Bitcoin Forum

Bitcoin => Bitcoin Discussion => Topic started by: koistinen on June 06, 2011, 09:33:24 PM



Title: Fragmentation problem?
Post by: koistinen on June 06, 2011, 09:33:24 PM
Is fragmentation of bitcoins a problem and a possible attack on the system?
In http://forum.bitcoin.org/index.php?topic=9685.0 (http://forum.bitcoin.org/index.php?topic=9685.0) there is a question that did not get answered, and it is not in https://en.bitcoin.it/wiki/Weaknesses (https://en.bitcoin.it/wiki/Weaknesses).

The basic idea is that money can get fragmented and if you only have pennies to pay with, transaction costs go up.
If with bitcoins you can spend 10^-8 of a bitcoin, then the pennies might come to have very low value.
An attack might then be performed like this:
Buy 1.01 bc. Spend 1 bc on socks, but use the 0.01 bc to fragment the money sent into anything up to a million equal parts, say only enough to make it more expensive to use.
Whenever that 1 bc is spent, it is more expensive than an unfragmented bc would be.
This might also happen naturally over time when transactions with many decimals are made.

Whether or not this is a problem, perhaps it belongs in the Weaknesses article?


Title: Re: Fragmentation problem?
Post by: Quantumplation on June 06, 2011, 09:36:03 PM
Is fragmentation of bitcoins a problem and a possible attack on the system?
In http://forum.bitcoin.org/index.php?topic=9685.0 (http://forum.bitcoin.org/index.php?topic=9685.0) there is a question that did not get answered, and it is not in https://en.bitcoin.it/wiki/Weaknesses (https://en.bitcoin.it/wiki/Weaknesses).

The basic idea is that money can get fragmented and if you only have pennies to pay with, transaction costs go up.
If with bitcoins you can spend 10^-8 of a bitcoin, then the pennies might come to have very low value.
An attack might then be performed like this:
Buy 1.01 bc. Spend 1 bc on socks, but use the 0.01 bc to fragment the money sent into anything up to a million equal parts, say only enough to make it more expensive to use.
Whenever that 1 bc is spent, it is more expensive than an unfragmented bc would be.
This might also happen naturally over time when transactions with many decimals are made.

Whether or not this is a problem, perhaps it belongs in the Weaknesses article?


Coins can ALSO be merged in a transaction.  A transaction can take many inputs (100x 0.01 transactions, etc.) and have a single output (1 btc).


Title: Re: Fragmentation problem?
Post by: koistinen on June 06, 2011, 09:55:52 PM
Thanks, I think I misunderstood how coins are represented. That is, the data structure.