[bitcoin-dev] Getting around to fixing the timewarp attack.

[Zawy]

Rather than restricting every timestamp (or just the 2016*N+1
timestamps) to >= 1+ the previous timestamp as recorded on the
blockchain, the difficulty calculation could have the same restriction
but only in how the timestamps are used. I don't know about backwards
compatibility.  Either way, this would also prevent the powLimit
attack that is also capable of getting "unlimited" blocks in less than
4 weeks of > 50% selfish mining.  LTC, BCH, and LTC fixed to the
"Zeitgeist" or "timewarp" attack on GeistGeld in 2011 described by
Artforz in different ways, but all are still vulnerable by the
powLimit attack that I described here:
https://github.com/zawy12/difficulty-algorithms/issues/30

Other solutions may not prevent this other attack.