From: Elden Tyrell <tyrell.elden@gmail•com>
To: bitcoin-development@lists•sourceforge.net
Subject: [Bitcoin-development] does "stubbing" off Merkle trees reduce initial download bandwidth?
Date: Sun, 1 Jan 2012 21:04:03 -0800 [thread overview]
Message-ID: <jdrds3$3tf$1@dough.gmane.org> (raw)
Satoshi's paper mentions that storage requirements for the blockchain
can be reduced by deleting transactions whose outputs have been spent.
If I understand correctly, this technique can only be used for reducing
*storage* requirements, not *bandwidth* needed for the initial chain
download by a high-security client that doesn't trust any of its peers
-- right?
The rule is "trust the longest valid chain of blocks". Part of a block
being "valid" is that each transaction's inputs are unspent and their
sum exceeds the transaction's outputs unless it is a coinbase. This
cannot be verified for "stubbed out" transactions -- they have outputs
but no inputs, and aren't coinbases. So a paranoid client booting up
for the first time needs to be given an un-stubbed chain, right?
Of course, if a client decided to accept a stubbed blocks only when the
sum of the difficulties in the blocks after it exceeds some number N,
then attacking it could be made very expensive by picking a large
enough N.
Please let me know if I have misunderstood something.
next reply other threads:[~2012-01-02 5:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-02 5:04 Elden Tyrell [this message]
2012-01-02 13:31 ` Christian Decker
2012-01-02 22:23 ` Elden Tyrell
2012-01-02 22:41 ` Gregory Maxwell
2012-01-03 1:39 ` Elden Tyrell
2012-01-05 23:30 ` Mike Hearn
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