Welcome! Grab pizza. Mint a drink.

1Download Wally Wallet
2Mint a bong
3Melt it at the bar

Pizza · open bar · talk at 17:30

wallywallet.org

Nexa: Scaling Bitcoin

jQrgen · Oslo Blockchain Meetup · 2 October 2026

1

About me

NTNUinformatics + entrepreneurshipTrondheimOpen Blockchain MeetupBitcoin UnlimitedVotePeer on-chain votingNexaconsultantmaster's degree focused on blockchain
2

Tonight

1Bitcoin vs Nexa
2The tech
3The bong quest
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Bitcoin Unlimited · since late 2015

2015member-run · open source · scale Bitcoin on-chain
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BTC → BCH → NEXA

BTCBCHNEXA2017 splitsame engineersnew chainown genesis · 21 June 2022 · no airdrop
5

Same DNA

BitcoinNexa
Max supply21 million21 trillion
Halving~4 years~4 years (1,050,000 blocks)
Block time10 min2 min
Proof of workSHA-256dNexaPoW
Pre-mine / dev allocationnonenone
Tokens—native
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NEXA pays the miners. Tokens are built in.

NEXAmining rewards + feesBONGTOKENNFTgroup tokens, built into the protocol
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Scalable · Secure · Decentralised

ScalableSecureDecentralisedBitcoinNexa: the aim
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Software + Hardware

SoftwareGraphene · parallel validation · dynamic block size · Tailstorm
HardwareFPGAs · the Blitz card
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Send the recipe, not the cake

full blockGraphenerebuilt from own mempool83.6% smallermeasured on our own mainnet node over 24 h (1 Oct 2026): 67 blocks · 0 decode failures
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Race the blocks

thread 1thread 2Block A✓ valid first: winsBlock B (huge, slow)✕ stopped
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Room to grow, automatically

today: a few hundred bytes2 MB floor12 MB once Tailstorm activates1,000 MB ceilingnext max = 10 × the higher of the 90-day and 365-day median block sizerecalculated every block · log scale
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Confirm in seconds

summarysummarymany small subblocks, found in parallel, merge into a DAG2 min2 min later

Implemented · activates with Hard Fork 2 (date provisional) · Keller et al., AFT 2023 · Live demo ↗ (private test chain, simulated 1.2 s delay)

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Bitcoin hashes. Nexa signs.

BitcoinNexa (NexaPoW)header + nonceSHA-256SHA-256≤ target?header commitment + nonceSHA-256 × 2SHA-256Schnorr-SIGN (hash = private key)SHA-256≤ target?
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CPU → GPU → ASIC → checkpoint

CPUJune 2022open-sourceCPU minerGPUNov 2022$10k bounty:open-source GPU minerASIC~Jan 2025DragonBall A21:mining centralisesCheckpointthenno reorgs deeperthan 200 blocks
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Single-purpose chips → e-waste

SHA-256only this, forevere-wastedata centres
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NexaPoW 2: built for FPGAs

Rule 30: the teaching example

  • 256 × 256 cells
  • every cell: its own rule
  • new rules every epoch
  • 160 KB private memory per hash
  • ends in an elliptic-curve multiply
  • target: commodity FPGAs

In design, unreleased, not in the node yet

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The miner's chip = the node's chip

FPGAEfinix Ti375MiningNexaPoW 2 (planned)NodeBlitz: verifies signatures8 W M.2 card for nexadsame elliptic-curve circuits → miners and node operators want the same chip
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60,000 TPS on the dev network

20,00040,00060,000100,000+ goalTPS load-tested on the dev network (nodes in Italy and Canada, standard ISP links)One Blitz card: ~297,000 signature checks/s in the lab
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Questions?

?
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Build on Nexa

Telegramt.me/nexacoin
Websitenexa.org
Nexa AI skillsgitlab.com/jQrgen/nexaaiskills
build.nexa.org
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The bong quest

Createtoken groupMinta bongMeltdestroy it on-chainBarone drink

"Bong" = Norwegian for a drink ticket

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Live: create a round of bongs

Createtoken groupMinta bongMeltdestroy it on-chainBarone drinkLIVE

Wally Wallet · native group tokens, no smart contract

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Thank you! Now go melt a bong.

slides + manuscript
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→ / click / swipe · F fullscreen · S presenter view · manuscript
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