--- Day changed Tue Jan 30 2018 00:01 < kallewoof> I'm testing out addition of pubkeys / privkeys, but am unable to find a function in secp256k1 that lets me add two pubkeys together. (There are versions that add scalars, though.) Do I have to convert them before adding them together somehow? 00:03 < kallewoof> Closest one I found was secp256k1_eckey_privkey_tweak_add but it takes a secp256k1_scalar, and I'm not even sure what the 'tweak' part of the function name means. 00:07 < gmaxwell> libsecp256k1 is not a cook your own crypto construction set, at least not from the public interface. There isn't a generic function to add public keys, because that isn't a useful cryptographic protocol by itself. (e.g. if you try to build multisig from that alone you'll expose yourself to rogue key attacks). 00:07 < gmaxwell> you can easily construct it from the internal interfaces, though. 00:08 < gmaxwell> privkey tweaking adds two private keys, pubkey tweeking is P + xG which are the basic operations used e.g. for BIP32 usage. 00:11 < kallewoof> Gotcha. I'll dig around. 00:13 < gmaxwell> actually secp256k1_ec_pubkey_combine will add pubkeys for you. forgot we had that. (not I don't remember WHY we have it) 00:14 < gmaxwell> but there you go 00:14 < kallewoof> *blinks* Yeah, I'm blind. Thanks! 01:14 -!- jtimon [~quassel@41.31.134.37.dynamic.jazztel.es] has joined #secp256k1 02:05 < waxwing> gmaxwell, maybe public derivation in bip32? 02:06 < gmaxwell> no, thats pubkey_tweak 02:07 < waxwing> ah right 02:08 < gmaxwell> it was part of the schnorr code and we forgot to strip it when we removed it. 02:54 -!- jtimon [~quassel@41.31.134.37.dynamic.jazztel.es] has quit [Ping timeout: 248 seconds] 06:04 -!- jtimon [~quassel@41.31.134.37.dynamic.jazztel.es] has joined #secp256k1 15:45 -!- luke-jr [~luke-jr@unaffiliated/luke-jr] has quit [Read error: Connection reset by peer] 15:50 -!- luke-jr [~luke-jr@unaffiliated/luke-jr] has joined #secp256k1 16:50 -!- kallewoof [~karl@fp96f94c66.tkyc515.ap.nuro.jp] has quit [Read error: Connection reset by peer] 16:51 -!- kallewoof [~karl@240d:1a:759:6000:a7b1:451a:8874:e1ac] has joined #secp256k1 17:44 -!- mryandao [~mryandao@unaffiliated/mryandao] has left #secp256k1 [] 18:08 -!- droark [~droark@c-24-22-123-27.hsd1.or.comcast.net] has quit [Ping timeout: 240 seconds] 18:35 -!- mryandao [~mryandao@unaffiliated/mryandao] has joined #secp256k1 18:53 -!- droark [~droark@c-24-22-123-27.hsd1.or.comcast.net] has joined #secp256k1 19:07 -!- mryandao [~mryandao@unaffiliated/mryandao] has left #secp256k1 [] 19:23 -!- TD-Linux [~Thomas@about/essy/indecisive/TD-Linux] has quit [Ping timeout: 255 seconds] 19:24 -!- TD-Linux [~Thomas@about/essy/indecisive/TD-Linux] has joined #secp256k1 19:34 -!- mryandao [~mryandao@unaffiliated/mryandao] has joined #secp256k1 21:05 -!- arubi [~ese168@gateway/tor-sasl/ese168] has quit [Ping timeout: 255 seconds] 21:06 -!- arubi [~ese168@gateway/tor-sasl/ese168] has joined #secp256k1 21:10 -!- arubi [~ese168@gateway/tor-sasl/ese168] has quit [Remote host closed the connection] 21:10 -!- arubi_ [~ese168@gateway/tor-sasl/ese168] has joined #secp256k1 21:11 -!- mryandao [~mryandao@unaffiliated/mryandao] has left #secp256k1 [] 21:14 -!- arubi_ [~ese168@gateway/tor-sasl/ese168] has quit [Remote host closed the connection] 21:15 -!- arubi [~ese168@gateway/tor-sasl/ese168] has joined #secp256k1 21:26 -!- mryandao [~mryandao@unaffiliated/mryandao] has joined #secp256k1 21:27 -!- mryandao [~mryandao@unaffiliated/mryandao] has left #secp256k1 [] 23:35 -!- jtimon [~quassel@41.31.134.37.dynamic.jazztel.es] has quit [Ping timeout: 240 seconds]