Signia: Next-Generation Passwordless, Crypto-Powered SSO

1. Abstract

Modern applications require secure, user-friendly authentication mechanisms. While traditional solutions (Auth0, Okta, etc.) simplify single sign-on (SSO) and centralized identity management, they remain vulnerable to phishing, password reuse, and single points of failure. Simultaneously, web3 technologies promise user-controlled keys and decentralized identities but often burden users with complex wallet flows.

This white paper proposes a passwordless, crypto-based SSO solution that abstracts away blockchain complexity, blends seamlessly with standard web2 user experiences, and provides robust security by ensuring private keys never leave the user's device. Our platform employs WebAuthn passkeys (for biometric authentication), fallback cryptographic keypairs, and core web3 infrastructure—such as on-chain key anchoring, zero-knowledge proofs, or DID registries (e.g., via ZKSync)—while keeping these underlying operations invisible to end users unless they opt into advanced features. The result is a future-proof authentication solution that natively leverages blockchain security and user sovereignty without sacrificing simplicity.

2. Introduction

2.1 The Passwordless Imperative

Password Fatigue & Security Gaps
Users often reuse passwords across services, leading to large-scale data breaches. Enterprises invest heavily in identity management systems, but common vulnerabilities (phishing, credential stuffing) persist.

Rise of Passkeys & WebAuthn
Tech giants (Apple, Google, Microsoft) are rolling out device-based keypairs (passkeys) to replace passwords. This standard, governed by FIDO2 and WebAuthn, gives users a secure, local private key that is biometrically protected.

2.2 Web3 and Decentralized Identity: A Core Enabler

User-Owned Keys
Blockchain wallets illustrate how users can own cryptographic keys and digital assets. By integrating web3 at the core, we enable user sovereignty—removing the need for a central entity to hold or manage keys.

Beyond Optional
Many identity solutions treat web3 as an optional bolt-on. Here, blockchain-backed user ownership is baked into the platform from day one, ensuring each user's cryptographic identity can be anchored on an L2 (e.g., ZKSync) or a decentralized DID registry. For end users, it remains invisible or "optional" in the sense that no extra steps or wallet downloads are required—the complexity is abstracted away.

2.3 Our Vision

1. Frictionless, passwordless login with passkeys or fallback keypairs—no passwords, no confusion.
2. Non-custodial—user private keys remain in secure enclaves or local storage, removing centralized points of failure.
3. Enterprise-grade SSO—fully supports web2 standards (OIDC, SAML, on-prem deployments).
4. Web3 baked in—the entire system is designed around cryptographic, decentralized identity principles. L2-based zero-knowledge proofs, DID registries, or smart contract wallets are seamlessly integrated into the authentication flow. End users can remain unaware of the blockchain mechanics or opt into advanced features when needed.

3. Problem Statement

1. Centralized Identity Systems: Traditional solutions require trusting a single identity provider that stores all user credentials. A breach or misconfiguration at the IdP can compromise thousands of users.
2. Phishable Credentials: Passwords, OTPs, and even magic links can be intercepted or socially engineered.
3. Lack of Integrated Web3 Compatibility: While web3 can solve user-owned key problems, many identity solutions bolt it on as an afterthought. That leads to complex user experiences or incomplete coverage of decentralized identity benefits.
4. Poor Crypto UX: Existing web3 logins often require specialized wallets or seed phrases, scaring off mainstream users.

We aim to unify passwordless convenience with under-the-hood web3 security—ensuring every user truly owns their identity in a cryptographic sense, without being confronted by typical blockchain friction.

4. Proposed Solution

4.1 Core Principles

1. Passwordless By Default
   • All auth relies on cryptographic challenge–response—no password fields.
   • Eliminates password-based breaches and friction.
2. Web3 Native
   • Every user account is backed by a cryptographic key that can be anchored on a decentralized ledger (e.g., ZKSync).
   • End users do not need to understand tokens, wallets, or gas fees. The system provides gas abstraction or minimal on-chain interactions.
3. Non-Custodial, User-Owned
   • Private keys remain on the user's device—never leaving secure enclaves or local store.
   • This prevents a single service compromise from exposing user credentials.
4. Seamless Abstraction
   • For standard web2 apps, the experience looks just like a typical SSO: "Sign in with biometrics / passkey."
   • Under the hood, a zero-knowledge or on-chain approach ensures decentralized trust.
   • Developers can optionally tap into advanced features (e.g., DID-based credentials, zero-knowledge attribute proofs) without rewriting their apps.
5. Enterprise-Ready
   • Supports standard SSO protocols (OIDC, SAML).
   • Offers on-prem, hybrid, or cloud-based deployments.
   • Scalability, compliance, and advanced auditing features built in.

5. Technical Architecture

5.1 High-Level Overview

1. Client
   • Uses WebAuthn or locally generated keypairs for challenge–response.
   • Private keys never leave the device.
   • If using passkeys, device hardware enclaves store them.
2. Auth Service
   • Verifies signatures from client-provided challenges using known public keys.
   • Issues session tokens (JWT/OIDC) for standard SSO.
   • Writes to / reads from an L2 ledger (ZKSync) or a DID registry to anchor user identity data or handle zero-knowledge proofs.
3. Decentralized Ledger (Core)
   • Maintains an immutable record of user identity states and key references.
   • Gas and transaction fees are abstracted from the user (paid by the service or integrated via account abstraction).
   • Zero-knowledge modules allow advanced privacy or compliance features (e.g., selective disclosure of user attributes).

5.2 WebAuthn + On-Chain Integration

Registration Flow

1. User triggers navigator.credentials.create().
2. A passkey is generated—public key is returned to the Auth Service.
3. Auth Service writes a reference to ZKSync or a DID document (optional in MVP, but core to the architecture).
4. The user's identity can thus be cryptographically tied to an on-chain anchor.
5. No user sees "Crypto addresses" or "Gas fees."

