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Date: Sun, 10 May 2015 14:42:54 +0000
From: Bob McElrath <bob_bitcoin@mcelrath.org>
To: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
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Subject: Re: [Bitcoin-development] A suggestion for reducing the size of the
 UTXO database
Precedence: list

That's a lot of work, a lot of extra utxo's, and a lot of blockchain spam=
, just
so I can do a convoluted form of arithmetic on my balance.

If a tx contained an explicit miner fee and a change address, but did not
compute the change, letting the network compute it (and therefore merge
transactions spending the same utxo), could one add some form of ring sig=
nature
a la Dash to alleviate the worsened privacy implications?

Jeff Garzik [jgarzik@bitpay.com] wrote:
> This has been frequently explored on IRC.
>=20
> My general conclusion is "dollar bills" - pick highly common denominati=
ons of
> bitcoins.=A0 Aggregate to obtain these denominations, but do not aggreg=
ate
> further.
>=20
> This permits merge avoidance (privacy++), easy coinjoin where many hide=
 in the
> noise (privacy++), wallet dust de-fragmentation, while avoiding the
> over-aggregation problem where you have consolidated down to one output.
>=20
> Thus a wallet would have several consolidation targets.
>=20
> Another strategy is simply doubling outputs.=A0 Say you pay 0.1 BTC to
> Starbucks.=A0 Add another 0.1 BTC output to yourself, and a final chang=
e output.=A0
> Who can say which output goes to Starbucks?
>=20
> There are many iterations and trade-offs between fragmentation and priv=
acy.


--
Cheers, Bob McElrath

"The individual has always had to struggle to keep from being overwhelmed=
 by
the tribe.  If you try it, you will be lonely often, and sometimes fright=
ened.
But no price is too high to pay for the privilege of owning yourself."=20
    -- Friedrich Nietzsche