I think I figured out a proof of existance for a space efficient way to do better than bloom filters/prefix/bloom-bait. (Must have been dreaming on it as I woke up with the idea following Peter's suggestion to try prove instead if its possible or not:).
I wrote up the details here: https://bitcointalk.org/index.php?topic=431756.new In summary with a use of novel application of IBE (*) based on weil-pairing so the recipient can send a delegation private key that is specific to the block being queried. It means the node that services the query has no ability to correlate with queries in other blocks from the some user. The sender derives a pub=IBE-extract(master-pub, id=previous block hash). The above link has more explanation, links and costs/risks. I think it maybe within possibility to do further than this because it is not technically necessary to delegate decryption, only to delegate filtering, which can be a simpler requirement so there remains perhaps (speculatively) a possibility to do it without introducing weil pairing hardness problem or using eg I mentioned public key steganography or something like that if there is anything similarly efficient but with more widely used hardness assumptions. Adam (*) analogous to the way IBE is used as a building block for Non-Interactive Forward Secrecy (NIFS) On Fri, Jan 24, 2014 at 11:13:30AM -0500, Peter Todd wrote: >On Fri, Jan 24, 2014 at 04:42:35PM +0100, Adam Back wrote: >> Now while it would be clearly a very nice win if reusable addresses could >> be made SPV-like in network characteristics and privacy, but we dont have >> a plausible mechanism yet IMO. [...] >> >> If we can find some efficient crypto to solve that last one, we could even >> adopt them generally if it was efficient enough without needing interactive >> one-use address release. > >Conversely, it'd be interesting if someone can dig up a proof showing >that doing much better than Gregory's ambiguity tradeoff is impossible. ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