Login Flow

1. navigator.credentials.get() prompts the user's biometric or PIN.
2. A signed challenge is verified by the Auth Service.
3. Optionally, the Auth Service can check or update a record on ZKSync (e.g., to confirm the key is still valid or to store a login event).
4. The user receives a standard OIDC token or session cookie for app access.

5.3 Key Fallback for Non-Passkey Devices

• Local Key Gen: If WebAuthn is not available, the user's browser generates an ECC/RSA pair.
• On-Chain Registration: If web3 is a requirement, a minimal transaction can store or update the user's public key in a registry contract or DID system—still abstracted from the user.
• Login: The client signs a challenge with the local private key; verification references the on-chain public key or a local DB copy.

5.4 Zero-Knowledge Proof Enhancements

• Selective Disclosure: The user can prove certain facts (e.g., "I'm over 18," "I have a valid enterprise credential") without revealing personal data.
• zkLogin / OAuth bridging: Tools like Sui's zkLogin or custom ZK circuits can let a user link a web2 account to a web3 key privately.
• Enterprise Use: Companies can issue cryptographic credentials to employees on a ledger; employees prove membership or role via zero-knowledge to third parties.

6. Security Considerations

1. No Central Private Key Storage
   • Eliminates the single biggest point of failure.
   • A server breach cannot yield mass user credential compromise.
2. On-Chain Integrity
   • Key references anchored to a decentralized ledger mitigate tampering by insiders or advanced attackers.
   • Zero-knowledge proofs ensure personal details never go public.
3. Gas & Account Abstraction
   • The platform pays or abstracts transaction fees, ensuring frictionless user flows.
   • If a user chooses advanced on-chain actions, the service can sponsor or partially offset fees.
4. Recovery & Multi-Device
   • Register multiple passkeys (e.g., phone, laptop).
   • Enterprise admins can re-verify employees if needed.
   • Social/contract-based recovery flows for advanced wallets.

7. Deployment & Infrastructure

7.1 Cloud SaaS

• Multi-tenant, serving many applications.
• Automatic ledger interactions behind the scenes.
• Global scaling and compliance certifications (SOC 2, GDPR).

7.2 On-Premise / Private Cloud

• Full node or private chain integration for highly regulated customers.
• Helm charts or container images for easy deployment behind corporate firewalls.

7.3 Hybrid Model

• Auth service in the cloud, while certain sensitive or compliance-heavy data on a private ledger.
• Minimizes overhead for organizations not ready to manage fully on-prem solutions.

8. Use Cases

1. Enterprise SSO with Future Web3 Integration
   • Replace passwords in a large corporation.
   • Employees hold keys recognized on a ledger, allowing optional expansions (e.g., verifiable credentials).
2. Web3 dApps
   • Users sign in with passkeys or local keys, automatically controlling an L2 wallet.
   • Freed from gas transactions or seed phrase management.
3. Consumer Platforms
   • Invisible blockchain usage.
   • Crypto-based identity for loyalty or membership tokens, or zero-knowledge age checks.

9. Roadmap

Phase 1: MVP

• Core Passkey Flow
• Fallback Keypairs
• Local DB Public Key Storage
• Basic OIDC Integration

Phase 2: Web3 Anchoring & ZK

• On-Chain Key Registration (ZKSync or other L2)
• Gas Abstraction
• Zero-Knowledge Proof Demos (e.g., attribute verification)

Phase 3: Advanced Enterprise & DID

• SAML
• On-Premise
• Fully Managed DID issuance & verifiable credentials
• Complex Recovery Flows (social recovery, multi-sig)

Phase 4+: Marketplaces & Partnerships

• Integration with KYC/AML vendors
• Expansion into regulated industries (healthcare, finance)
• Open standards collaboration (FIDO, W3C DID)

10. Business Model

1. B2B SaaS
   • Monthly Active User (MAU) pricing.
   • Free tier for developers.
2. On-Prem Licensing
   • Annual subscription + support.
   • Suited for regulated or large-scale enterprises.
3. Web3 Monetization
   • Potential transaction or bridging fees.
   • Premium features around zero-knowledge proofs, advanced DID management.
4. Open Core
   • A partial open-source approach fosters trust and adoption; enterprise add-ons generate revenue.

11. Competitive Advantage

1. Web3 as a Core, Not a Gimmick
   • The entire system is built around cryptographic identity and on-chain anchoring, fully abstracted from daily user tasks.
2. Frictionless UX
   • No "wallet install," no password prompts, no tokens to purchase for gas.
   • Familiar SSO flows with passkey biometrics.
3. Enterprise & Developer Focus
   • Supports standard protocols (OIDC, SAML).
   • Offers straightforward SDKs.
   • Easily deployed in multiple environments.
4. ZK Features for Privacy & Compliance
   • Allows advanced attributes or regulatory compliance checks without exposing user data.

12. Conclusion

This crypto-powered, passwordless SSO platform views web3 not as an optional afterthought, but as the foundational fabric. End users enjoy the simplicity of passkeys and instant logins, while behind the scenes, decentralized identity mechanics bolster security, integrity, and privacy. Enterprises can adopt standard SSO and compliance features, confident that the system's cryptographic bedrock eliminates single points of failure. Web3 dApps gain an immediate, user-friendly onboarding solution.

With incremental rollouts—from a minimal passkey-based MVP to robust zero-knowledge identity services—this platform can evolve into a universal authentication layer bridging modern web2 applications and the coming wave of decentralized identity.

Through hidden-but-powerful blockchain integration, we deliver frictionless user experiences alongside user-owned identity sovereignty.