mirror of https://github.com/zcash/orchard.git
5e6c8ae380
- Move Poseidon into the right-hand advice columns. The Action circuit
has 33 Sinsemilla invocations with 510-bit inputs (the 32 Merkle path
hashes, and Commit^ivk). Poseidon fits within the row count of one of
these invocations, so we can run it in parallel with these.
- Share fixed columns between ECC and Poseidon chips. Poseidon requires
four advice columns, while ECC incomplete addition requires six, so we
could choose to configure them in parallel. However, we only use a
single Poseidon invocation, and we have the rows to accomodate it
serially with fixed-base scalar mul. Sharing the ECC chip's 8 Lagrange
coefficient fixed columns instead reduces the proof size.
- We position Poseidon in the right-most 6 fixed columns, anticipating
a further optimisation to Sinsemilla that will occupy the left-most
2 fixed columns.
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| .. | ||
| ecc | ||
| poseidon | ||
| sinsemilla | ||
| utilities | ||
| ecc.rs | ||
| poseidon.rs | ||
| sinsemilla.rs | ||
| utilities.rs | ||