Are there any hardware privkey/pubkey generators out there?

I don't mean hardware wallet like Trezor but simply a device that is non-programmable, and not network connectable but will generate key pairs (+ the associated address would be handy but that could be done in software on only the pubkey without too much risk?) at the push of a button.

I'm wondering if this is one way to create a paper wallet and have it receive a number of BTC:

1.Generate a privkey/pubkey pair

2.Write the privkey down, duplicate it and store the copies safely. I guess this could potentially be split into pieces and stored in several separate places so that breach or loss of one does not give away the full privkey or lose the information needed to recreate it (like a paper RAID array implemented with three familiy members?) [and write recovery instructions in your testament]

3.Generate the bitcoin address associated with the pubkey (not so risky, afaict)

4.Receive the payment at this address

Until it comes to spending the BTC (which could be quite some time in the future) there would be no need for a software wallet, and certainly no need to use an online key generator.

In the absence of a hardware key generator I suppose downloading trusted code from sourceforge or somewhere and running it yourself on a non-networked computer is pretty much as secure?

(I realize rolling dice is fine to generate a privkey but the associated pubkey pretty much has to be done in code somewhere, no?).

Does this sound feasible?

darren

Posted 2014-12-12T03:15:11.123

Reputation: 107

Answers

There are no devices I know of which are dedicated to nothing but generating secp256k1 key pairs. I suspect there never will be---that's a super-niche market possibly consisting of just you. Moreover, I think you should be suspicious of any hardware designed to generate private keys for Bitcoin: corrupting such hardware to produce predictable keys could be highly profitable---at your expense.

In general, messing around with private keys directly has a high probability of ending in lost bitcoins. A $50 USD used netbook from eBay to use as an offline signing-only wallet will be much easier to use and at least as secure as any system you think up yourself, provided you choose a secure wallet.

David A. Harding

Posted 2014-12-12T03:15:11.123

Reputation: 10 154

thanks, I see your point. That said Trezor is hardware desgined specifically to generate key pairs with a little more added on, is it not? The brand has much to lose if it's found out that something untoward has happened but that could be nothing compared to the gains. I have a Trezor and there's no reason to believe the company is anything but honest but I don't see a that big of a distinction between the two cases. – darren – 2014-12-12T04:14:55.263

The offline signing-only wallet sounds useful, thanks for the pointer. We're still putting our trust in someone by selecting the "secure wallet" to use but I can see the logic. – darren – 2014-12-12T04:21:26.403

Trezor's main purpose is secure signing, and it mostly derives key pairs from a seed rather than generating them from a random number. I have reasonable trust in the public faces of Trezor, but I don't know anything about the people who designed the hardware, manufactured the hardware, or delivered the hardware---and any one of them could've changed the specs in a way that's very hard to detect. – David A. Harding – 2014-12-12T04:22:27.993

There is Piper Wallet.

And Bitfrore is in the works.

Both are self-contained devices which generate and print private key and address pairs.

Chuck Batson

Posted 2014-12-12T03:15:11.123

Reputation: 565

I've read that Verso is "... also working on a system to allow users to create the public/private key(s) offline for security." (see https://axablends.com/merchants-accepting-bitcoin/bitcoin-wallets/verso-cards-bitcoin-cold-storage-for-everyone/), though I can find nothing on the Verso website yet (12/11/14) to back this up (not saying I would use it!)

https://versocards.com/ - their cards look interesting and don't require two computers but instead use a card encoded with your private key that is scanned by a mobile phone app that actually recreates the key to use for spending. It appears to be a single address/pubkey/privkey system though, from what I can tell.

offline capable wallets:

https://bitcoinarmory.com/

https://electrum.org/index.html

darren

Posted 2014-12-12T03:15:11.123

Reputation: 107