Bitcoin Forum

What do you think about this guys http://opendime.com/ ? It seems like it's a project by Coinkite .
They posted about it when they announced about  closing their services here : http://blog.coinkite.com/post/141836920461/time-to-be-your-own-bank

you still have to trust that opendime didnt record the private keys when they created the units.
i dont see the advantages over traditional physical bitcoins

They don't contain any private keys when you first get them and you can also use it offline , you are the one who should create them so It's secure enough If you ask me .

SOUNDS good

but if i enter the exact same random numbers do i end up with the same private key?
if you know what the random numbers where used to create it, could you figure out what the private key is?

Most likely not , I mean if it's case then It would be too easy to crack and take someone else private keys . I suppose it should work like Bitaddress or something like that .

Its hard to beat a simple paper wallet printed from my printer using bitaddress.org or creating a bitcoin vanity address using vanitygen,  ;D  put it this way i wont be moving my bitcoin.

well it wouldn't be easy to figure out some else's pk, but it would mean the creator could know what his pk is without unsealing it.
it sounds interesting.
it makes for a really cool wallet thats forsure.
at the very least its an ultra safe and easy to use paper wallet.

This is a very important advancement for Bitcoin/bitcoin.

it seems to be a pretty interesting thing i might even buy it though i will follow the discussion of the people in here

besides that i always thought i need a physical wallet though i have never found the one that would fit me

This is a funny idea, but not all that useful as far as I can see... And this is definitely not the first physical Bitcoin wallet, lol. It will be something interesting to play with, I guess.


You still have to place trust on how the keys are generated.


At around 8$ each, excluding shipping and excluding the fact it has to be bought in packs of 3 or more, I definitely do not see this as something disposable.

the Lighting network is a  very important advancement for Bitcoin/bitcoin.

why not pay for the car using the blockchain. to me this seems like a round about and pointless form of payment.
this tool is far more compelling as a BTC storage device, not so much a payment solution. IMO

That may be true, but the Bitcoin/bitcoin community needs a way to transact btc in a physical manner
(without phones/computers) that both parties don't know the private keys to.
In theory, the trust has been removed in this product (as long as private key generation is top notch).

For example, this device does what the Casascius Coins could have done,
but this time, the private keys are truly (or purportedly) unknown to anyone other then when it is spent.
With Casascius or other forms of physical btc, the private key is always known to someone.
If I gave someone a paper wallet, and they never swept it, I could have always taken it back.
With this device, that is not possible.

It may be somewhat expensive now and used by a small group of bitcoiners,
but the device and its use will pave the way for new ideas and innovations that adds to
Bitcoin/bitcoin's value and future potential.

Lightning network is not designed to work outside of the network, it is a speed/capacity layer on top of the network.

This device allows users to transact in a physical form that does not rely on trust.

In theory, if Satoshi had all his 1.5 million coins on these devices,
he could sell them all without the blockchain knowing a transaction occurred.

This is not designed to be a storage device for storage, but storage device to physically transact.

its seems like an impractical way to Transact BTC ( in my view nothing beats a good old fashion bitcoin blockchain TX, when it comes to payment.)
its the best form of a Physical Bitcoin wallet i have seen i'll give you that.
there are some big advantages to Transacting BTC this way like you pointed out.

Not sure if  I should be happy or crying.If you can walk with it around,what difference does it makes from the cash ? You might lose it,you might get robbed .I haven't checked out all the features of the USB drive but they haven't specifically mentioned it will be safer as the private keys lies within the hardware . How would it connect without having a wireless connectivity anyway ?

I know you used to sell physical Bitcoin wallets to store keys in. Would you also sell these new wallets if they let third parties start selling them? Doing transactions with physical Bitcoins is a great concept if the trust issues can be completely resolved. I'd like paying in person with a physical Bitcoin if I trusted the system's security.

It has a display or the public address is printed on the device? If not i don't see how you can know how many bitcoins are loaded.

As you can see from the picture,there is no display as such.You just have to plug in the device to your machine and maybe the device driver along with in build software program like their own wallet will be used to deal with addresses.Something like Connect your Usb to your Pc : Open up their wallet,transfer coins into it.Hand over the USB to other guy who can connect it to his PC and retrieve those coins.

