This document discusses bitcoin transactions. It explains that transactions move value on the bitcoin network by wrapping the transfer of funds within a transaction prior to broadcasting. The structure of transactions includes inputs, which point to unspent transaction outputs (UTXOs) being used as funds, and outputs, which create new UTXOs. Standard transaction types include pay-to-public-key-hash, pay-to-public-key, multi-signature, and pay-to-script-hash transactions. The document provides examples of these transaction types and resources for exploring transactions further.

1. Bitcoin Transactions
Deconstructed
Presented by: Jeff Flowers
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2. Transactions
How is value moved on the network
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3. Overview
• Transactions
• General Structure
• Standard Types
• Methods of Inquiry
• Detailed Examples
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4. Transactions
• Movement of value on the network
• These actions are wrapped within a transaction prior to broadcast
• Transactions are in plain text and readable by all
• Broadcasted to all Bitcoin nodes
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5. Structure
These are data structures, as such conform to well defined rules
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6. • Inputs are the source of funds being moved, pointers to the
transaction hash and sequence number of the UTXO containing
moved value
• The output of a transaction is the creation of an unspent transaction
output (UTXO)
• UTXO are denominated in Satoshis
• A locking script that encumbers this value requiring specific
conditions to be met for the owner to spend
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7. Transaction Structure Cond.
• A transaction completely depletes the UTXO
being used
• Should only a portion be required, change
must be considered
• Change is the unused portion of the UTXO
being moved
• The difference between the new UTXO and
change is taken by the network as a fee
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8. Standard Transactions
• Pay-to-Public-Key-Hash (P2PKH)
• Pay-to-Public-Key
• Multi-Signature
• Data Output
• Pay-to-Script-Hash (P2SH)
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9. Standard Transactions
• Pay-to-Public-Key-Hash (P2PKH)
• Pay-to-Public-Key
• Multi-Signature
• Data Output
• Pay-to-Script-Hash (P2SH)
The majority of Bitcoin transactions today
are of this general type. These types of
transactions are used to transfer value,
typically from one user to another. They
are constructed having the form: scriptSig
(or the unlocking script) first, followed by
the scriptPubKey (or locking script).
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10. Standard Transactions
• Pay-to-Public-Key-Hash (P2PKH)
• Pay-to-Public-Key
• Multi-Signature
• Data Output
• Pay-to-Script-Hash (P2SH)
Another payment transaction. These types
of transactions are effectively outdated
with P2PKH being preferred. The public
key itself, not its hash, is stored in the
locking script. This has the advantages of
being shorter, though less secure.
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11. Standard Transactions
• Pay-to-Public-Key-Hash (P2PKH)
• Pay-to-Public-Key
• Multi-Signature
• Data Output
• Pay-to-Script-Hash (P2SH)
A M of N schema, where there are N total
number of keys and M are needed to
create the signature for a valid transaction.
Presently limited to a maximum of 15 listed
public keys.
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12. Standard Transactions
• Pay-to-Public-Key-Hash (P2PKH)
• Pay-to-Public-Key
• Multi-Signature
• Data Output
• Pay-to-Script-Hash (P2SH)
The allure of the Block Chain, as a single
source of shared truth embodied by a
immutable database opens up many
possibilities. Notary services and beyond.
As such, developers have wanted to take
full advantage of this instrument.
OP_RETURN allows for 40 bytes of data
to be stored in the block chain.
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13. Standard Transactions
• Pay-to-Public-Key-Hash (P2PKH)
• Pay-to-Public-Key
• Multi-Signature
• Data Output
• Pay-to-Script-Hash (P2SH)
Payment to P2SH goes instead to a
potentially complex locking script but rather
to the hash of the script. This greatly
shortens the overall size of the transaction.
A future spend of this UTXO requires the
script whose hash matches.
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14. My Method of Inquiry
After building my transaction, I had a serial hex mess -
But what did all of this stuff mean?
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17. Resources
• Builder (Bitcore): http://bit.ly/1ORgoeF
• Explorer: https://chain.so/
• Hex Converter: http://www.rapidtables.com/convert/number/hex-to-
ascii.htm
• Decoder: https://blockchain.info/decode-tx
• Broadcaster: https://live.blockcypher.com/bcy/pushtx/
• Blog: http://www.siliconian.com/blog
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