# Rain (RAIN) Quantum Readiness Report

> Rain has a QRI score of 0/100 and is assessed at Stage 0 (Unassessed / No Evidence) with medium evidence confidence.

Evaluation date: 2026-06-01. Review status: draft. Evaluated scope: ERC-20 governance token on Arbitrum L2; inherits host-chain cryptographic posture. Evaluation covers token-specific admin/governance keys and inherited Arbitrum/Ethereum ECDSA exposure..

Rain (RAIN) is a standard ERC-20 governance token deployed on Arbitrum One, a Layer-2 optimistic rollup on Ethereum. The token uses a UUPS-upgradeable proxy pattern with single-owner admin controls for minting, oracle configuration, and proxy upgrades. Per QRI Section 7.2 (Token Inheritance), RAIN inherits the full quantum vulnerability profile of its host chain: all transaction authorization, account ownership, and admin key operations rely on ECDSA/secp256k1 signatures verified by the Arbitrum/Ethereum execution layer. The project has published no cryptographic inventory, quantum threat model, PQC migration roadmap, or post-quantum design work of any kind. The Hacken audit (August 2025) confirms standard ERC-20 compliance and classical smart contract security but contains no quantum-specific review. Account abstraction via ERC-4337 (Alchemy smart accounts) provides gas sponsorship but does not alter the underlying ECDSA signature scheme. Arbitrum itself is independently assessed as Migration Stage 0 (Unaware) with QRI 26/100. The RAIN token has zero post-quantum protection at any layer and zero documented quantum readiness work.

## Core resources

- [Rain QRI report](https://qrindex.org/projects/rain/): Human-readable assessment with score, stage, evidence, blockers, risks, and assurance notes.
- [Rain structured report data](https://qrindex.org/projects/rain/report.json): Complete report as JSON for deterministic machine processing.
- [QRI methodology](https://qrindex.org/methodology/): Scoring model, evidence handling, readiness stages, confidence, assurance, and report status.
- [All QRI project reports](https://qrindex.org/llms.txt): Score-ranked index of every published project assessment.
- [Rain official website](https://rain.one): Project-maintained website.
- [Rain source repository 1](https://github.com/rainlanguage/rain-protocol): Project source code referenced by QRI.



## Evidence sources

- [Evidence source 1](<https://whitepaper.rain.one/>): Public source cited by the Rain QRI assessment.
- [Evidence source 2](<https://rain.one/>): Public source cited by the Rain QRI assessment.
- [Evidence source 3](<https://hacken.io/audits/rain/>): Public source cited by the Rain QRI assessment.
- [Evidence source 4](<https://github.com/rainlanguage/rain-protocol>): Public source cited by the Rain QRI assessment.
- [Evidence source 5](<https://arbiscan.io/token/0x25118290e6A5f4139381D072181157035864099d>): Public source cited by the Rain QRI assessment.
- [Evidence source 6](<https://hacken.io/audits/rain/sca-rain-token-aug2025/>): Public source cited by the Rain QRI assessment.
- [Evidence source 7](<https://github.com/rain1-labs/rain-sdk>): Public source cited by the Rain QRI assessment.
- [Evidence source 8](<https://coinmarketcap.com/currencies/rain/>): Public source cited by the Rain QRI assessment.