This is sounds interesting, never heard something about this before.

Your title is plain wrong, you know that right? Physical Bitcoin wallets have been around for a long time now. Either as paper wallet, coins, token, hardware wallets, etc. The title is also never mentioned in the article itself, so I don't know why you picked it.

I see it like an amazon gift card (loaded with bitcoins), and i think that is expensive. Its more secure but the main problem that i see is the price, and that the person that accept your payment need to plug to a computer to see how many bitcoins it has.

The website title and source code calls it "OPENDIME - World's First Physical Bitcoin Wallet",
but you are correct, it does not exist in the body of the site nor explains the terminology of World's First Physical.
Obviously there have been other physical bitcoin wallets (ex. ledger).

It should probably really be called the "World's First Zero-Trust Physical Bitcoin Wallet".

It's mentioned as you can see on the Title of the page on the browser also I never knew about those "physical coins"

It's a funny concept, but if i understand it correctly, you physically have to break the key in order for it to generate the private key... So every time you use one, you're wasting $8...

we all know coinkite no more give service bitcoin wallet,so it seem like coinkite next project,same as bitcoin phyisical wallet,opendime have good security and nice price about $30 exclude shipping cost.

It's a pity Coinkite cancelled their web wallet for customers but this new project of theirs seems very interesting and promising. The skinny on this Opendime thing is that it's going to be a disposable hardware wallet that you can preload with funds and gift to someone or pay for services and items. According to the details it will be better than a paper wallet because the private keys will be protected inside the device until it's 'broken' and then you can transfer the coins out of the device. You will still need a dedicated Bitcoin wallet to receive the coins into.

If i understand it correctly, it's safer because neither the sender nor the receiver know the private key. So the one paying the coins can not steal the coins after he physically gives the stick to the receiver.
However, if he loses the stick (or gets robbed), the thief can just transfer the coins onto his wallet without any problems.

If you look at paper wallets, it's just the other way around: you need to sweep the paper wallet as soon as you receive it, because the sender can still have the private key, and steal your coins after he gave you the paper wallet... BUT: if you BIP38 encrypted the private key and get robbed: the thief cannot access your coins because your Private key in encrypted.

I still like the device, but i would not give $8 for such a stick if you have to break it to receive the private key...

Coinbase i think was the first Physical Bitcoin wallet

There's always pro's and cons with anything. In this case what if it gets lost, I lost count on how many USB data storage that I lost or misplaced but this will be great for those who knows how to keep everything secured in a nice place and have no trouble in remembering where they last placed this item.

As said before, I also think the blockchain is enough. Just get into the store, send Bitcoins from your phone or whatever and bring the goods.

Here's a "physical" thing that would be interesting: Some kind of Trezor like device with retina scanning and fingerprint scanning capabilities and POS terminals accepting these devices. The device has your keys secured, you insert it in the POS terminal and download address and payment information. You take it out, make it scan your retina, hold it for fingerprint scanning and it signs the keys and creates the transaction. When you connect it to the POS it broadcasts it immediately (that, or it broadcasts it right away from your phone). Either this or the devices generates a private key with the funds and "dumps" it immediately on the POS terminal.

One could argue a device like this could be expensive... Yes, but I prefer it like this: one time cost and multiple usage. I think that paying 8$ for something like this is a bigger premium than paying 200$ for something like what I described.

I understand your point and what you mean, but I still don't think it's worth it to order a few of these to regularly use them. I don't think this would bring people to Bitcoin and help it become something you spend daily. I wouldn't like to spend extra 8$ for having to pay for 50$ worth of groceries.


Yes... And to think people whine about 2 cents transaction fee :D


Casascius was the first.

If the price is really $8 per unit it's not going to be very cheap for a disposable wallet. I wonder if we could use it as a permanent hardware wallet for long-term if we just keep depositing coins to it? I would prefer a USB stick rather than a paper wallet.

If i understand it correctly, you cannot use it as a hardware wallet... You can use it as a cold storage device tough.
You can add coins to it, and keep on adding coins without any problems BUT you cannot access your private key, so you cannot sign a transaction to get part of your coins out. In order to do this, you have to break the stick, and sweep the wallet completely.

