Bitcoin Network & Bitcoin Core by Bitcoin (open-source protocol; Bitcoin Core maintainers): status and timeline

Milestones

Next · BIP-360 adoption and migration to quantum-resistant addresses

Bitcoin network launchesJan 2009Complete.
First halving (reward 50 → 25 BTC)Nov 2012Complete.
SegWit soft fork activatesAug 2017Complete.
Taproot soft fork activatesNov 2021Complete.
Bitcoin Core v30 released with OP_RETURN increaseOct 2025Complete.
BIP-360 quantum-resistant address proposal mergedFeb 2026Complete.

Most important updates

Bitcoin Core merges BIP-360, introducing quantum-resistant P2MR addresses11 Feb 2026
Bitcoin hashrate tops 1 Zettahash/second as mining expandsJan 2026
Bitcoin Core v30.0 released with OP_RETURN limit raised from 80 bytes to 100 KB12 Oct 2025

Upcoming

2027BIP-360 adoption and migration to quantum-resistant addresses (next)
2035Large-scale quantum computer development

Current obstacles

Quantum computing threatECDSA can be broken by a quantum computer using Shor's algorithm. BIP-360 adds quantum-resistant addresses, but migration is voluntary.
Community disagreement on protocol scopeThe OP_RETURN limit increase split developers. Some want Bitcoin as currency only; others want arbitrary data. No formal mechanism resolves disagreement.

Physics limits

Block size throughput ceiling1 MB base block + 4 MW witness = ~4 MB weight limit. This caps throughput at ~7 transactions/second on-chain. Off-chain solutions (Lightning) aim to scale.
Proof-of-work energy costSecuring the network with computation requires ~100-150 TWh/year electricity. This makes Bitcoin expensive to attack but unpopular in some regions.
Hard-fork governance riskChanges that make old blocks invalid require a hard fork. If 10% of the network doesn't upgrade, two cryptocurrencies exist. This makes fundamental changes nearly impossible.

How it works

3 parts

Mining

SHA-256 proof-of-work

Miners search for a SHA-256 hash below target difficulty. Difficulty adjusts every 2 weeks to keep block time at 10 minutes.

Consensus

Longest cumulative-work chain rule

Nodes accept the chain with the most total work. This makes it computationally infeasible to rewrite history; an attacker needs >50% hashrate.

Decentralization

No central authority enforces upgrades

A proposed change activates only if nodes choose to run new code. This gives stakeholders veto power but makes consensus changes slow.

Spec sheet

Spec	Bitcoin Network & Bitcoin Core
Total BTC supply (maximum)	21 million^R (reported)
Network hashrate (January 2026)	>1 Zettahash/s^R (reported)
Average block time	~10 minutes^R (reported)
OP_RETURN limit (Core v30)	100 KB^R (reported)
Estimated full nodes globally	~40,000^E (estimated)

^R reported by the company · ^E our estimate

Update log

3 updates

About Bitcoin (open-source protocol; Bitcoin Core maintainers)

The team behind Bitcoin Network & Bitcoin Core

Bitcoin (open-source protocol; Bitcoin Core maintainers)

Blockchain, cryptocurrency, peer-to-peer

Bitcoin is a decentralized digital currency and blockchain created in 2009. Bitcoin Core, the reference implementation, is maintained by volunteer developers with no central authority. Protocol changes require community consensus.

Bitcoin Core v30.0 (October 2025) raised OP_RETURN limit to 100 KB, dividing the community on data storage.
February 2026: Bitcoin Core merged BIP-360, introducing quantum-resistant P2MR addresses.
Network hashrate hit 1+ Zettahash/second in January 2026. Winter storm in February curtailed Texas mining.

bitcoincore.org (opens bitcoincore.org)Company profile →

Founded: 200917 yrs
Headquarters: United States
Status: Public
Valuation: public
Works in: CryptoBlockchains (L1s)
Coverage: 1 program · 3 updateslatest 11 Feb 2026checked 10 Oct
Partners: Brink (opens brink.dev)OpenSats (opens opensats.org)Human Rights Foundation (opens hrf.org)
People: Gloria Zhao (opens github.com)Bitcoin Core maintainer, mempool/policyRyan Ofsky (opens github.com)Bitcoin Core maintainerHennadii Stepanov (opens github.com)Bitcoin Core maintainerAva Chow (opens github.com)Bitcoin Core maintainer

Spec

Bitcoin Network & Bitcoin Core

Total BTC supply (maximum)

21 million^R (reported)

Network hashrate (January 2026)

>1 Zettahash/s^R (reported)

Average block time

~10 minutes^R (reported)

OP_RETURN limit (Core v30)

100 KB^R (reported)

Estimated full nodes globally

~40,000^E (estimated)

Bitcoin Network & Bitcoin Core

Milestones

Most important updates

Upcoming

Current obstacles

Physics limits

How it works

SHA-256 proof-of-work

Longest cumulative-work chain rule

No central authority enforces upgrades

Spec sheet

Update log

Wed 11 Feb

Jan 2026

Sun 12 Oct 2025

About Bitcoin (open-source protocol; Bitcoin Core maintainers)

Current obstacles

Physics limits

How it works

SHA-256 proof-of-work

Longest cumulative-work chain rule

No central authority enforces upgrades

Spec sheet

Update log

Wed 11 Feb

Jan 2026

Sun 12 Oct 2025

About Bitcoin (open-source protocol; Bitcoin Core maintainers)