No, anyone with the bip32 public seed can do the same as the receiver as "watch only". The only difference is rhat the receiver can actually spend the coins. As gmaxwell explained, if it's expensive for everyone, it will be also expensive for the receiver (assuming no interaction after the bip32 public seed is transfered).
Something different would be to give a different bip32 public seed to each payer. That way they can simply start with zero an increment with each new payment. With those assumptions, the receiver could start listening to new addresses only after they receive something in the previous address. Probably not useful for this case, just thinking out loud about using bip32 public seeds instead of one use addresses when there's going to be several payments from the same payer to the payee. On Aug 12, 2016 2:37 PM, "Erik Aronesty via bitcoin-dev" < bitcoin-dev@lists.linuxfoundation.org> wrote: > > I'm imagining a "publishable seed" such that: > > - someone can derive a random bitcoin address from it - and send funds to it. > - the possible derived address space is large enough that generating all possible addresses would be a barrier > - the receiver, however, knowing the private key, can easily scan the blockchain fairly efficiently and determine which addresses he has the keys to > - another interested party cannot easily do so > > Perhaps homomorphic encryption may need to be involved? > > > On Thu, Aug 11, 2016 at 8:36 PM, Gregory Maxwell <g...@xiph.org> wrote: >> >> On Thu, Aug 11, 2016 at 8:37 PM, Erik Aronesty via bitcoin-dev >> <bitcoin-dev@lists.linuxfoundation.org> wrote: >> > Still not sure how you can take a BIP32 public seed and figure out if an >> > address was derived from it though. I mean, wouldn't I have to compute all >> > 2^31 possible public child addresses? >> >> Which would take a quad core laptop about 8 hours with competent software >> >> And presumably you're not using the whole 2^31 space else the receiver >> also has to do that computation... > > > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >
_______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
