Block size limit controversy

2015-12-01T13:41:17Z

Hameddk: Added Coinify statement

{{current}}{{see also|Scalability FAQ}}
[[Block]]s are limited to 1MB in size. Miners can mine blocks up to the 1MB fixed limit, but any block larger than 1MB is invalid. This limit cannot be modified without a hard fork. To prevent Bitcoin from temporarily or permanently splitting into separate payment networks ("altcoins"), hard forks require adoption by nearly all [[Full node#Economic_strength|economically active]] full nodes.

== Arguments in favor of increasing the blocksize ==
* More transactions per second
* Off-chain solutions are not yet ready to take off the load from the main blockchain.

== Contentions ==
* Increased blocksize will leave space for extensions like Mastercoin, Counterparty, etc.
** Neutral: Bitcoin competitors will have lower fees
** Negative: Bitcoin full nodes are forced to use more resources that don't support Bitcoin
* Small blocks eventually will require higher fees for fast confirmations.
** Positive: It will no longer be cheap to spam transactions such as Satoshi Dice bets
** Positive: Fees will not be zero. This is eventually a necessity in order to incentivize miners and secure the mining ecosystem
** Negative: Bitcoin may look unattractive to new users with high fees
** Negative: High fees may stop or reverse global adoption, investment, development, support and centralization{{clarification needed}}
** Negative: Bitcoin users pay higher fees
* A low blocksize limit encourages higher transactions fees to incentivize miners ("let a fee market develop").
** A fee market naturally develops due to miner latency regardless<ref>https://dl.dropboxusercontent.com/u/43331625/feemarket.pdf A Transaction Fee Market Exists Without a Block Size Limit</ref>
*** The relay network can be optimized so that miners don't have a stale rate increasing with latency. This should cause the fee market to once again require a block size limit to exist.

== Arguments in opposition to increasing the blocksize ==
* A hard fork requires waiting for sufficient consensus.
* Risk of catastrophic consensus failure<ref>https://www.mail-archive.com/bitcoin-development@lists.sourceforge.net/msg08276.html</ref>{{clarification needed}}
* An emergency hard fork that can achieve consensus can be deployed on a short time period if needed.<ref>[https://www.reddit.com/r/Bitcoin/comments/392m43/mike_hearn_blocksize_debate_at_the_breaking_point/cs00wdd How to raise block size in a short time], Peter Todd, Reddit /r/Bitcoin, 9 June 2015</ref>
* Orphan rate amplification, more reorgs and double-spends due to slower propagation speeds.
* European/American pools at more of a disadvantage compared to the Chinese pools{{why}}
* "Congestion" concerns can be solved with mempool improvements including transaction eviction.
* No amount of max block size would support all the world's future transactions on the main blockchain (various types of off-chain transactions are the only long-term solution)
* Fast block propagation is either not clearly viable, or (eg, IBLT) creates centralised controls.

=== Damage to decentralization ===
* Larger blocks make full nodes more expensive to operate.
* Therefore, larger blocks lead to less hashers running full nodes, which leads to centralized entities having more power, which makes Bitcoin require more trust, which weakens Bitcoins value proposition.
* Bitcoin is only useful if it is decentralized because centralization requires trust. Bitcoins value proposition is trustlessness.
* The larger the hash-rate a single miner controls, the more centralized Bitcoin becomes and the more trust using Bitcoin requires.
* Running your own full node while mining rather than giving another entity the right to your hash-power decreases the hash-rate of large miners. Those who have hash-power are able to control their own hash power if and only if they run a full node.
* Less individuals who control hash-power will run full nodes if running one becomes more expensive<ref>https://www.weusecoins.com/why-blocksize-limit-keeps-bitcoin-free-decentralized/</ref>.

==Proposals==
===BIP 100===
Change block size limit based on miner votes, but don't leave the range (1MB, 32MB) without a softfork or hardfork respectively.
===BIP 101===
{{seealso|Bitcoin XT}}
Increase to 8 MB after both January 11, 2016 has passed and 75% of miners are supporting. Double the limit every two years with the size increasing linearly within those two year intervals.
===BIP 102===
Increase to 2 MB on November 11, 2015.
===BIP 103===
Increase by 17.7% annually until 2063.

