NERO Auth API

The MPC backend powering embedded wallets. True threshold ECDSA signing where the private key is never reconstructed — at every tier, including Free.

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How key generation works

A 3-round commit-reveal protocol based on the DKLS paper. Neither party can cheat — Schnorr proofs verify correct execution at every step.

Backend Commitment

Backend generates random scalar sk_B, computes public point P_B = sk_B × G, and sends commitment SHA256(P_B) to the client. Commitment prevents adapting sk_B after seeing the client's share.

Proof Exchange

Both parties reveal their public points with Schnorr proofs of knowledge (Fiat-Shamir). Each side proves it knows the discrete log of its public point — no forgery possible.

Joint Key Derivation

Joint public key: P = sk_A × sk_B × G. Wallet address: keccak256(P)[12:]. The backend stores sk_B in HSM (AES-256-GCM). The full private key sk = sk_A × sk_B is never assembled.

Why true MPC matters

Unlike competitors that reconstruct the private key during signing, NERO uses threshold ECDSA — only partial signatures exist. The full key is never assembled at any point in the signing flow.

	NERO (DKLS)	Web3Auth (SSS)	Custodial
Key reconstructed during signing	Never	Yes (client-side)	Yes (server-side)
Protocol	5-round MtA threshold ECDSA	Shamir reconstruct → local ECDSA	Server signs on behalf of user
Backend compromise	sk_B alone is useless	1-of-3 share exposed	Full key stolen
Client compromise	sk_A alone is useless	1-of-3 share exposed	Full key stolen
True MPC at Free tier	Yes	SSS only (not MPC)	N/A

13 core features

Every feature is production-ready and fully implemented. True MPC threshold signing is available at every tier — no enterprise paywall for security.

2-Party MPC Key Generation

All tiers

DKLS threshold ECDSA keygen with Schnorr proofs. Backend generates sk_B, client generates sk_A. Joint public key derived as P = sk_A × sk_B × G. Private key never assembled on any machine.

Threshold ECDSA Signing

All tiers

5-round Multiplicative-to-Additive protocol. Partial signatures computed independently — full private key is never reconstructed during signing. Standard ECDSA output compatible with all EVM chains.

Social Login (9 Providers)

All tiers

Google, GitHub, Apple, Discord, Facebook, LINE, LinkedIn, Twitter/X, WeChat. NERO-managed credentials on Growth+, or bring your own OAuth app on Free.

Custom JWT Verification

Growth+

Validate tokens from Auth0, Firebase, AWS Cognito, or any OIDC provider. Users authenticate with your existing auth system — NERO adds the wallet layer.

Aggregate Verifiers

Growth+

Link multiple login methods to the same wallet via shared email. Google + GitHub + custom JWT all resolve to the same address for the same user.

Multi-Factor Authentication

Growth+

TOTP (authenticator apps) on Growth+, FIDO2 WebAuthn (fingerprint/security keys) on Scale+. MFA can gate recovery, key rotation, and high-value signing operations.

Device Trust & Verification

All tiers

Device fingerprinting classifies devices as new, pending, or trusted. New devices require OTP verification. Sensitive operations require a trusted device.

Time-Locked Account Recovery

Scale+

48-hour anti-theft time-lock. Three recovery methods: password-based, trusted device backup, and BIP-39 seed phrase. Recovery cannot complete before the lock period expires.

Encrypted Key Share Backup

All tiers

Export key shares encrypted with scrypt KDF + AES-256-GCM. User stores the encrypted blob offline. Restore via import endpoint — no NERO access to plaintext shares.

Key Material Export

Growth+

Backend delivers its share (sk_B) to the SDK via ephemeral ECDH encryption. Client reconstructs the full key locally for offline signing or wallet migration. Rate-limited.

Self-Custody Recovery

Scale+

Full exit protocol — user decrypts both shares and computes sk = sk_A × sk_B. Import the private key into MetaMask or any standard wallet. Works without NERO online.

Distributed Node Infrastructure

Enterprise

Backend share sk_B split via Shamir's Secret Sharing across N nodes with T-of-N threshold. HMAC-authenticated node-to-node communication. Commitment verification on every reconstruction.

Audit Logging & Compliance

All tiers

Every signing, recovery, export, and device operation logged with user ID, wallet address, IP, action, and timestamp. Queryable API with date range and action filters.

True MPC at every tier

Competitors gate threshold cryptography behind enterprise pricing. NERO gives every developer — from a free prototype to a scaled production app — the same 2-party DKLS threshold ECDSA. The private key is never reconstructed for any customer, at any plan.

HSM Protection

Server key shares wrapped by AWS KMS or GCP Cloud KMS. Key material never leaves the hardware security module.

11-Layer Middleware

Request ID, logging, Helmet CSP, API versioning, device ID, content validation, size limits, global rate limiting, API key auth, CORS, per-key rate limiting.

Zero-Knowledge Proofs

Schnorr proofs of knowledge on every keygen round. Feldman VSS commitments for Pedersen DKG. Configurable enforcement mode: off, audit, or enforce.

Start building with NERO Auth

Create a project, get an API key, and integrate the SDK. Your users get self-custodial wallets in seconds.