Once a bytestring representing >98% of the network is acquired by Alice or Bob, they begin the process of instantiating Ursula objects. Presently, instatiating the entire network in serial (without doing any metadata validation) takes about 6 seconds on my laptop, with most of the time spent in umbral.curvebn.from_int.

But generally, they don't need to instantiate all the Ursulas right then - let's optimize so that the batch_from_bytes method returns partially split bytes representations and constructs a dict by checksum address. I estimate this will instead only take about 30-60ms. Then, the Alice or Bob can instantiate the Ursulas as needed (and probably also work on the problem in another process).