On Apr 7, 2017 12:42, "Gregory Maxwell" wrote: On Fri, Apr 7, 2017 at 6:52 PM, Tom Harding via bitcoin-dev wrote: > A network in which many nodes maintain a transaction index also enables a > class of light node applications that ask peers to prove existence and > spentness of TXO's. Only with the additional commitment structure such as those proposed by Peter Todd in his stxo/txo commitment designs, e.g. https://petertodd.org/2016/delayed-txo-commitments Light nodes are improved by detecting invalid transactions, even before they are mined.