
You also have it on Umbrel:
Pretty cool system.