OpenSigner

Product Introduction

1. OpenSigner is an open-source, self-hostable key management stack designed to create and manage non-custodial wallets for blockchain networks like Ethereum and Solana. It enables developers to issue cryptographic keys to users without retaining custody, ensuring end-to-end control remains with the end-user. The platform supports integration with existing authentication systems and offers deployment flexibility via cloud hosting or private infrastructure.
2. The core value of OpenSigner lies in its ability to eliminate reliance on third-party custodians while maintaining enterprise-grade security for blockchain key management. It provides organizations with full control over their cryptographic infrastructure, reducing risks associated with vendor lock-in and centralized storage. By prioritizing self-hostability and modular design, OpenSigner empowers developers to build secure, compliant, and user-owned wallet solutions.

Main Features

1. OpenSigner uses decentralized key generation protocols to create Ethereum and Solana wallets programmatically, ensuring private keys are never exposed to external servers. Keys are split into shards using threshold cryptography, stored across hot (online) and cold (offline) storage components for enhanced security.
2. The platform offers plug-and-play compatibility with authentication providers like OAuth, SAML, or custom systems, enabling seamless integration into existing user onboarding workflows. Developers can embed wallet creation into apps via APIs or an iFrame module without modifying backend infrastructure.
3. OpenSigner’s architecture supports hybrid deployment models, allowing teams to run the stack in their own cloud environment (AWS, GCP, etc.) or use OpenSigner’s managed service. All components—authentication, hot storage, cold storage—are modular, enabling customization for compliance requirements like GDPR or SOC 2.

Problems Solved

1. OpenSigner addresses the critical security risk of centralized key storage by decentralizing control through non-custodial key sharding. Traditional custodial solutions expose organizations to single points of failure, while OpenSigner’s cryptographic splits ensure no single entity holds complete keys.
2. The product targets blockchain developers, fintech companies, and enterprises requiring regulatory-compliant wallet solutions without dependency on proprietary vendors. It is particularly relevant for exchanges, dApps, and institutions managing high-value digital assets.
3. Typical use cases include onboarding users with self-custodied wallets via email/SMS authentication, securing institutional funds with multi-party cold storage, and integrating non-custodial features into DeFi platforms without rebuilding key management infrastructure.

Unique Advantages

1. Unlike closed-source competitors like Fireblocks or Fortmatic, OpenSigner provides full code transparency, allowing audits and modifications to meet specific security or regulatory needs. Its self-hostable design eliminates recurring SaaS fees and data residency concerns.
2. The platform innovates with a hybrid storage model: hot storage handles frequent transactions via HSM-backed APIs, while cold storage uses air-gapped servers for long-term key shards. This balances accessibility with uncompromising security for high-risk operations.
3. OpenSigner’s competitive edge stems from its avoidance of vendor lock-in—users can migrate keys between cloud/on-premises setups or even fork the entire stack. Prebuilt Postman collections and authentication templates reduce integration time from months to days.

Frequently Asked Questions (FAQ)

1. How does OpenSigner ensure keys remain non-custodial? Keys are split into shards using threshold signatures (TSS) or multi-party computation (MPC), with shards distributed between user devices and the organization’s storage. No single party can reconstruct the full key without explicit user authorization.
2. Can OpenSigner integrate with our existing user database? Yes, the authentication service supports OIDC, SAML, and custom JWT flows, allowing direct mapping to your user directory. Key creation events can trigger webhooks to sync with internal systems.
3. What is the difference between hot and cold storage in OpenSigner? Hot storage manages frequently accessed key shards in hardened, encrypted memory for transaction signing, while cold storage uses offline servers with physical air-gapping for long-term shard archival. Both layers enforce multi-factor approval for shard retrieval.