{"id":51430495,"url":"https://github.com/oxarbitrage/redpallas-formal","last_synced_at":"2026-07-05T03:30:43.293Z","repository":{"id":355049175,"uuid":"1226560505","full_name":"oxarbitrage/redpallas-formal","owner":"oxarbitrage","description":null,"archived":false,"fork":false,"pushed_at":"2026-05-01T15:03:56.000Z","size":9,"stargazers_count":0,"open_issues_count":0,"forks_count":0,"subscribers_count":0,"default_branch":"main","last_synced_at":"2026-05-01T17:09:00.958Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":null,"language":"Lean","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/oxarbitrage.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null,"notice":null,"maintainers":null,"copyright":null,"agents":null,"dco":null,"cla":null}},"created_at":"2026-05-01T14:58:18.000Z","updated_at":"2026-05-01T15:04:01.000Z","dependencies_parsed_at":null,"dependency_job_id":null,"html_url":"https://github.com/oxarbitrage/redpallas-formal","commit_stats":null,"previous_names":["oxarbitrage/redpallas-formal"],"tags_count":null,"template":false,"template_full_name":null,"purl":"pkg:github/oxarbitrage/redpallas-formal","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/oxarbitrage%2Fredpallas-formal","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/oxarbitrage%2Fredpallas-formal/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/oxarbitrage%2Fredpallas-formal/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/oxarbitrage%2Fredpallas-formal/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/oxarbitrage","download_url":"https://codeload.github.com/oxarbitrage/redpallas-formal/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/oxarbitrage%2Fredpallas-formal/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":35142824,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-05-26T15:22:16.424Z","status":"online","status_checked_at":"2026-07-05T02:00:06.290Z","response_time":100,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2026-07-05T03:30:42.728Z","updated_at":"2026-07-05T03:30:43.274Z","avatar_url":"https://github.com/oxarbitrage.png","language":"Lean","funding_links":[],"categories":[],"sub_categories":[],"readme":"# redpallas-formal\n\n**Status:** Fully proven — zero `sorry` statements.\n\nLean 4 formalization of the RedPallas signature scheme (RedDSA over Pallas) used for spend authorization and value binding in Zcash's Orchard protocol.\n\n## What's formalized\n\n- **`verify_sign`** — honest signatures always verify: [r + c·sk]·G = R + [c]·vk.\n- **`verify_rerandomized`** — signing with sk+α verifies against vk+[α]·G.\n- **`keygen_add`** — key generation is a group homomorphism: keygen(a+b) = keygen(a) + keygen(b).\n- **`two_fork_extract`** — Schnorr two-fork key extraction: from two valid transcripts with the same commitment but different challenges, extract the discrete log of the verification key.\n- **`binding_extractability`** — specialization to BindingSig: extracts `bsk` such that `bvk = [bsk]·BindingG`, matching the shape of [Ironwood](https://github.com/zcash/ironwood)'s `hExtract` hypothesis.\n\nUnforgeability (EUF-CMA) is **not** formalized — it requires a random oracle model not yet in Lean/Mathlib. The extractability theorems above prove the algebraic core; the forking lemma (Pointcheval–Stern) that produces the two transcripts in the ROM is not yet formalized.\n\n## Axioms\n\n| Axiom | Justification |\n|-------|--------------|\n| `order_pallas` | \\|Pallas(𝔽_p)\\| = q — same gap as `cycle_conjecture_pallas` in [pasta-formal](https://github.com/oxarbitrage/pasta-formal) |\n| `challengeHash` | BLAKE2b-based hash, opaque by design |\n| `G_ne_zero`, `BindingG_ne_zero` | Certified Zcash parameters |\n\n## Build\n\n```shell\nlake build\n```\n\n## Dependencies\n\nLean 4 (`v4.30.0-rc2`), [Mathlib4](https://github.com/leanprover-community/mathlib4), [pasta-formal](https://github.com/oxarbitrage/pasta-formal).\n\n## References\n\n- [Zcash Protocol Spec §5.4.6](https://zips.z.cash/protocol/protocol.pdf) — RedDSA\n- [ZIP-215](https://zips.z.cash/zip-0215)\n\n---\n\n## Part of a series\n\nSix repositories formally verifying the Zcash Orchard cryptographic stack:\n\n| Layer | Repository |\n|-------|-----------|\n| Curves | [pasta-formal](https://github.com/oxarbitrage/pasta-formal) |\n| Hash | [poseidon-formal](https://github.com/oxarbitrage/poseidon-formal) |\n| Hash-to-curve | [sinsemilla-formal](https://github.com/oxarbitrage/sinsemilla-formal) |\n| Signatures | [redpallas-formal](https://github.com/oxarbitrage/redpallas-formal) |\n| Protocol | [orchard-formal](https://github.com/oxarbitrage/orchard-formal) |\n| Proof system | [halo2-formal](https://github.com/oxarbitrage/halo2-formal) |\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Foxarbitrage%2Fredpallas-formal","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Foxarbitrage%2Fredpallas-formal","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Foxarbitrage%2Fredpallas-formal/lists"}