Implementation of chunk-level challenge/response according to Viktor Tron's Smash-Proof Paper.
To generate the audit hash for later challenge, each 4096 bytes chunk is chopped into 128 segments to form a Merkle Tree. Seed is then added to a random segment j. Aduit Secret Hash is defined as the Merkle Root of the Tree with salted segment j, which can be recovered/validated independently using the published seed.
This ASH implementaion is made to be compatible with swarmDB v0.1. Please be aware that it deliberately trims the padded 0
s prior to constructing the Tree, thus the ASH is different than the one specified in the paper.
TODO: pull-request to Viktor's BMT package