== Entities positions ==
Positions below are based on a suggested fixed block size increase to 20MiB. Positions against these larger blocks do not necessarily imply that they are against an increase in general, and may instead support a smaller and/or gradual increase.
{| class="wikitable sortable"
! Entity
! Supports Larger Blocks
! Supports Hard Fork
|-
| Bitcoinpaygate
| {{No|No: "We do NOT support the blocksize increase"}}<ref>http://www.reddit.com/r/Bitcoin/comments/37y8wm/list_of_bitcoin_services_that_supportoppose/crqsnqp</ref>
|
|-
| Bitrated
| {{No}} "At this time, I oppose increasing the block size limit as per Gavin's proposal" - Nadav Ivgi (founder)<ref>https://twitter.com/shesek/status/605005384026177537</ref>
|
|-
| [[GreenAddress]]
| {{No|No: "In our mind increasing the block size like this is just pushing the problem a little further at potentially unfixable costs."}}<ref>http://www.reddit.com/r/Bitcoin/comments/35anax/list_of_bitcoin_services_that_support_increasing/cr2mq84</ref>
|
|-
| [[MPEx]]
| {{No}}<ref>http://log.bitcoin-assets.com//?date=07-01-2015#967332</ref>
|
|-
| [[Paymium]]
| {{No|No: "<nowiki>[allow]</nowiki> a sane transaction fee market to emerge, by letting the blocks actually fill-up."}} - CTO David Francois<ref>http://fr.anco.is/2015/gavineries/</ref>
|
|-
| Ethereum 
| {{Neutral|Neutral: "If <nowiki>[the niche of digital gold]</nowiki> is what Bitcoin users want, then they should keep the limit, and perhaps even decrease it. But if Bitcoin users want to be a payment system, then up it must go."}} - Vitalik Buterin (founder)<ref>http://www.reddit.com/r/ethereum/comments/380q61/i_know_this_may_not_directly_be_ethereum_related/crrofl6</ref>
|
|-
| [[F2Pool]]
| {{Neutral|Neutral: "We do support bigger blocks and sooner rather than later. But we cannot handle 20 MB blocks right now. ... I think we can accept 5MB block at most."}}<ref>http://sourceforge.net/p/bitcoin/mailman/message/34157036/],[http://sourceforge.net/p/bitcoin/mailman/message/34158911/</ref>
|
|-
| [[Armory]]
| {{Yes}} "This *is* urgent and needs to be handled right now, and I believe Gavin
has the best approach to this." - CEO Alan Reiner<ref>http://sourceforge.net/p/bitcoin/mailman/message/34093337/</ref>
|
|-
| BitcoinReminder
| {{Yes|Yes: "BitcoinReminder.com also supports 20MB blocks (or even more?"}}<ref>http://www.reddit.com/r/Bitcoin/comments/37y8wm/list_of_bitcoin_services_that_supportoppose/crs9ytd</ref>
|
|-
| BitHours
| {{Yes|Yes: "We support @gavinandresen and his proposal for 20mb blocks"}}<ref>https://twitter.com/bithours/status/605131647747358721</ref>
|
|-
| [[BitPay]]
| {{Yes}} "Agreed (but optimistic this will be the last and only time block size needs to increase)" - CEO Stephen Pair<ref>https://twitter.com/spair/status/595341090317799424</ref>
| {{Yes|Yes: "In summary, we believe BIP 101 will safeguard Bitcoin’s decentralized nature while providing a reliable, immediate path toward greater network throughput, and we would like to express our support for merging BIP 101 into Bitcoin Core."}} - Stephen Pair<ref>https://medium.com/@spair/increasing-the-block-size-limit-85ff236fc516</ref>
|-
| Bittiraha.fi
| {{Yes|Yes: "We are supporting increasing #Bitcoin max block size to 20MB."}}<ref>https://twitter.com/Bittirahafi/status/596682373028311040</ref> "I'm strongly in favor of the block size cap increase to 20MB." - CEO Henry Brade<ref>https://twitter.com/Technom4ge/status/596334370803326978</ref>
| {{Yes}} "And I'm in favor of releasing a version with this change even with opposition." - CEO Henry Brade<ref>https://twitter.com/Technom4ge/status/596334370803326978</ref>
|-
| [[Blockchain.info]]
|{{Yes}} "It is time to increase the block size. Agree with @gavinandresen" - CEO Peter Smith<ref>https://twitter.com/OneMorePeter/status/595676380320407553</ref> "Scaling #bitcoin is a big deal. Increase the block size." - Nic Cary<ref>https://twitter.com/niccary/status/595707211994763264</ref>
|
|-
| [[Blocktrail]]
|{{Yes}} "We'd love to see BIP101 with 4mb start, alternatively BIP100 with something to deal with the 21% attack could be good too."<ref>https://blog.blocktrail.com/2015/08/miners-block-size-vote-explained/</ref> 
|
|-
| Breadwallet
| {{Yes}} "[...] in support of the Gavin's 20Mb block proposal." - CEO Aaron Voisine<ref>http://sourceforge.net/p/bitcoin/mailman/message/34096857/</ref>
|
|-
| [[BTC Guild]]

