Mastering Bitcoin by Andreas M. Antonopoulos

Author:Andreas M. Antonopoulos [Antonopoulos, Andreas M.]
Language: eng
Format: epub, mobi, pdf
Tags: Bitcoin, O'Reilly
ISBN: 9781491902615
Publisher: O’Reilly Media
Published: 2014-04-08T18:30:00+00:00

Figure 2-9. Alice’s transaction included in block #277,317

Spending the transaction

Now that Alice’s transaction has been embedded in the blockchain as part of a block, it is part of the distributed ledger of bitcoin and visible to all bitcoin applications. Each bitcoin client can independently verify the transaction as valid and spendable. Full-index clients can track the source of the funds from the moment the bitcoins were first generated in a block, incrementally from transaction to transaction, until they reach Bob’s address. Lightweight clients can do a Simple Payment Verification (See SPV:(to come)) by confirming that the transaction is in the blockchain and has several blocks mined after it, thus providing assurance that the network accepts it as valid.

Bob can now spend the output from this and other transactions, by creating his own transactions that reference these outputs as their inputs and assign them new ownership. For example, Bob can pay a contractor or supplier by transferring value from Alice’s coffee cup payment to these new owners. Most likely, Bob’s bitcoin software will aggregate many small payments into a larger payment, perhaps concentrating all the day’s bitcoin revenue into a single transaction. This would move the various payments into a single address, utilized as the store’s general “checking” account. For a diagram of an aggregating transaction, see Figure 2-6.

As Bob spends the payments received from Alice and other customers, he exends the chain of transactions, which in turn are added to the global blochcain ledger for all to see and trust. Let’s assume that Bob pays his web designer Gopesh in Bangalore for a new web site page. Now the chain of transactions will look like this:

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.