Just checked out their website and to be honest I'm not sure about this one. If you give this as payment, even if it's sealed, the guy will still have to check right there and then that the funds are indeed there. It's not like he can just put it sealed in his pocket and be confident he has the money. And if that's the case then using an app on your phone would do just as well. This is one-time use only and costs 8 dollars while a paper wallet is free and doesn't run any risks of malfunction.

I agree the price is a major limiting factor for most users, but I don't think this is really used for everyday purposes.
Right now, it is really just for special cases. But I'm sure in time, the price will come down and a specific market/use will appear.

It is a very good idea but it is a bit expensive so I guess it will be only used for the black market or expensive buys (a car, a house...)

Even then, if i would buy a house or a car with bitcoins, i think i would need a legal contract first... So the buyer and seller would be identified by their id (with a notary), the payment BTC address would be defined,... So their would actually be less worries about not getting your funds.

Especially in the case of buying a house: it doesn't matter what the buyer is doing, the house legally belongs to you, untill the buyer has transferred to coins to the address given on contract. So there would be no use for a single-use stick IMHO.

The only "real" reason i would ever use this, is cold storage... But even then, i'd rather use a BIP38 encrypted paper wallet.

That being said: it's a nice gadget, and i'm pretty sure somebody will put it to good use :)

Can anyone confirm what will happen to the private keys after you break the seal and activate the device? I think they will be generated into the USB stick and stay there in a text file or a QR code so they should be reusable and not only a one time thing right? $8 for a disposable wallet is too much but if it can be reused as a cold storage it could make a great cheap little device for storing Bitcoins.

I think it's secure enough if we create our own private key.
besides, physical bitcoin can't be stolen online, at least we can save it in secure place we had.
those are the advantages, aren't they?

The Answer is in the FAQ ;)


So basically, the private key is in a plain-text ASCII .txt + a QR-code image (png, gif, jpeg?) once the key is "broken"
In other words: you could re-use it, but i would advice against it, because once broken, the stick offers less protection than an encrypted paper wallet, or a desktop wallet with a passphrase.

casascius bitcoin is the first one i think so.. it is a collectible coin packed by real bitcoins inside.. each coin has its own bitcoin address and private key underneath the hologram..

I do not see the logic in this. If you connected the device and moved coins to it and then have to give this device to someone else to receive that value, the private key will be compromised and the device be rendered void. Instead of paying a few cents for one transaction, you would be paying $8 for the device and only be able to use it securly for one transaction. How can this be a solution to provide a expensive device that can only be used once? ^clueless^

That's not the really first physical bitcoin wallet, Trezor and the like are also hardware like wallets that are intended to be used for multiple transactions and should be as secure as an offline machine, still find this idea interesting though :)

Here is a video https://www.youtube.com/watch?v=LK5G5jAzoyk

So it's like a loaded Casassicus coin, disregarding it's collectors value.

You can pass them on, load them up, or spend them. Wouldn't a paper wallet be the first physical wallet? This souls be more of like, "the first physical bitcoin note"

I'm finding the uses for this to be fairly minimal. Maybe I'm just not fully understanding it. Why wouldn't I just give someone a paper wallet if I didn't want to do a transaction, but wanted to hand over funds (let's say to a car dealer). Either way they would want to sweep the funds and get confirmations before releasing the vehicle to me.

This project is pretty nice but the title is wrong indeed, I think if this project will grow it has a good point of succeeding for sure.
I hope this project will keep alive because I believe in it for sure.

I agree it should be titled  the first physical bitcoin note  as the previous poster said it should be to not confuse with the other ones.

i have no idea about this. i dont know about the physical wallet of bitcoin, but how can a person keep the bitcoins in physical wallet. is it possible to keep digital currency in a physial wallet.

First physical wallet... not... There were loads of other hardware wallets before this one.... I think this can rather be described as a disposable hardware wallet. I do not see why USB firware cannot be

infected by this? {BadUSB exploit} If this was used more than once this would have been a problem. Give me a paper wallet or a Trezor any day of the week, over this wallet. I am all for making things

easier, but this is a waste in the most terrible way possible. {use once and throw away?}