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Bitcoin => Bitcoin Discussion => Topic started by: myself on September 18, 2011, 03:51:28 PM



Title: del
Post by: myself on September 18, 2011, 03:51:28 PM
del


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: Stephen Gornick on September 18, 2011, 07:27:08 PM
there will be situations where you cant check is the address really have that bitcoins or not, so i expect ppl will make offline bitcoins checkers, if the date is on the coin ppl can easily accept or not the bill/coin

I'm trying to understand how having the item marked with the date helps to make it easier (safer ?) to accept.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: johnj on September 18, 2011, 07:32:05 PM
there will be situations where you cant check is the address really have that bitcoins or not, so i expect ppl will make offline bitcoins checkers, if the date is on the coin ppl can easily accept or not the bill/coin

I'm trying to understand how having the item marked with the date helps to make it easier (safer ?) to accept.

Example:

Coin A gets used, thrown on ground.

3 months later, someone finds Coin A.

Someone attempts to pass off Coin A as legit.

---------------

Having a timestamp wouldn't fix anything, but it could cut-down on scenarios such as above.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: geek-trader on September 18, 2011, 07:56:49 PM
That's not how it works.

In order for a coin to be "used", the private key would have to be imported into your wallet.  The get to the private key, you have to remove the hologram from the back.  The hologram is attached in such a way that it is obvious if it has been removed.

So you can tell if a coin has been used or not by just looking at it.

Bitbills have a similar, obvious way to see if they have been used.

The date it was issued has no relevance to anything.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: johnj on September 18, 2011, 08:00:51 PM
That's not how it works.

In order for a coin to be "used", the private key would have to be imported into your wallet.  The get to the private key, you have to remove the hologram from the back.  The hologram is attached in such a way that it is obvious if it has been removed.

So you can tell if a coin has been used or not by just looking at it.

Bitbills have a similar, obvious way to see if they have been used.

The date it was issued has no relevance to anything.

Ahh, I misunderstood.  Thanks for clearing that up.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: TTBit on September 18, 2011, 08:00:54 PM
I don't get it... For it to be 'used' it must be partially destroyed. And I would always check the balance of the address before accepting.

I had a similar thought: Sign each coin address with seccure: http://point-at-infinity.org/seccure/. While this won't eliminate much, it would at least say the address was created by the manufacturer, and cuts down on number of culprits.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: netrin on September 18, 2011, 09:52:28 PM
It is reasonable that there will be situations where you would accept bitcoins without having network access. Indeed, no net access might be precisely why you are using physical bitcoins. From the extreme case of revolution/war, to simply a month out at sea, or up in the Arctic (uh, playing poker or something).

The face value of the coin is dependent upon trusting that the minter did not copy the private key, that the tamper resistant seal is truly irrecoverable, that it can't be x-ray/laser scanned, that the coin is not a counterfeit, and perhaps other attack vectors of which I've not thought.

So while any of those attacks might have occurred before or during your adventure off the grid, there is still piece of mind checking the balance of the public address against an offline block chain.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: netrin on September 18, 2011, 11:56:54 PM
The balances of all addresses will be far less than a gigabyte for quite a while. Today there are 150000 transactions with rarely more than 100 addresses, the majority of which are not unique in the block chain. And the majority of known addresses have a zero balance. Each address and balance is about 50 bytes. I'm guessing, if we drop zero balances, the total list would be less than 100 MB today.

EDIT: The firstbits algorithm, plus simple compression could bring each addresses and balance to about 7 bytes. My new guess is the entire block chain balance sheet could be compressed to 10 MB.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: Elwar on September 19, 2011, 02:04:00 AM
A date would be good though for collector's value sake.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: Stephen Gornick on September 19, 2011, 11:11:49 PM
A date would be good though for collector's value sake.

The transaction when funds were "loaded" to the physical bitcoin has a date and time.


Title: Re: a small suggestion for ppl who make physical bitcoins
Post by: Binford 6100 on September 19, 2011, 11:35:27 PM
plz put on your bills or coins the date when that bill or coins was issued

I'd be more interested in the date when the coins were mined.

example: 17 Dec - birthday - gift idea.

btw I pay premium for bitcoins mined that day, year 2010 5% 2009 3%
PM me if you have any (block explorer is your friend)