On Tue, Sep 13, 2011 at 11:06:37AM -0400, Gavin Andresen wrote: > Background: > > Timejacking: > http://culubas.blogspot.com/2011/05/timejacking-bitcoin_802.html > > And a recent related exploit launched against the low-difficulty > alternative chains: > https://bitcointalk.org/index.php?topic=43692.msg521772#msg521772
Here is an idea for an alternative (simple but hacky) solution: * Keep all network rules as they are now. * The timestamp value of mutliple-of-2016-blocks is set equal to the highest timestamp that occurred in the previous 11 blocks, instead of the current time. This will always obey the previous rules (it's always at least the median of the past 11 blocks, and never more in the future than them). Initially, roll out software that only uses this new rule for block creation, but doesn't enforce it. When enough miners have upgraded, choose a point in the future where it becomes mandatory (causing a block chain split only for those creating blocks using old software). If i understand the problem correctly, this will prevent an attacker from introducing a time lapse in between the 2015-block windows. One problem i do see, is that it prevents X-Roll-Time for miners. Maybe a short interval (1 minute? 10 minutes?) instead of a fixed value could be allowed for the multiple-of-2016 blocks. Comments? -- Pieter ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
