Solution: LP-0003 Private Allowlist / Airdrop Distributor

[edenbd1]

A distributor commits an eligibility set on chain. An eligible recipient claims
their allocation without revealing which entry is theirs — not to observers, and
not to the distributor.

• Repo: https://github.com/edenbd1/lp-0003-private-airdrop-distributor
• Video: https://youtu.be/mI33jjqxlZE
• Solution file: solutions/LP-0003.md

What is verified on chain

A claim travels on LEZ's privacy-preserving path, carrying a real STARK receipt
the sequencer checks against the node-pinned PRIVACY_PRESERVING_CIRCUIT_ID.
What lands is a single marker account whose address is
SHA256(prefix ‖ distribution_id ‖ nullifier), where the nullifier is derived
from the recipient's secret. An observer who knows every candidate address still
cannot compute the nullifier, so no marker maps back to a recipient.

Evidence, on the current public testnet

claim program	4a8dab271c2ac4f3b19c38b45e3f05fa4f413a0ac84a7b28030abebc8c5fdf59
verifier program	90f615d4045db10c2e42c44d15bf80f36a7a72e31df51e3bda6c46e4a22defe7
claim (privacy tx)	d9236824835c9f6a986c3bc687c04e2c722ad0984009fb0a936767d3c584e13b

curl -s -X POST https://testnet.lez.logos.co -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"getTransaction","params":["<hash>"]}'

The two program hashes are SHA256(borsh(bytecode)) of the binaries committed in
the repository, so they can be recomputed without trusting this table.
./scripts/verify-onchain-claim.sh runs five checks against the live chain,
ending at "the marker PDA is owned by the verifier program" — which no
transaction lookup can fake.

The video shows a fresh claim being proved and submitted during the recording,
with RISC0_DEV_MODE=0 visible before any proving starts, and the same five
checks passing against it afterwards.

Beyond the unit tests

docs/onchain-audit.md records three adversarial demonstrations run against the
live deployed programs rather than against a local harness: a claim that does
not genuinely prove membership, one that redirects its allocation, and one that
replays a spent nullifier. All three are rejected on chain.

Against the criteria

29 tests, CI green, including a workflow that runs the whole lifecycle against a
real standalone LEZ sequencer with RISC0_DEV_MODE=0. CU costs are measured per
instruction. The Basecamp module ships as a .lgx with darwin-arm64 and
linux-amd64 variants; scripts/package-lgx.py --verify recomputes every manifest
hash from the archive's own contents, and the video shows that check passing.

Happy to address anything in review.

[github-actions]

✅ Validation passed

A reviewer will assess against the prize criteria.
ℹ️ Solution submission for LP-0003.
ℹ️ Checking repo: https://github.com/edenbd1/lp-0003-private-airdrop-distributor

---

Automated check. See solution template and TERMS.