Transcript for #bitcoin-dev 2017/09/19

01:41 cluelessperson petertod d's bitcoinlib doesn't support segwit yet. so my bot doesn't find it
01:44 cluelessperson I'll do some stuff
14:17 knaccc gmaxwell I'm a contributor to Monero, and we were wondering if you might be willing to give us your quick thoughts on the statement you made in your CT paper: "Most importantly, this scheme is compatible with pruning and does not make the verification state for Bitcoin grow forever". We were wondering if you'd agree that it would make sense for Monero to prune all ring signatures and range proofs after a
14:17 knaccc period of, say, 60 days, without putting the blockchain at risk.
15:23 nikhatzi Hello ppl. I'm following the gitian-building guide from github, but for some reason everytime I fail to build bitcoin-qt. It says that lqwindows cannot be found and it won't build the bitcoin frontend. Any help?
18:03 dviola when making backups, are there any downsides/disadvantages to overwriting old backups with new ones?
18:04 dviola and is this even recommended?
18:04 dviola so I don't have to create different copies of the backup files, e.g. wallet-2017-09-19.dat, etc
18:06 esotericnonsense dviola: one disadvantage of overwriting is that if they're not 'of the same wallet' (e.g. you had some other wallet.dat) then you could nuke the wrong one by mistake
18:07 esotericnonsense dviola: it shouldn't be necessary to constantly back it up if it's a HD wallet though, you will lose new labels and such but that's all
18:11 dviola esotericnonsense: you mean that opening a wallet.dat that was created by an older version of core and overwriting that with a newer version could result in a problem?
18:12 esotericnonsense dviola: no, i mean that you mix up actually different wallets
18:12 dviola hrm
18:13 dviola I don't think I'll ever do that, I'll probably be on the latest version most of the time
18:15 dviola but yeah, I see now why it could be a good thing to have different backup copies like that
18:16 dviola thanks
18:40 dviola esotericnonsense: by 'different wallets' do you mean loading different wallet.dat at the same time or different versions of Core on different computers?
18:42 esotericnonsense dviola: i mean actually different wallets with different addresses in
18:43 esotericnonsense in the HD case, wallets which have different seeds
18:43 dviola oh
18:44 esotericnonsense (and also different addresses, just trying to make clear what I mean by different, no set overlap)
18:45 dviola it makes sense now, thanks
18:45 dviola I only have one address right now, in that case overwriting can't be a problem right?
18:45 dviola err
18:45 dviola one wallet
18:50 esotericnonsense it's really up to you. one thing i would say is that testing backups could be useful here.
18:55 esotericnonsense an amusing thing - there's been at least one airdrop that i wasn't aware of until recently. clam coin - if you had a balance in an address in may 2014 then you could get some. they actually have a value (bonkers).
18:57 esotericnonsense missed the cutoff here but it was vaguely similar to BCH (except instead of balances carrying over 1:1, there was a fixed amount per 'live' address).
18:58 esotericnonsense who knows, maybe you'll learn of a silly altcoin but you've already deleted an old wallet cause it was empty. unlikely but eh.
19:06 arubi "oops I sent to one of your old addresses by mistake teehee"
19:06 arubi "what do you mean gone?"
19:16 esotericnonsense oh yeah, that too
19:16 esotericnonsense *poof*
19:31 dviola I don't see how I could lose anything if I have only 1 wallet and I overwrite the backups
19:31 arubi you might overwrite that file one time with a corrupt wallet
19:32 arubi then there's no going back and you need a new one
19:32 arubi say there wasn't a lot in it, but still people have these addresses. they're not supposed to pay to them, you're not supposed to use them, but anything can happen
19:34 dviola I see
19:34 dviola good point
19:35 ossifrage dviola, storage is free, just save multiple backups (I save all my backups)
19:35 dviola yep, thanks
19:36 ossifrage The wallet files are tiny, you can fit a shitload of wallet.dat files in a $10 USB key, so why not just save every backup
19:37 dviola I will
19:46 dviola storage is not my problem, what if you add the name of the file wrong and then you have trouble finding out "what was the most recent backup I had?"
19:46 dviola could that be an issue?
19:46 esotericnonsense stat wallet*.dat
19:46 esotericnonsense also you could create a script to name it
19:48 esotericnonsense make the backup, mv -i wallet.dat{,.$(date +"%Y%m%d")}
19:48 arubi "/path/to/bkp/wallet.dat.$(date '+%d_%m_%y_%H_%M')"
19:49 arubi it's probably also written in the wallet.dat file itself if you dump it with bdb tools :)
19:51 esotericnonsense yeah
19:52 esotericnonsense i was kind of thinking that it'd be nice to have wallet.dat automatically name itself based on some characteristic like a hash of the seed (then it's harder to mix them up), but it's complicated because wallets can have all sorts in them
19:53 esotericnonsense you do it and then someone goes and imports a privkey and suddenly 'wallet-abcde.dat' is no longer covered by an old 'wallet-abcde.dat' backup
19:54 arubi most grief is due to a cumbersome restore method I think
19:54 dviola thanks guys
19:55 arubi now with HD wallets you could technically get everything back (well, keys and transactions only really)
19:55 arubi still need a proper procedure for the metadata and scripts if you use any, that has to be done with timely backups still
19:57 arubi really it all comes down to what the wallet is willing to consider as "yours" and for it to be able to solve that interesting "mine" script on its own so it'll tell me "these are your coins"
19:57 arubi with bare pubkeys, canonical scripts, easy. p2(w)sh? doh.
20:29 privateglacier Hi guys, I extended Glacier protocol (a python script that uses Bitcoin Core for storing multi-sig bitcoin private key securely) with some security improvements, but I wasn't able to find a person to review my small change so far, because none of my friends understand Bitcoin enough. Do you have some suggestions who I could ask to review it? The code change is here (only the is interesting):
20:29 privateglacier