and resources while creating a peer to peer network within the Round Rock community.” Purpose: Grow bitcoin adoption by individuals and small businesses within our local community. Participation encouraged: Stay on topic (bitcoin only) Respect others’ privacy (Chatham house rules) Opportunities: - Free propaganda from bitcoin artists - Bitcoin Book Exchange - Hash The Torch 24 – Altairtech Urlacher Conversion Kit - Blockstream Local - Liquid Workshop Volunteers Ongoing call for speakers & sponsors - Next month: UncleJim21 to discuss CASCDR
to simulate privacy. • Each node starts by “downloading Bitcoin Core”. I.e. Receive basket of items. This is our physical representation of the Bitcoin core software, made up of many subcomponents.
'transaction commitment' is a Merkle root of all the block's transaction's ids. We don't have a quick and easy way to build a Merkle root. Instead we just use some basic math. eagle33
all information is entered. Write it above “blockheader” and on back of genesis txn. 000000 33 12:34 8500 103554 prev. block hash tx. commitment time target nonce ON/ CLEAR NEXT PREV.
facilitators (green pubkey, or “lock”) 1 BTC • Refer to your private key for your node’s color • Write any transaction fee on back of transaction card *This is real life and we’re playing with some level of trust; please LARP with only the color of your private key.
a blank nonce. • After the nonce is found, write down the block hash next to blockheader • RAISE YOUR HAND as soon as you find the nonce! 13. Mining For Nonces
notify all peers with “I HAVE BLOCKS” message w/ block hash(es). 14. Broadcasting & Requesting a Valid Block • Messages must be acted upon ASAP. Other nodes will send “SEND BLOCKS” message w/ hashes for blocks they need.
(EXCEPT block hash). ◦ Fill block ▪ Coinbase txn: Make copies to send ▪ Other txns: Use Compact Block Protocol (“block txids”) to copy all other txids to • Send valid blocks to nodes who requested it. 15. Sending Peers Valid Blocks • cat72 • dog83 • balloon18 7657 8500 prev. block hash tx. commitment time nonce target
is ≤50 + sum of txn fees • Only need to validate txns that are not already in mempool • If you don’t have listed transaction, you’ll need to request it from the node that sent block. • If you’re unable to find txn or if it’s already in UTXO set, it’s invalid. Discard block. • Txns can only spend from UTXOs or from other txns in same block; otherwise, block is invalid. 17. Validating Block Txns
• Cross-out any spent inputs in this block, and cross-out corresponding output • Any new outputs created in block get sent to UTXO set. • Add block to blockchain. 18. Marking Outputs as Spent
header ◦ Use new valid block’s hash for “previous block hash” ◦ Update time ◦ Pull out txns that were mined in pervious block ◦ Update coinbase txn, recalculate txn commitment ◦ Attempt to mine updated block 19. Building a chain