OpenDime wallet questions

[Hulton]

Hey! I have a few questions for OpenDime wallet users.

After unsealing the USB - can I transfer any more BTC into it or am I forced to withdraw everything immediately?

Can I withdraw a specified amount of BTC or I have to transfer everything I have on it?

Thanks in advance

[HCP]

You *could* transfer more coins to the associated address, as the coins are stored on the blockchain, not on the device itself... and the blockchain has no knowledge of whether or not the OpenDime device is sealed or unsealed or even that the public key/address that the coins are being assigned to are even on an OpenDime device

You *could* also transfer just a small portion... or all of it... or none of it...

The main reason NOT to do any of these things is security... once you pop the seal, the private key is then able to be accessed. While perhaps unlikely, it is not impossible for malware to be able to access the private key once the OpenDime unsealed and connected to an infected computer.

Also, as far as transferring less than the full amount, you run the risk of losing bitcoins into unknown "change" addresses if you are not very careful about how you go about constructing the transactions to withdraw smaller amounts. It's possible, depending on the wallet you use to "spend" the contents of the OpenDime, that the leftover change will end up going into a change address that you do not have the private key for and are therefore unable to spend the coins from! Ref: http://bitzuma.com/posts/five-ways-to-lose-money-with-bitcoin-change-addresses/

[Hulton]

Thanks! I don't think the leftover funds would be transferred to change adress..

In the OpenDime FAQ, they say there's an "balance.py" program included that allows you to check balance and TRANSFER the funds without unsealing the device. How does that work? Doesnt make much sense to me.

[HCP]

No... it lets you check the balance of a sealed device... and if the device is unsealed, you can also send funds:

# Python code to check balance and send funds if unsealed.
#
#   python balance.py
#
# That will show the current balance for this Opendime by asking a
# number of blockchain servers on the public Internet. Then, if this
# Opendime is unsealed, it will also offer to move all funds to
# another bitcoin address.

You cannot get funds out of an OpenDime if it is sealed, as the private key is not known by anyone (even the person that first setup the device with funds) and cannot be viewed until the device is unsealed.

[Hulton]

I see, thanks!

So after unsealing I can use most of the "hot" wallets (like electrum), import the private key and spend a specified amount of the funds from OpenDime, right?

[HCP]

Theoretically yes... but do pay attention to what outputs are being generated before you sign/broadcast the transaction... make sure that any change generated (ie. you're not spending the full amount) is being sent to an address that you have the private key for...

If that private key is the ONLY key in your Electrum wallet (ie. you created a new wallet and imported just the OpenDime private key) then I *believe* it should send the change back to the OpenDime address... but I've only tested this on TestNet addresses/transactions. Suggest you use the "Preview" button prior to sending and make sure the output address with change is the same as the input address

[Lincoln6Echo]

Is the storage for the private key in some way redundant? So if one memory module fails there is still another chip that holds a copy.

Or isn't that a likley event when using opendime as a bitcoin wallet for years?

[allyouracid]

Is the storage for the private key in some way redundant? So if one memory module fails there is still another chip that holds a copy.

Or isn't that a likley event when using opendime as a bitcoin wallet for years?

I just came here to ask the same question. Been searching the internet, but this topic doesn't seem to be covered anywhere. I wonder why.
So, as the OpenDime is an electronic device, it's vulnerable to certain things (corrosion, components fail due to temperature etc). If someone just uses the public key to fill his OpenDime over a few years without ever plugging it into the compuer, and then decides to cash out because Bitcoin has just reached 1.000.000 USD and then, after "breaking" free the private key, realizes that some component on the device died because of age... what does he do then?

[TryNinja]

Is the storage for the private key in some way redundant? So if one memory module fails there is still another chip that holds a copy.

Or isn't that a likley event when using opendime as a bitcoin wallet for years?

I just came here to ask the same question. Been searching the internet, but this topic doesn't seem to be covered anywhere. I wonder why.
So, as the OpenDime is an electronic device, it's vulnerable to certain things (corrosion, components fail due to temperature etc). If someone just uses the public key to fill his OpenDime over a few years without ever plugging it into the compuer, and then decides to cash out because Bitcoin has just reached 1.000.000 USD and then, after "breaking" free the private key, realizes that some component on the device died because of age... what does he do then?

There is an "What is the expected lifetime of the device?" section on their FAQ, which says:

Like most electronic devices, if stored properly it should last decades.

The expected reliability of the part that stores the private key as described on the ATSAMD21E17 datasheet is between 25-100 years [page 1014]

Source: https://opendime.com/faq

If it breaks before that date, your coins are most likely gone.

[DaveF]

The expected reliability of the part that stores the private key as described on the ATSAMD21E17 datasheet is between 25-100 years [page 1014]
Source: https://opendime.com/faq

If it breaks before that date, your coins are most likely gone.

Although I do have some BTC on OpenDimes it does kind of scare the crap out of me for just that reason.

Plug it into a bad USB port and something fries. Poof it's gone.
Some weird EM field from some other device corrupts something. Poof it's gone.

Etc.

But.... on the same note that loaded physical coin you have in your display cabinet because it looks nice. Small fire due to an electrical short in the lights on top of the cabinet.
Poof it's gone.

You have to do a risk analysis on how much you are willing to loose vs. how you want it stored vs. a few other things and come up with your own comfort level.

-Dave

[DaveF]

From the theory of can't hurt to ask the people who built it, I just emailed coinkite / opendime letting them know about this thread here. Let's see if they respond.

-Dave

[DaveF]

What I got back was:

Hi Mining,
Thanks! Just read it, you guys figure out

-Coinkite Team
On Mon, 17 Jun at 8:01 AM , Mining <mining@-------> wrote:
 
Discussion popped on Bitcointalk about opendimes. https://bitcointalk.org/index.php?topic=2254653 don't know if you want to chime in.

-Dave

[HCP]

So basically... it *should* be good for at least 25 years from a data retention point of view.

The trick is finding a way of keeping it safe to prevent accidental loss, that also ensures that it is secure. Just like you need to with paper wallets, seed backups etc.