hash_piece() is an internal API, which means its caller hash_message()
is working in the same region. We rely on the caller to have already
assigned each piece's initial x_a at the correct offset before making
the call to hash_piece().
Co-authored-by: Jack Grigg <jack@electriccoin.co>
This toggles the assignment of q_s2 on the last row of each piece.
We assign q_s2 = 2 on the last row of the final piece, and q_s2 = 0
on the last row of other pieces.
This allows us to process the final_piece in the main loop together
with the other pieces.
Co-authored-by: Jack Grigg <jack@electriccoin.co>
Also, GeneratorTable::configure() was not being called in the main
SinsemillaChip::configure(), which meant the lookup argument had
not been activated. This has now been fixed.
Co-authored-by: Jack Grigg <jack@electriccoin.co>
witness_message() witnesses a full message given a bitstring.
The other two APIs, witness_message_piece_bitstring() and
witness_message_piece_field(), both witness a message piece, i.e.
part of a message that fits within a single base field element.
witness_message_piece_bitstring() takes in a bitstring, while
witness_message_piece_field() takes in a field element. In the
latter case, the number of words encoded must be specified.
This defines a Sinsemilla message in terms of pieces and subpieces.
This is useful when decomposing field elements and packing them
into K-bit messages.
therealyingtong