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From: Tamas Blummer <tamas@bitsofproof.com>
In-Reply-To: <CANEZrP2_9tRGpZ4gySHvohy0g2PsaQF9u+-tZ-bmn8JtgweihA@mail.gmail.com>
Date: Mon, 6 Oct 2014 05:22:51 -0700
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To: Mike Hearn <mike@plan99.net>
Cc: Bitcoin Development <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] The Bitcoin Freeze on Transaction Attack
	(FRONT)
Precedence: list

Note that the problem might arise also by a bug / accident and not as an =
attack.

Since value spent is not part of the signature it is easy to create an =
arbitrary fee by a defective wallet software.
Collecting that huge fee might provide a higher incentive to miner than =
the block subsidy on the trunk.

Assuming miner are fully rational, they might even form a temporary =
coalition to claim the fee:
The miner who mines forking block might offer part of the fee gained in =
a similar transaction to
other miners, so they help to extend his fork. A sufficiently high stake =
could trigger a long
fork =93battle=94 of ad-hoc coalitions.

Addressing the known bug of the signature hash, that it does not include =
the value spent,
would have other positive effects, e.g. for resource limited hardware =
wallets.

Interpretation of an OP_NOP for a value hashing signature check were =
suggested by Alan Reiner
discussed earlier on bitcointalk.

Tamas Blummer=