Quote from: prodigy on June 20, 2011, 07:09:49 PM

The transaction ledger grows each day, and because it's permanent, eventually it will get very computationally expensive to move a single coin because it has a huge transaction history built up on it.

Am I missing something here? To me it seems that over time the global block chain will grow in size to the point where it consumes all computing resources thrown at it. Home PC's can't be expected to store multi-gigabyte (or terabyte) block chains just to perform transactions.

As far as I understand this, the complete block chain is only needed to be downloaded once if you start a BitCoin client. If you want to make a transaction, you only put this transaction request (size depends only on the contents of your transaction) in the system. The next block that is computed for the block chain will (hopefully) include your transaction. This is the first affirmation of your transaction. If six further blocks are created without any problems regarding your transaction, it is believed as valid.
To compute a new block, only the last created block is needed. The hash of the last block goes into the new one - confirming the last one.
The hole block chain is only needed to verify that the hole block chain is valid.

Right now, each new block is about 10 MB in size. That is every ten minutes.
Right now I have nearly 500 MB data for 132129 blocks - thats nearly 4 KB each. When there where no transactions, the blocks had a size of 216 Bytes.
So maybe you are right, if there are more transactions, the block size will increase. Resulting in maybe a few hundred MB per block in a few months if BitCoins grow further and is maybe accepted by Amazon Cheesy

With an average of 144 blocks a day that would be more than 50 GB a day if the block size reaches 350 MB.
Hm, so maybe I should start to look for a faster internet connection.

That's what I understand this far.
Corrections welcome Wink