logos-storage-proofs-circuits/circuit

Storage proof circom circuit

See the README in the parent dir for the (draft) specification.

Organization of the circuit code

• codex - the storage proof circuit
• poseidon2 - Poseidon2 hash function
• lib - general purpose, reusable circom templates ("circuit library")

In codex:

• sample_cells.circom - compute cell indices to sample, and prove those cells
• single_cell.circom - prove a single cell
• merkle.circom - Merkle inclusion proof (using our custom Merkle tree convention)

In poseidon2

• poseidon2_hash.circom - compute Poseidon2 hash with sponge construction
• poseidon2_sponge.circom - generic sponge construction
• poseidon2_perm.circom - the Poseidon2 permutation
• poseidon2_compr.circom - the compression function

In lib:

• extract_bits.circom - extract lower bits of the standard representation of a field element
• binary_compare.circom - compare numbers given in binary representation (the point is that they can be bigger than the field size!)
• log2.circom - circom code for computing base 2 logarithm
• misc.circom - miscellaneous helper funtions

Main component

Note: the main component is not included in the above, as it depends on the parameters. You can use one of the reference input generators to create one; if you want to do manually, it should look like this:

pragma circom 2.0.0;
include "sample_cells.circom";

// argument conventions:
// SampleAndProven( maxDepth, maxLog2NSlots, blockTreeDepth, nFieldElemsPerCell, nSamples )
component main {public [entropy,dataSetRoot,slotIndex]} = SampleAndProve(32, 8, 5, 67, 100);