From 19caed45a190aee8a0e7792d8e819d6de6ee5ae6 Mon Sep 17 00:00:00 2001 From: Antoine Poinsot Date: Wed, 20 May 2026 16:41:18 -0400 Subject: [PATCH] bip-0054: rephrase Timewarp motivation --- bip-0054.md | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/bip-0054.md b/bip-0054.md index 7eb277f0..efdc0866 100644 --- a/bip-0054.md +++ b/bip-0054.md @@ -21,16 +21,14 @@ case block validation time, prevent Merkle tree weaknesses, and avoid duplicate This proposal addresses a number of long-standing vulnerabilities and weaknesses in the Bitcoin protocol. Bundling these fixes together amortizes the fixed cost of deploying a Bitcoin soft fork. -The timewarp bug permits a majority hashrate attacker to arbitrarily increase the block rate, -allowing them to steal block subsidy from future miners and increase validation costs to nodes that -have to deal with the increased average transaction rate. By strategically setting the block -timestamp, the [timewarp bug][SE timewarp] lets miners bring down the difficulty to its minimum -within 38 days of starting the attack. The existence of this bug not only significantly empowers a -51% attacker, but also makes it notably harder to reason about miners' incentives. It could indeed -be in the interest of short-sighted miners as well as short-sighted users to exploit this -vulnerability in a small enough proportion to increase the block rate without fatally hurting the -network, as the effectively increased block space would — all other things being equal — bring fee -rates down for users. +The [timewarp bug][SE timewarp] makes it possible for a majority-hashrate attacker to arbitrarily +lower mining difficulty, and therefore arbitrarily increase the block rate. In the worst case, an +attacker can bring down the difficulty to its minimum within 38 days of starting the attack. Besides +empowering a 51% attacker, the presence of this bug makes it harder to reason about miners' +incentives. Accelerating the block rate allows an attacker to steal block subsidy from future +miners and increases available block space. It may be in the interest of short-sighted users and +miners to exploit this vulnerability to materially increase the block rate without fatally hurting +the network. Specially crafted blocks may be expensive to process, with validation times ranging from a few minutes up to more than an hour on lower-end devices. Long block validation times are a nuisance to