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📅 Original date posted:2017-08-16 📝 Original message:What ...

2023-06-07T20:04:48+02:00

In reply to nevent1q…6x4a
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📅 Original date posted:2017-08-16
📝 Original message:What makes this approach better than the prune option of Bitcoin?

On Wed, Aug 16, 2017 at 10:20 AM, Алексей Мутовкин via bitcoin-dev <
bitcoin-dev at lists.linuxfoundation.org> wrote:

>
> Let me describe the possible improvement of the bitcoin blockchain
> database (BBD) size in general terms.
>
> We can implement new routine : annual split of the BBD. Reason is that
> 140gb full wallet unconvinience.
>
> BBD splits in two parts :
> 1) old blocks before the date of split and
> 2) new blocks, starting from first technical block with all rolled totals
> on the date of split.
> (also possible transfer of tiny totals due to their unprofitability to
> the miners, so we cut long tail of tiny holders)
> 3) old blocks packs into annual megablocks and stores in the side archive
> chain for some needs for FBI investigations or other goals.
>
>
> Thanks for your attention,
>
> Alexey Mutovkin
>
>
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev at lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>
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📅 Original date posted:2017-03-20 📝 Original message:Chain ...

2023-06-07T19:57:25+02:00

In reply to nevent1q…q5xr
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📅 Original date posted:2017-03-20
📝 Original message:Chain work currently means the expected number of sha256d evaluations
needed to build a chain. Given that these hash functions are not equally
hard, what should the new definition of chain work be?

On Mon, Mar 20, 2017 at 9:38 AM, Andrew Johnson via bitcoin-dev <
bitcoin-dev at lists.linuxfoundation.org> wrote:

> By doing this you're significantly changing the economic incentives behind
> bitcoin mining. How can you reliably invest in hardware if you have no idea
> when or if your profitability is going to be cut by 50-75% based on a whim?
>
> You may also inadvertently create an entirely new attack vector if 50-75%
> of the SHA256 hardware is taken offline and purchased by an entity who
> intends to do harm to the network.
>
> Bitcoin only works if most miners are honest, this has been known since
> the beginning.
>
> On Mon, Mar 20, 2017 at 9:50 AM John Hardy via bitcoin-dev <
> bitcoin-dev at lists.linuxfoundation.org> wrote:
>
>> I’m very worried about the state of miner centralisation in Bitcoin.
>>
>> I always felt the centralising effects of ASIC manufacturing would
>> resolve themselves once the first mover advantage had been exhausted and
>> the industry had the opportunity to mature.
>>
>> I had always assumed initial centralisation would be harmless since
>> miners have no incentive to harm the network. This does not consider the
>> risk of a single entity with sufficient power and either poor, malicious or
>> coerced decision making. I now believe that such centralisation poses a
>> huge risk to the security of Bitcoin and preemptive action needs to be
>> taken to protect the network from malicious actions by any party able to
>> exert influence over a substantial portion of SHA256 hardware.
>>
>> Inspired by UASF, I believe we should implement a Malicious miner
>> Reactive Proof of Work Additions (MR POWA).
>>
>> This would be a hard fork activated in response to a malicious attempt by
>> a hashpower majority to introduce a contentious hard fork.
>>
>> The activation would occur once a fork was detected violating protocol
>> (likely oversize blocks) with a majority of hashpower. The threshold and
>> duration for activation would need to be carefully considered.
>>
>> I don’t think we should eliminate SHA256 as a hashing method and change
>> POW entirely. That would be throwing the baby out with the bathwater and
>> hurt the non-malicious miners who have invested in hardware, making it
>> harder to gain their support.
>>
>> Instead I believe we should introduce multiple new proofs of work that
>> are already established and proven within existing altcoin implementations.
>> As an example we could add Scrypt, Ethash and Equihash. Much of the code
>> and mining infrastructure already exists. Diversification of hardware (a
>> mix of CPU and memory intensive methods) would also be positive for
>> decentralisation. Initial difficulty could simply be an estimated portion
>> of existing infrastructure.
>>
>> This example would mean 4 proofs of work with 40 minute block target
>> difficulty for each. There could also be a rule that two different proofs
>> of work must find a block before a method can start hashing again. This
>> means there would only be 50% of hardware hashing at a time, and a sudden
>> gain or drop in hashpower from a particular method does not dramatically
>> impact the functioning of the network between difficulty adjustments. This
>> also adds protection from attacks by the malicious SHA256 hashpower which
>> could even be required to wait until all other methods have found a block
>> before being allowed to hash again.
>>
>> 50% hashing time would mean that the cost of electricity in relation to
>> hardware would fall by 50%, reducing some of the centralising impact of
>> subsidised or inexpensive electricity in some regions over others.
>>
>> Such a hard fork could also, counter-intuitively, introduce a block size
>> increase since while we’re hard forking it makes sense to minimise the
>> number of future hard forks where possible. It could also activate SegWit
>> if it hasn’t already.
>>
>> The beauty of this method is that it creates a huge risk to any malicious
>> actor trying to abuse their position. Ideally, MR POWA would just serve as
>> a deterrent and never activate.
>>
>> If consensus were to form around a hard fork in the future nodes would be
>> able to upgrade and MR POWA, while automatically activating on non-upgraded
>> nodes, would be of no economic significance: a vestigial chain immediately
>> abandoned with no miner incentive.
>>
>> I think this would be a great way to help prevent malicious use of
>> hashpower to harm the network. This is the beauty of Bitcoin: for any road
>> block that emerges the economic majority can always find a way around.
>>
>> _______________________________________________
>> bitcoin-dev mailing list
>> bitcoin-dev at lists.linuxfoundation.org
>> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>>
> --
> Andrew Johnson
>
>
> _______________________________________________
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> bitcoin-dev at lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>
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📅 Original date posted:2017-03-13 📝 Original ...

