[ZcF-general] Grant project progress report: Riemann

[James Prestwich]

Dear all,

We expected grants to be awarded sooner, so by the time the grants were
announced, we had largely achieved our original goals
<https://github.com/ZcashFoundation/GrantProposals-2018Q2/issues/19>.
Riemann <https://github.com/summa-tx/riemann> supports Sapling and
Overwinter. Recent work includes the release of riemann-tx==1.1.6, which
includes a sapling transaction construction example
<https://github.com/summa-tx/riemann/blob/d4b251e3972ff8614082de90f65ffa890b7b1e74/riemann/examples/sapling_example.py>
and
a number of sapling-related bugfixes
<https://github.com/summa-tx/riemann/pull/91>. The transaction construction
example was used this afternoon to build c895...5b6d
<https://explorer.zcha.in/transactions/c8951c6c488a13b9bad1b7a76af70d30a4d7b80abd503143b0824dc98bc95b6d>
to
sweep one of my old wallets.

With respect to proof verification, we are currently blocked, and have been
from some months. We need access to the Sapling and Sprout proving and
verifying keys in an easily consumable fashion. If anyone familiar with the
file formats involved can grab and document those group elements, please
reach out directly.

Going forward, we'll update with at least one significant usage example
each month.

Best,
James