Precomputed variant should work with a threshold number of shares and not need all of them

[cygnusv]

No description provided.

[piotr-roslaniec]

This issue is caused by precomputed decryption shares using all domain points of all participants for Lagrange coefficients (pre)computing.

According to the docs:

(...) you will first choose a specific sub-set of m nodes from n i.e pick an arbitrary m-of-n set of nodes (where m is the threshold), and those specific m nodes need to reply with precomputed decryption shares (...)

So in order to fix this, I will expose an interface where the caller (tDec decryption client) can specify said subset of participants to have decryption shares created for them.

[piotr-roslaniec]

Closed by #185