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Topic: bitcoincard.org - page 10. (Read 29251 times)

legendary
Activity: 1078
Merit: 1000
Charlie 'Van Bitcoin' Shrem
June 04, 2012, 11:53:25 AM
We will be blogging about it in real time!
hero member
Activity: 868
Merit: 1000
June 04, 2012, 11:48:32 AM
Can't wait Cheesy
legendary
Activity: 1008
Merit: 1021
Democracy is the original 51% attack
June 04, 2012, 11:43:27 AM
Only days away from a report on this Bitcoin Card... stay tuned! Wink
legendary
Activity: 1708
Merit: 1007
June 04, 2012, 11:31:38 AM
That's a pity. nLockTime could have interesting applications.

It might yet.  It's still part of the protocol, feel free to dive in and code it into a client fork; and we shall see where that takes us.
hero member
Activity: 630
Merit: 500
June 04, 2012, 10:44:01 AM
That's a pity. nLockTime could have interesting applications.
donator
Activity: 1218
Merit: 1079
Gerald Davis
May 30, 2012, 02:19:28 PM
But miners should at least "respect" blocks that contains it, right? Or is nLockTime just an idea for a future version of the protocol?

They don't respect it currently.

To "replace" a tx requires making a new tx with a higher sequence value.  All tx currently use a sequence of MAX_INT.  Miners won't see anything else as valid.

So if you make a nTimeLock tx w/ sequence MAX_INT it is "useless" as it can never be replaced (there is no valid sequence value higher).  If you make anTimeLock tx w/ a sequence value other than MAX_INT it will never make it to the memory pool as it won't pass validation by current rules.
hero member
Activity: 630
Merit: 500
May 30, 2012, 12:26:52 PM
Is the nLockTime parameter fully implemented? I mean, will miners recognize it and all? I ask that because I haven't seen a single client making use of it so far. (sending transactions with nLockTime)

No.  I don't believe it is supported by any client/miner yet.

But miners should at least "respect" blocks that contains it, right? Or is nLockTime just an idea for a future version of the protocol?
donator
Activity: 1218
Merit: 1079
Gerald Davis
May 30, 2012, 12:22:38 PM
Is the nLockTime parameter fully implemented? I mean, will miners recognize it and all? I ask that because I haven't seen a single client making use of it so far. (sending transactions with nLockTime)

No.  I don't believe it is supported by any client/miner yet.
hero member
Activity: 630
Merit: 500
May 30, 2012, 12:15:19 PM
On edit:
WAIT WAIT WAIT
I think it could work IF the wallet regenerates the "recovery tx" (nLockTime) after every spend.  This would be a pretty cool concept even for "normal" wallets.

That's what I meant. Wink

Is the nLockTime parameter fully implemented? I mean, will miners recognize it and all? I ask that because I haven't seen a single client making use of it so far. (sending transactions with nLockTime)
donator
Activity: 1218
Merit: 1079
Gerald Davis
May 30, 2012, 08:55:07 AM
I just thought, the problem I mentioned above could be solved without having to backup the keys (in case the addition of a backup feature would represent a security risk).

The bitcoincard could generate a "time locked" transaction (nLockTime) to an address in control of the owner.  Say, 6 months in the future. If the owner remains in control of the money, before the deadline he can revert the transaction to himself, and send a new time locked one. If the card is lost/destroyed/stolen, and supposing it requires a code for spending, then the owner only have to wait for the time locked transaction to unlock.

Well the blockchain doesn't work that way.  It would be useful but only for cold storage.

Remember the blockchain doesn't use "account/address balances" that is merely an abstraction for the end user.  All tx inputs are unspent prior tx outputs (except coinbase txs).

An example might help:
Say you have a wallet w/ single address abc with value of 100 BTC.  It comes from a single unspent tx (A).

from blah 100 BTC to Address abc  <- unspent output A.

Your wallet "knows" it is worth 100 BTC because it scans for all unspent outputs sent to Addresses it has private keys for (in this case only this one unspent output A for address 123).