| {{Yes}} "Needs to happen, but needs future expansion built in at a reasonable rate." - Eleuthria<ref>https://www.reddit.com/r/Bitcoin/comments/370rko/21_inc_engineer_everyone_assumes_humans_will_be/crjfnpg?context=3</ref>
|
|-
| BX.in.th
| {{Yes|Yes: "<nowiki>http://BX.in.th</nowiki> will support the 20MB block size"}}<ref>https://twitter.com/BitcoinThai/status/605022509101023232</ref>
|
|-
| [[Coinbase (business)|CoinBase]]
| {{Yes|Yes: "Coinbase supports increasing the maximum block size"}}<ref>https://twitter.com/coinbase/status/595741967759335426</ref> "Why we should increase the block size" - CEO Brian Armstrong<ref>https://twitter.com/brian_armstrong/status/595453245884997634</ref>
| {{Yes|Yes: "5/ hard forks probably shouldn't happen frequently, but periodically they are an elegant solution that helps bitcoin keep growing"}} - CEO Brian Armstrong<ref>https://twitter.com/brian_armstrong/status/633309671994998784</ref>
|-
| [[Coinify]]
| {{Yes}} "We see Bitcoin XT as the best solution for ensuring the future scalability of the Bitcoin network." - CTO Hamed Sattari<ref>https://news.coinify.com/coinify-supports-bitcoin-xt-scalability-bitcoin-payments/</ref>
|
|-
| [[Dr. Adam Back (individual)|Dr. Adam Back]]
| {{Yes|Yes: "For the record I am not aware of a single person who has said they do not agree with scaling Bitcoin. Changing a constant is not the hard-part. The hard part is validating a plan and the other factors that go into it. It's not a free choice it is a security/scalability tradeoff. No one will thank us if we "scale" bitcoin but break it in hard to recover ways at the same time."}} <ref>https://www.mail-archive.com/bitcoin-development@lists.sourceforge.net/msg08276.html</ref>
| {{No}} "I strongly urge that we return to the existing collaborative constructive review process that has been used for the last 4 years which is a consensus by design to prevent one rogue person from inserting a backdoor, or lobbying for a favoured change on behalf of a special interest group, or working for bad actor" - Dr. Adam Back<ref>https://www.mail-archive.com/bitcoin-development@lists.sourceforge.net/msg08276.html</ref>
|
|-
| Kryptoradio
| {{Yes}} "#Kryptoradio dev @zouppen supports 20MB block size in #bitcoin." - Joel Lehtonen<ref>https://twitter.com/koodilehto/status/596675967667568641</ref>
|
|-
| [[OKCoin]]
| {{Yes|Yes: "OKCoin's tech team believes it's the right decision"}}<ref>https://twitter.com/okcoinbtc/status/598412795240009728</ref>
|
|-
| [[Third Key Solutions]]
| {{Yes}} "Gavin is right. The time to increase the block size limit is before transaction processing shows congestion problems." - CTO Andreas Antonopoulos<ref>https://twitter.com/aantonop/status/595601619581964289</ref>
|
|-
| [[Xapo]]
| {{Yes|Yes: "One meg is not enough: Xapo supports increasing the maximum block size"}} - CEO Wences Casares<ref>https://twitter.com/wences/status/595768917907402752</ref>
|
|}

==References==
<references/>
[[Category:2015 events]]

Bitcoin Wiki - User contributions [en]

Block size limit controversy