2023-06-07T19:57:14+02:00

In reply to nevent1q…9srl
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📅 Original date posted:2017-03-13
📝 Original message:>time >= 1506816000 && time <= 1510704000 && !IsWitnessEnabled()
This has a different start time from the first post.
>if (pindex->GetMedianTimePast() >= 1538352000 &&
pindex->GetMedianTimePast() <= 1510704000 ...

Thanks,
--Nick

On Mon, Mar 13, 2017 at 4:36 AM, shaolinfry via bitcoin-dev <
bitcoin-dev at lists.linuxfoundation.org> wrote:

> From: luke at dashjr.org
> On Sunday, March 12, 2017 3:50:27 PM shaolinfry via bitcoin-dev wrote:
> > // mandatory segwit activation between Oct 1st 2017 and Nov 15th 2017
> > inclusive if (pindex->GetMedianTimePast() >= 1538352000 &&
> > pindex->GetMedianTimePast() <= 1510704000 &&
> > !IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus())) {
> > if (!((pindex->nVersion & VERSIONBITS_TOP_MASK) ==
> > VERSIONBITS_TOP_BITS) && (pindex->nVersion & VersionBitsMask(params,
> > Consensus::DEPLOYMENT_SEGWIT)) != 0) {
> > return state.DoS(2, error("ConnectBlock(): relayed block must
> > signal for segwit, please upgrade"), REJECT_INVALID,
> > "bad-no-segwit");
> > }
> > }
>
> I don't think this is actually BIP 9 compatible. Once activated, the bit
> loses
> its meaning and should not be set. So you need to check that it hasn't
> locked-
> in already...
>
>
> I believe that is handled.
>
> time >= 1506816000 && time <= 1510704000 && !IsWitnessEnabled()
>
> Signalling is only required from October 1st until the BIP9 timeout, or,
> until segwit is activated. The bit becomes free after activation/timeout as
> per BIP9. Also, the default behaviour of BIP9 in Bitcoin Core is to signal
> through the LOCKED_IN period - it would be trivial to add a condition to
> not require mandatory signalling during LOCKED_IN but since miners signal
> by default during this period, I figured I would leave it.
>
> I thought about 5% tolerance. but I don't think it makes sense since
> miners will already have plenty of warning this is coming up and the intent
> of the mandatory signalling period is quite clear. It also seems a bit
> weird to say "it's mandatory but not for 5%". If miners are required to
> signal, they need to signal. It also adds unnecessary complexity to an
> otherwise simple patch.
>
> That said, I have no strong feelings either way on both counts, but I
> chose to present the simplest option first.
>
> _______________________________________________
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> bitcoin-dev at lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
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>
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📅 Original date posted:2015-11-06 📝 Original message:Your ...

2023-06-07T19:44:17+02:00

In reply to nevent1q…kmw0
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📅 Original date posted:2015-11-06
📝 Original message:Your suggested modification seems sound.

Though, a script author could do something similar right now by
prefacing his IF with this:

OP_DUP OP_DUP OP_0 OP_EQUAL OP_SWAP OP_1 OP_EQUAL OP_BOOLOR
OP_NOTIF OP_RETURN OP_ENDIF [actual OP_IF goes here]

That checks whether the input is 0 or 1, and runs OP_RETURN if not.
Your way is cleaner, though.

On Fri, Nov 6, 2015 at 1:13 AM, jl2012 via bitcoin-dev
<bitcoin-dev at lists.linuxfoundation.org> wrote:
> I have a new BIP draft for fixing OP_IF and OP_NOTIF malleability. Please
> comment:
> https://github.com/jl2012/bips/blob/master/opifmalleability.mediawiki
>
> Copied below:
>
> BIP: x
> Title: Dealing with OP_IF and OP_NOTIF malleability
> Author: jl2012 <jl2012 at xbt.hk>
> Status: Draft
> Type: Standards Track
> Created: 2015-11-06
>
> Abstract
>
> As an supplement to BIP62, this document specifies proposed changes to the
> Bitcoin transaction validity rules in order to make malleability of
> transactions with OP_IF and OP_NOTIF impossible.
>
> Motivation
>
> OP_IF and OP_NOTIF are flow control codes in the Bitcoin script system. The
> programme flow is decided by whether the top stake value is 0 or not.
> However, this behavior opens a source of malleability as a third party may
> alter a non-zero flow control value to any other non-zero value without
> invalidating the transaction.
>
> As of November 2015, OP_IF and OP_NOTIF are not commonly used in the
> blockchain. However, as more sophisticated functions such as
> OP_CHECKLOCKTIMEVERITY are being introduced, OP_IF and OP_NOTIF will become
> more popular and the related malleability should be fixed. This proposal
> serves as a supplement to BIP62 and should be implemented with other
> malleability fixes together.
>
> Specification
>
> If the transaction version is 3 or above, the flow control value for OP_IF
> and OP_NOTIF must be either 0 or 1, or the transaction fails.
>
> This is to be implemented with BIP62.
>
> Compatibility
>
> This is a softfork. To ensure OP_IF and OP_NOTIF transactions created before
> the introduction of this BIP will still be accpeted by the network, the new
> rules only apply to transactions of version 3 or above.
>
> For people who want to preserve the original behaviour of OP_IF and
> OP_NOTIF, an OP_0NOTEQUAL could be used before the flow control code to
> transform any non-zero value to 1.
>
> Reference
>
> BIP62: https://github.com/bitcoin/bips/blob/master/bip-0062.mediawiki
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev at lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev