A space-efficient sub-graph description of IOTA’s tangle.
How best to describe what I am trying to by quoting the problem statement from Serguei Popov?
From the #tangle-math discord channel on 20–11–2018:
Serguei Popov [IF]11/20/2018: “Let me call it “semipermanode problem”. It is of course difficult to store all the transaction since the beginning, since it requires a lot of space. On the other hand, many of those transactions need not be stored, because they are almost/completely useless (e.g. spam). Assume that you want to store only a specific set of transactions: say, the historical data from the temperature sensors captured in the center of Munich (which is of course important and needs to be stored forever since you believe that many people or entities will need it in the future). To prove that that data is genuine, you don’t need to store the whole Tangle; you just need a connected (to the “present time”) subgraph of the Tangle which contains the transactions of the interest. So, question: how to…