1 2016-03-08 14:07:37 <Chris_Stewart_5> Does BitcoinJ implement SPV exactly in the way that is described in Satoshi's white paper?
 2 2016-03-08 14:09:13 <instagibbs> Chris_Stewart_5, depends what you mean. It checks header difficulty, and for inclusion of transactions it owns in blocks by asking peers, but there are no fraud proofs.
 3 2016-03-08 14:11:20 <Chris_Stewart_5> instagibbs: Is this reason they don't have fraud proofs because of the same reason we require a soft fork for sidechains?
 4 2016-03-08 14:11:30 <Chris_Stewart_5> or is it a limitation in bitcoinj?
 5 2016-03-08 14:12:16 <instagibbs> they were never developed in Bitcoin, so bitcoinj can't use them
 6 2016-03-08 14:12:21 <instagibbs> for various reasons
 7 2016-03-08 14:12:52 <instagibbs> gtg, but here's an email talking a bit about fraud proofs: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-November/011817.html
 8 2016-03-08 14:12:59 <Chris_Stewart_5> instagibbs: Thanks
 9 2016-03-08 16:27:56 <Luke-Jr> Chris_Stewart_5: fraud proofs are pretty much "impossible"
10 2016-03-08 16:49:32 <Chris_Stewart_5> Luke-Jr: Care to elaborate more? Due to space requirements for the fraud proofs?
11 2016-03-08 16:54:38 <Luke-Jr> Chris_Stewart_5: it is always possible to make a bogus SPV proof that cannot be proven to be bogus, by withholding the invalid part of the block from everyone
12 2016-03-08 16:56:09 <Chris_Stewart_5> Luke-Jr: So this attack could only be performed by miners that just minted a fresh block? if you were an SPV node couldn't you just query other nodes asking for the block?
13 2016-03-08 16:56:29 <Luke-Jr> Chris_Stewart_5: fraud proofs are needed to protect against miners making invalid blocks
14 2016-03-08 17:04:55 <Chris_Stewart_5> Luke-Jr: Invalid for any reasons? Invalid signatures, invalid block size, too many sigops... etc?
15 2016-03-08 17:05:11 <Luke-Jr> yes
16 2016-03-08 17:07:08 <Chris_Stewart_5> Thanks for the explanation
17 2016-03-08 23:41:36 <wallet42> how many orphan blocks does bitcoind keeps and for how long?