Plan
Terms
What is transaction
What is included there
Change and fee
Creation of the transaction
How can you spend the result
Terms
tx – transaction
txid – id of a transaction. Is used to search a transaction in blockchain
Script – the name of the script language that describes how a client should validate transactions
UTXO - Unspent Transaction Output – transactions output
Wallet – key pair
Address – public key
Transaction format
Transaction – a signed piece of data that authorizes the sending of funds from one account to another
Service information – identifies the transaction and allows implementing it correctly
Input – information about where the sender got money from and proof that sender owns this money
Output – information about where money is flowing to
identifier of transaction amount of inputs and
outputs hash of transaction
that is spent here
signature of the sender and their public key
amount of money that is transferred
address where money goes
Most important fields
Input
Account has no “balance” There is a list of not spent transactions (cheques) Input indicates which previous transaction
should be spent Input contains also a signature of the sender
Change and fee
All the money from previous transaction (you can find this amount if you look up previous transaction) is spent in the current one
Difference between money that input has and output spends is considered a fee and is taken by miners
If you don’t want to pay high fee :) you have to create output that returns change for you (thats why transactions with many outputs are needed)
Change money is sent to address that you control
Combining your unspent transactions
If none of the unspent transactions that you have (UTXO) contains enough money to pay - you have to combine a few
Here transactions with a few inputs are needed Money are summed up (and fee paid to miners is
calculated in the same way - difference between total input and total output)
Your wallet (a piece of software) contains key pairs - that is money that you control
Summary
Every balance which is received or sent should be tied to the address
Every address may be associated with the wallet. All the rest – non-spendable, the coins that are sent to them – are lost
The balance that can be spent was always received from the wallet
The coins received to the address are not mixed – they are used separately (or in a combination) in the moment when they are spent
If the sum of all inputs is more, than the sum of outputs, the change is considered to be a commission