Now you could create an nLockTime tx
Input:  unspent output A
Output: Recovery Address
Options: nLockTime (~ 6 months - nLockTime is in blocks)

The problem is as soon as you spent a single cent from this wallet.  "Unpsent" tx A becomes spent tx A and the "recovery" tx becomes invalid.

On edit:
WAIT WAIT WAIT
I think it could work IF the wallet regenerates the "recovery tx" (nLockTime) after every spend.  This would be a pretty cool concept even for "normal" wallets.

Example:
Wallet has unspent output A.
Wallet makes recovery tx (nLockTime) using outputA and publishes to network.

User spends some coins using output A, creating unspent output B (change)
Wallet makes recovery tx (nLockTime) using outputB.
Wallet broadcasts both to network simultaneously.


User spends some coins using output B, creating unspent output C (change)
Wallet makes recovery tx (nLockTime) using outputC.
Wallet broadcasts both to network simultaneously.

User receives coins (a new unspent output D)
Wallets makes a recovery tx (nLockTime) using unspent output D.
Wallet broadcasts new recovery tx as soon as it receives "unprotected" coins.



hero member
Activity: 630
Merit: 500
May 30, 2012, 03:35:46 AM
I just thought, the problem I mentioned above could be solved without having to backup the keys (in case the addition of a backup feature would represent a security risk).

The bitcoincard could generate a "time locked" transaction (nLockTime) to an address in control of the owner.  Say, 6 months in the future. If the owner remains in control of the money, before the deadline he can revert the transaction to himself, and send a new time locked one. If the card is lost/destroyed/stolen, and supposing it requires a code for spending, then the owner only have to wait for the time locked transaction to unlock.
hero member
Activity: 630
Merit: 500
May 30, 2012, 03:25:03 AM
3) security - maybe through obscurity but most of the smartphones that COULD run a BTC transaction are running Android and would be more susceptible to a hack then the bitcoincard.  Malware may be on as much as 20% of all Android phones making it a bad place for the masses to store BTC.

True, a bitcoincard would be much harder to hack, but it's easy to lose it, have it accidentally destroyed, or stolen together with your belongs. And if I understood it correctly, you cannot backup the keys. So, in what concerns safety/security, you should deal with it just like you deal with a smartphone wallet: do not put more money in it than what you can afford to lose.
legendary
Activity: 1470
Merit: 1002
Hello!
May 28, 2012, 08:42:33 PM
When can I pre order 50
legendary
Activity: 980
Merit: 1004
Firstbits: Compromised. Thanks, Android!
May 27, 2012, 03:01:59 PM

1) cost - no smartphone I know of will be able to do a BTC transaction without costing over $100 or requiring a contract.  I assume bitcoincard will be under $50


It will be far under $50 Wink

Really??
That would be totally awesome. Can't imagine a better tool for blowing away my bitcoin-sceptical friends. I would immediately order a couple of units at a sub-10 btc (lets quote prices in real money!) price point.
Can't wait for june 10-15 to come round...

The workshop starts on the 11th!

legendary
Activity: 2198
Merit: 1311
May 27, 2012, 02:52:21 PM
Quote
How are you going to do a Bitcoin tx when neither party has access to the internet?

Do some research on the matter.


No thanks.

Quote
Quote
No reason for a smartphone to have internet when you don't want it to.  "Airplane mode" disables all radios at the device level.  Kinda hard to be online when you have no signal. Wink

Unless you intend to carry a second phone to actually make calls, texts or use the Internet while mobile; you're going to turn that mode off eventually.  I'm not concerned about a live hacker taking my money, I'm concerned about a worm or virus that steals android wallets.  That only takes a few seconds.

So what is the difference between 1 phone + 1 phone being used as a dedicated bitcoin device  vs 1 phone + dedicated bitcoin device.

My point is the hardware already exists.  It is called a smartphone.  It has everything you need including connectivity and software.

For most casual users a single device is fine for the paranoid just carry two.  

