Do not allow overwriting unspent transactions #915

pull sipa wants to merge 1 commits into bitcoin:master from sipa:nooverwritetx changing 1 files +24 −2

sipa commented at 4:11 PM on March 3, 2012: member
Introduce the following network rule for blocks after march 15, 2012:
- a block is not valid if it contains a transaction whose hash already exists in the block chain, unless all that transaction's outputs were already spent before said block.
Warning: this is effectively a network rule change, with potential risk for forking the block chain. Leaving this unfixed carries the same risk however, for attackers that can cause a reorganisation in part of the network.

Thanks to Russell O'Connor and Ben Reeves.

in src/main.cpp:None in f955662da9 outdated

1250 | +    // being sent to another address.
1251 | +    // See http://r6.ca/blog/20120206T005236Z.html for more information.
1252 | +    // This logic is not necessary for memory pool transactions, as AcceptToMemoryPool
1253 | +    // already refuses previously-known transaction id's entirely.
1254 | +    // This rule applies to all blocks whose timestamp is after March 15, 2012, 0:00 UTC.
1255 | +    if (pindex->nTime > 1331769600)

gavinandresen commented at 4:57 PM on March 3, 2012:

Should you make it fTestNet || ... so it is running on testnet for a while before the switch on main net?

sipa commented at 4:59 PM on March 3, 2012:

That's possible, but enabling it for every block on testnet, will cause the current testnet chain to become invalid. I prefer switching testnet somewhere in the past, but after roconnor's tests.

sipa commented at 5:22 PM on March 3, 2012: member

Updated: enable on testnet since februari 20.

Do not allow overwriting unspent transactions (BIP 30)

Introduce the following network rule:
 * a block is not valid if it contains a transaction whose hash
   already exists in the block chain, unless all that transaction's
   outputs were already spent before said block.

Warning: this is effectively a network rule change, with potential
risk for forking the block chain. Leaving this unfixed carries the
same risk however, for attackers that can cause a reorganisation
in part of the network.

Thanks to Russell O'Connor and Ben Reeves.

a206b0ea12

gavinandresen referenced this in commit f2e81bad33 on Mar 3, 2012
gavinandresen merged this on Mar 3, 2012
gavinandresen closed this on Mar 3, 2012
coblee referenced this in commit 74157b6d78 on Jul 17, 2012
suprnurd referenced this in commit ee17056ddc on Dec 5, 2017
lateminer referenced this in commit 9c5a300624 on Oct 30, 2019
DrahtBot locked this on Sep 8, 2021

Contributors

sipa

gavinandresen