rich1.0npub1kc0zulxt7j4a0ayhzhrz7jk84y7tm4026qcky7w97hlfkxxap24qnwjfw4https://nostr.ae/npub1kc0zulxt7j4a0ayhzhrz7jk84y7tm4026qcky7w97hlfkxxap24qnwjfw4njumphttps://nostr.ae📅 Original date posted:2015-09-03 📝 Original message:Some comments: * The 75% rule is meaningless here. Since this is a pure relaxation of rules, there is no such thing as "invalid version 4 blocks" * The implication threshold is unclear. Is it 95% or 80%? * Softfork requires a very high threshold (95%) to "attack" the original fork. This makes sure that unupgraded client will only see the new fork. * In the case of hardfork, however, the new fork is unable to attack the original fork, and unupgraded client will never see the new fork. The initiation of a hardfork should be based on its acceptance by the economic majority, not miner support. 95% is an overkill and may probably never accomplished. I strongly prefer a 80% threshold rather than 95%. * As I've pointed out, using 20-percentile rather than median creates an incentive to 51% attack the uncooperative minority. https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010690.html Having said that, I don't have a strong feeling about the use of 20-percentile as threshold to increase the block size. That means the block size is increased only when most miners agree, which sounds ok to me. However, using 20-percentile as threshold to DECREASE the block size could be very dangerous. Consider that the block size has been stable at 8MB for a few years. Everyone are happy with that. An attacker would just need to acquire 21% of mining power to break the status quo and send us all the way to 1MB. The only way to stop such attempt is to 51% attack the attacker. That'd be really ugly. For technical and ethical reasons, I believe the thresholds for increase and decrease must be symmetrical: increase the block size when the x-percentile is bigger than the current size, decrease the block size when the (100-x)-percentile is smaller than the current size. The overall effect is: the block size remains unchanged unless 80% of miners agree to. * Please consider the use of "hardfork bit" to signify the hardfork: https://www.reddit.com/r/bitcoin_devlist/comments/3ekhg2/bip_draft_hardfork_bit_jl2012_at_xbthk_jul_23_2015/ https://github.com/jl2012/bips/blob/master/hardforkbit.mediawiki * Or, alternatively, please combine the hardfork with a softfork. I'm rewriting the specification as follow (changes underlined): * Replace static 1M block size hard limit with a floating limit ("hardLimit"). * hardLimit floats within the range 1-32M, inclusive. * Initial value of hardLimit is 1M, preserving current system. * Changing hardLimit is accomplished by encoding a proposed value within a block's coinbase scriptSig. * Votes refer to a byte value, encoded within the pattern "/BVd+/" Example: /BV8000000/ votes for 8,000,000 byte hardLimit. If there is more than one match with with pattern, the first match is counted. * Absent/invalid votes and votes below minimum cap (1M) are counted as 1M votes. Votes above the maximum cap (32M) are counted as 32M votes. * A new hardLimit is calculated at each difficult adjustment period (2016 blocks), and applies to the next 2016 blocks. * Calculate hardLimit by examining the coinbase scriptSig votes of the previous 12,000 blocks, and taking the 20th percentile and 80th percentile. * New hardLimit is the median of the followings: * min(current hardLimit * 1.2, 20-percentile) * max(current hardLimit / 1.2, 80-percentile) * current hardLimit * version 4 block: the coinbase of a version 4 block must match this pattern: "/BVd+/" * 70% rule: If 8,400 of the last 12,000 blocks are version 4 or greater, reject invalid version 4 blocks. (testnet4: 501 of last 1000) * 80% rule ("Point of no return"): If 9,600 of the last 12,000 blocks are version 4 or greater, reject all version <= 3 blocks. (testnet4: 750 of last 1000) * Block version number is calculated after masking out high 16 bits (final bit count TBD by versionBits outcome). Jeff Garzik via bitcoin-dev 於 2015-09-02 23:33 寫到: > BIP 100 initial public draft: > https://github.com/jgarzik/bip100/blob/master/bip-0100.mediawiki [1] > > Emphasis on "initial" This is a starting point for the usual open > source feedback/iteration cycle, not an endpoint that Must Be This > Way. > > > > Links: > ------ > [1] https://github.com/jgarzik/bip100/blob/master/bip-0100.mediawiki > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev at lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20150903/9bfb6c46/attachment.html>