The aim here is to provide (maybe a niche but I think not) a device that has better properties then a smartphone for bitcoin.

Quote
1) cost - no smartphone I know of will be able to do a BTC transaction without costing over $100 or requiring a contract.  I assume bitcoincard will be under $50

But I already have a smartphone, and I'd be willing to be that most bitcoin users do too.

Quote
2) size - no smartphone fits in the wallet

No, but it fits in my pocket, where I happily carry it around with me everywhere, everyday.

Quote
3) security - maybe through obscurity but most of the smartphones that COULD run a BTC transaction are running Android and would be more susceptible to a hack then the bitcoincard.  Malware may be on as much as 20% of all Android phones making it a bad place for the masses to store BTC.

This, I think, is a valid concern.  Right now, my solution is to use my phone (blockchain.info iPhone app) to keep as much money as cash I would carry in my physical wallet - so not much.  For big online purchases, I'd rather do them from my home computer, where I have access to more money via Armory offline wallets, etc.
hero member
Activity: 743
Merit: 500
May 27, 2012, 02:47:19 PM
 Just one idea ,what about to open small BitcoinCard company in GLBSE and support the project? The card have huge potential.
legendary
Activity: 1078
Merit: 1000
Charlie 'Van Bitcoin' Shrem
May 27, 2012, 02:39:23 PM

1) cost - no smartphone I know of will be able to do a BTC transaction without costing over $100 or requiring a contract.  I assume bitcoincard will be under $50


It will be far under $50 Wink

Really??
That would be totally awesome. Can't imagine a better tool for blowing away my bitcoin-sceptical friends. I would immediately order a couple of units at a sub-10 btc (lets quote prices in real money!) price point.
Can't wait for june 10-15 to come round...

The workshop starts on the 11th!
legendary
Activity: 945
Merit: 1003
May 27, 2012, 12:15:17 PM

1) cost - no smartphone I know of will be able to do a BTC transaction without costing over $100 or requiring a contract.  I assume bitcoincard will be under $50


It will be far under $50 Wink

Really??
That would be totally awesome. Can't imagine a better tool for blowing away my bitcoin-sceptical friends. I would immediately order a couple of units at a sub-10 btc (lets quote prices in real money!) price point.
Can't wait for june 10-15 to come round...
legendary
Activity: 1008
Merit: 1021
Democracy is the original 51% attack
May 27, 2012, 11:44:54 AM

1) cost - no smartphone I know of will be able to do a BTC transaction without costing over $100 or requiring a contract.  I assume bitcoincard will be under $50


It will be far under $50 Wink
legendary
Activity: 1386
Merit: 1003
May 27, 2012, 11:25:30 AM
Quote
How are you going to do a Bitcoin tx when neither party has access to the internet?

Do some research on the matter.


No thanks.

Quote
Quote
No reason for a smartphone to have internet when you don't want it to.  "Airplane mode" disables all radios at the device level.  Kinda hard to be online when you have no signal. Wink

Unless you intend to carry a second phone to actually make calls, texts or use the Internet while mobile; you're going to turn that mode off eventually.  I'm not concerned about a live hacker taking my money, I'm concerned about a worm or virus that steals android wallets.  That only takes a few seconds.

So what is the difference between 1 phone + 1 phone being used as a dedicated bitcoin device  vs 1 phone + dedicated bitcoin device.

My point is the hardware already exists.  It is called a smartphone.  It has everything you need including connectivity and software.

For most casual users a single device is fine for the paranoid just carry two.  

The aim here is to provide (maybe a niche but I think not) a device that has better properties then a smartphone for bitcoin. 

1) cost - no smartphone I know of will be able to do a BTC transaction without costing over $100 or requiring a contract.  I assume bitcoincard will be under $50
2) size - no smartphone fits in the wallet
3) security - maybe through obscurity but most of the smartphones that COULD run a BTC transaction are running Android and would be more susceptible to a hack then the bitcoincard.  Malware may be on as much as 20% of all Android phones making it a bad place for the masses to store BTC.
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