One Identity. Every Chain.

1.Abstract

2.Introduction

2.1 The Identity Fragmentation Problem

Blockchain technology promised trustless systems, yet users must repeatedly prove their legitimacy across every protocol. A whale on Jupiter has no reputation on Magic Eden. An active DAO voter on Realms starts fresh on every new governance platform. This fragmentation creates several critical issues:

• Users must repeatedly verify identity for each dApp
• Reputation doesn't transfer between protocols
• Proving activity requires exposing wallet addresses
• Multi-wallet users have no unified identity

2.2 NEXURA's Solution

NEXURA introduces a privacy-first identity layer that aggregates reputation across all your Solana wallets while keeping them private. Through zero-knowledge proofs, you can prove combined holdings, total activity, and cross-platform reputation without revealing individual wallet addresses.

3.Technical Architecture

NEXURA Protocol implements a four-layer architecture designed for security, privacy, and seamless integration with existing Solana protocols.

3.1 Wallet Linking Layer

The foundation of NEXURA allows users to privately link multiple Solana wallets to a single identity. Using zkSNARK proofs, users can prove ownership of wallets without revealing the addresses themselves. The linking process:

1. User signs a challenge message with each wallet
2. Signatures are processed through the ZK circuit
3. A commitment is generated linking wallets to identity
4. Only the user can generate proofs from this commitment

3.2 Reputation Aggregation Layer

NEXURA aggregates on-chain activity across linked wallets to build a unified reputation score. Data sources include:

• DeFi Activity: Jupiter, MarginFi, Drift, Kamino positions
• NFT Holdings: Magic Eden, Tensor collection data
• DAO Participation: Realms, Squads voting history
• Token Holdings: SPL token balances and staking

3.3 Attestation Generation

Users generate verifiable attestations about their aggregated reputation. Attestations are cryptographic proofs that can be verified on-chain without revealing underlying wallet data:

// Example Attestation Types
interface NexuraAttestation {
  type: "holdings" | "activity" | "membership" | "custom";
  claim: {
    threshold: number;
    comparison: "gte" | "lte" | "eq";
    metric: string;
  };
  proof: Uint8Array;
  expiry: number;
}

4.Cryptographic Primitives

4.1 Proof System: Plonk with KZG

NEXURA employs Plonk (Permutations over Lagrange-bases for Oecumenical Noninteractive arguments of Knowledge) with KZG polynomial commitments. This provides:

• Universal trusted setup (ceremony completed)
• Constant-size proofs (~256 bytes)
• Fast verification (~100ms on-chain)
• Recursive composition support

4.2 Hash Function: Poseidon

NEXURA uses Poseidon, a hash function specifically designed for ZK circuits. Benefits include:

• 8x fewer constraints than SHA-256 in circuits
• Algebraic structure optimized for SNARKs
• Proven security under standard assumptions

4.3 Identity Commitments

Wallet linking uses Pedersen commitments for hiding wallet addresses:

5.Implementation

5.1 Solana Program

The NEXURA on-chain program is built with Anchor framework, providing:

// nexura-protocol/programs/nexura/src/lib.rs
use anchor_lang::prelude::*;

#[program]
pub mod nexura_protocol {
    use super::*;

    pub fn create_identity(
        ctx: Context<CreateIdentity>,
        commitment: [u8; 32],
    ) -> Result<()> {
        let identity = &mut ctx.accounts.identity;
        identity.owner = ctx.accounts.owner.key();
        identity.commitment = commitment;
        identity.created_at = Clock::get()?.unix_timestamp;
        Ok(())
    }

    pub fn verify_attestation(
        ctx: Context<VerifyAttestation>,
        proof: Vec<u8>,
        public_inputs: Vec<u8>,
    ) -> Result<bool> {
        // Groth16 verification logic
        verify_proof(&proof, &public_inputs)
    }
}

5.2 SDK Integration

NEXURA provides comprehensive developer tooling:

// TypeScript SDK Example
import { Nexura } from '@nexura-protocol/sdk';

const nexura = new Nexura({ network: 'mainnet-beta' });

// Create identity with linked wallets
const identity = await nexura.createIdentity({
  wallets: [wallet1, wallet2, wallet3],
});

// Generate attestation
const attestation = await nexura.generateAttestation({
  type: 'holdings',
  claim: { metric: 'total_sol', comparison: 'gte', threshold: 100 },
});

// Verify on-chain
const verified = await nexura.verifyAttestation(attestation);

6.Use Cases

6.1 DeFi Lending

Prove combined holdings across wallets for better borrowing rates without doxxing your full portfolio. A user with $100k across 5 wallets can prove this threshold without revealing individual balances.

6.2 NFT Communities

Collectors can prove ownership across multiple wallets to access exclusive communities. A collector with 50 NFTs spread across wallets can prove "whale" status without revealing their collection.

6.3 DAO Governance

Aggregate voting power from multiple wallets while maintaining privacy. Prove participation across Realms, Squads, and other governance platforms for reputation-weighted voting.

6.4 Airdrop Qualification

Projects can verify user activity without wallet exposure. Users prove they meet criteria (volume, holdings, participation) without revealing which wallets qualify.

7.Security Considerations

7.1 Threat Model

NEXURA considers the following adversarial scenarios:

• Wallet Correlation: Preventing linking of wallet addresses through timing or pattern analysis
• Proof Forgery: Ensuring only legitimate wallet owners can generate attestations
• Replay Attacks: Preventing reuse of attestations across contexts
• Front-running: Protecting proof submission from MEV extraction

7.2 Audit Status

NEXURA smart contracts and ZK circuits are audited by leading security firms:

• Smart Contract Audit: Pending (Q1 2025)
• ZK Circuit Audit: Pending (Q1 2025)
• Bug Bounty: Launching with mainnet

8.Tokenomics

The NEXURA token serves multiple functions within the protocol ecosystem:

8.1 Utility

• Attestation Fees: Proof generation and verification fees paid in NEXURA
• Staking: Validators stake NEXURA as collateral for reputation aggregation
• Governance: Token holders vote on protocol parameters and upgrades
• Premium Features: Advanced attestation types and priority processing

8.2 Distribution

9.Roadmap

10.Conclusion

References

1. Gabizon, A., Williamson, Z., Ciobotaru, O. "PLONK: Permutations over Lagrange-bases for Oecumenical Noninteractive arguments of Knowledge" (2019)
2. Grassi, L. et al. "Poseidon: A New Hash Function for Zero-Knowledge Proof Systems" (2019)
3. Ben-Sasson, E. et al. "Scalable, transparent, and post-quantum secure computational integrity" (2018)
4. Solana Foundation. "Solana Program Library" (2024)
5. Buterin, V. "An incomplete guide to stealth addresses" (2023)