discourse/discovery/INITIAL_CONCEPT.md

### System Overview

The goal is to create a platform where citizens can anonymously submit opinions on legislative matters, with those opinions influencing lawmakers, while guaranteeing transparency and security. Zero-Knowledge Proofs, a cryptographic tool, enable participants to prove eligibility and uniqueness without revealing their identities. The system integrates digital credentials, blind signatures, and ZKPs, optionally leveraging a blockchain for decentralization and auditability.

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### Key Features

1. **Anonymity**: Participants’ identities remain hidden, even from the system and authorities.
2. **Eligibility**: Only authorized individuals (e.g., citizens) can participate.
3. **Uniqueness**: Each participant submits only one opinion per legislative matter.
4. **Transparency**: All submissions and proofs are publicly verifiable.
5. **Security**: Cryptographic methods prevent fraud, manipulation, or duplicate submissions.

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### System Components

- **Participants**: Individuals with a digital credential (e.g., issued by a trusted authority based on citizenship).
- **Trusted Authority**: Issues credentials and blind signatures to ensure eligibility.
- **Public Ledger (Optional Blockchain)**: Stores commitments, submissions, and proofs for transparency and verification.
- **Legislative Matters**: Each matter (e.g., a proposed law) has a unique identifier, called a “matter ID.”

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### How the System Works

The system operates in two main phases: **Setup** and **Opinion Submission**.

#### 1. Setup Phase

For each legislative matter identified by a unique matter ID:

- **Credential Issuance**: Each participant has a digital credential from a trusted authority, proving eligibility (e.g., citizenship). This credential is private and tied to their identity initially but anonymized in later steps.
- **Token and Commitment Generation**:
    - For each matter, the participant generates:
        - A **unique token** (a random value specific to that matter).
        - A **secret key** (a private value known only to them).
    - They create a **commitment**—a cryptographic hash of the token and secret key combined with the matter ID. This commitment hides the token and key but can later be proven to match them.
- **Blind Signature Request**:
    - The participant sends the commitment and matter ID to the authority, with the token portion blinded (using a blind signature scheme like Chaum’s blind signatures).
    - The authority verifies that this credential hasn’t requested a signature for this matter ID before, then issues a **partially blind signature**. The signature includes the matter ID (visible to the authority) and the blinded commitment.
    - The participant unblinds the signature, obtaining a valid signature on their commitment tied to the matter ID.
- **Publishing Commitments**:
    - The participant publishes the commitment and its blind signature to a public ledger (e.g., a blockchain or database).
    - The authority ensures each credential gets only one signature per matter, limiting each participant to one commitment per matter.

At the end of the setup phase, there’s a public list of commitments for each matter, each with a valid blind signature, ensuring only eligible participants contribute exactly one commitment.

#### 2. Opinion Submission Phase

When a participant wants to submit an opinion on a legislative matter:

- **Submission Content**:
    - The participant reveals their **token** for that matter.
    - They provide their **opinion** (e.g., “yes,” “no,” or a short statement).
    - They generate a **Zero-Knowledge Proof (ZKP)** that proves:
        1. There exists a commitment in the public list for this matter ID where the revealed token matches the committed token.
        2. They know the secret key associated with that commitment.
- **Verification**:
    - The system (or a smart contract on a blockchain) verifies:
        - The commitment referenced by the ZKP has a valid blind signature from the authority.
        - The ZKP is correct, confirming the token’s legitimacy and the participant’s knowledge of the secret key.
        - The token hasn’t been used before for this matter (checked against a list of used tokens).
- **Recording**:
    - If valid, the system accepts the opinion, records it publicly with the token and ZKP, and marks the token as used.

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### Ensuring Core Requirements

- **Anonymity**:
    - Blind signatures ensure the authority doesn’t link commitments to participants.
    - The ZKP hides which commitment corresponds to the submission, mixing it among all participants’ commitments.
    - Tokens are unique per matter and unlinkable across matters, preventing profiling.

- **Eligibility**:
    - Only participants with a valid credential can obtain blind signatures and publish commitments.

- **Uniqueness**:
    - The authority issues one blind signature per credential per matter, limiting each participant to one commitment.
    - The ZKP and token check ensure each commitment submits only one opinion per matter.

- **Transparency**:
    - All commitments, signatures, opinions, tokens, and ZKPs are public. Anyone can verify that submissions correspond to valid commitments and that no token is reused.

- **Security**:
    - ZKPs require knowledge of the secret key, preventing token theft.
    - Blind signatures and commitments prevent the authority or outsiders from manipulating the process.
    - A blockchain (if used) ensures tamper-proof records.

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### Optional Blockchain Integration

For enhanced transparency and decentralization:
- **Commitments**: Stored as transactions on the blockchain during setup.
- **Submissions**: Each opinion submission is a transaction, verified by a smart contract that checks the ZKP and token uniqueness.
- **Auditability**: The blockchain provides a tamper-proof log, allowing anyone to audit the process without trusting a central entity.

This reduces reliance on a single authority, though the authority still issues initial credentials and signatures. A fully decentralized identity system could further minimize this dependency.

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### Scalability and Efficiency

- **Large Populations**: For millions of participants, the system manages large lists of commitments and used tokens. Modern databases or blockchains (e.g., Ethereum with rollups) can handle this scale.
- **Efficient ZKPs**: Using zk-SNARKs or zk-STARKs, proofs are small (e.g., a few hundred bytes) and verification is fast (e.g., milliseconds), making the system practical.
- **Setup Overhead**: Participants generate commitments per matter, which could be streamlined with reusable credentials, but the current design prioritizes security and simplicity.

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### Example Workflow

1. **Setup for Matter “Law123”**:
    - Alice, with credential C1, generates token T1 and secret key S1, commits to them as Com1 = Hash(T1, S1, “Law123”).
    - She gets a blind signature Sig1 from the authority on Com1 for “Law123” and publishes (Com1, Sig1).

2. **Submission**:
    - Alice submits her opinion “Yes” on “Law123” with:
        - Token T1.
        - ZKP proving T1 matches a commitment (e.g., Com1) and she knows S1.
    - The system verifies Sig1, the ZKP, and that T1 is unused, then records “Yes” with T1.

3. **Public Check**:
    - Anyone sees (Com1, Sig1) in the list, verifies Sig1, and confirms T1’s submission is valid and unique.

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### Conclusion

This system leverages ZKPs, blind signatures, and a public ledger to crowdsource public opinion securely and transparently. It ensures anonymity and fairness while allowing lawmakers to trust the authenticity of the input, making it a robust tool for democratic participation in legislation.