August 8, 2025 7 min to read

Integrating the Handshake Protocol with Nostr: A Technical Overview

Integrating the Handshake Protocol with Nostr: A Technical Overview

Introduction

Nostr [1] (Notes and Other Stuff Transmitted by Relays) is a decentralized protocol designed for sending, receiving, and broadcasting content without relying on central servers. While Nostr successfully achieves decentralized communication, the protocol faces challenges regarding identity management, spoofing attacks, and scaling with the growing number of clients and relays.

The Handshake Protocol [2], a decentralized, permissionless naming protocol compatible with the Domain Name System (DNS), addresses a core internet infrastructure problem: the reliance on centralized entities for domain name resolution and identity verification. This technical document explores how Nostr could benefit from leveraging the Handshake protocol to enhance security, privacy, and scalability while mitigating issues such as sybil attacks and identity spoofing.

Overview of Nostr

Nostr operates on the principle of relays broadcasting messages and events. These messages are digitally signed by the users, ensuring integrity and non-repudiation. The network is open, where any user can act as a relay or participant.

Key Components of Nostr

• Clients: End-user applications that publish and receive events from relays.
• Relays: Intermediaries that store and broadcast events for connected clients.
• Events: Core data structures in Nostr, containing messages, signatures, and metadata.
• Public-Private Keypairs: User identities are represented by cryptographic keypairs.

Existing Challenges in Nostr

• Identity Management: Users are identified by public keys, which makes human-readable identities cumbersome.
• Sybil Attacks: Given the ease of generating keypairs, malicious users can flood the network with fake identities.
• Man-in-the-Middle (MitM) Attacks: Without robust identity verification mechanisms, relays could be compromised, leading to potential MitM attacks.

Overview of the Handshake Protocol

Handshake is a decentralized naming protocol that eliminates the need for a centralized Certificate Authority (CA) by using blockchain technology to provide a trustless DNS and name verification system. Each top-level domain (TLD) is secured through cryptographic proofs stored on the Handshake blockchain, allowing participants to securely own and manage domain names.

Handshake’s Cryptographic Foundation

Handshake uses Proof-of-Work (PoW) to maintain its blockchain. The consensus mechanism ensures that TLD ownership is cryptographically secured and resistant to tampering. Names are registered, managed, and transferred via Handshake, with every operation signed and verified via DNSSEC (Domain Name System Security Extensions).

Decentralized Domain Naming System

Unlike traditional DNS, Handshake does not rely on centralized authorities like ICANN. Instead, it replaces the root zone file with a decentralized, cryptographically verifiable alternative, ensuring tamper-proof name resolution.

Technical Synergy Between Nostr and Handshake

Enhancing Identity Management and Verification

Nostr users could register Handshake domain names and map them to their public keys. This mapping allows users to replace cumbersome public key representations with human-readable, secure domain names. Handshake’s decentralized nature prevents any central authority from seizing or revoking these domain names, ensuring long-term identity ownership.

1. Mechanism:
   • Users register a domain (e.g., alice.nostr) on Handshake.
   • The domain record contains the user’s Nostr public key.
   • Nostr clients can resolve these domain names via Handshake to retrieve and verify the associated public key.
2. Advantage:
   • Users no longer need to share long public key strings.
   • Domain-based identities are more resistant to spoofing and MitM attacks, as the DNSSEC-backed domain resolution ensures authenticity.

Domain-Based Communication Layers

Handshake domains can serve as a communication layer for identifying trusted relays. Nostr users could associate relays with their domain names, allowing clients to filter and connect only to trusted, verifiable relays.

• Mechanism: A relay could advertise itself under a Handshake domain, and clients could resolve this domain to verify the relay’s authenticity before exchanging events.
• Benefit: Prevents malicious or unauthorized relays from intercepting or tampering with user events by ensuring the relay’s identity is verifiable.

Mitigating Sybil and Spoofing Attacks

By associating each Nostr identity with a unique Handshake domain, the protocol could mitigate Sybil attacks. While generating new keypairs is trivial, registering multiple Handshake domains requires a financial commitment, thus reducing the incentive for attackers to flood the network with fake identities.

• Mechanism: Nostr relays could prioritize users whose identities are bound to Handshake domains, ensuring that the network is primarily composed of authenticated entities.

Naming Resolution Efficiency and Privacy

Handshake supports DNS-over-HTTPS (DoH) and DNS-over-TLS (DoT), enabling privacy-preserving name resolution. Nostr clients and relays could leverage these encrypted DNS mechanisms to resolve identities and relay addresses without exposing DNS queries to intermediaries.

Implementation Considerations

Integration of Handshake DNS into Nostr Clients

Nostr clients would need to implement support for querying Handshake domains. This can be achieved through libraries like hnsd [3], which enables DNS queries over Handshake. Clients can resolve usernames to public keys or relay addresses via this integration.

• API Integration: Clients query Handshake domains through a lightweight API, fetching user identities and their associated public keys.

Name Resolution Middleware for Nostr Relays

Relays can act as middleware, resolving Handshake domains before accepting connections from clients. Relays would verify user and relay identities by checking the cryptographic validity of the DNS records.

• Middleware Module: Implement a module that fetches Handshake DNS entries and validates them before allowing communication.

Key Exchange and Cryptographic Binding

Public keys registered on Handshake domains must be securely bound to their associated domain names using DNSSEC. This ensures that the domain holder is indeed the owner of the corresponding public key, preventing identity spoofing.

• Key Exchange: Handshake domains would publish a TXT record containing the Nostr public key, signed via DNSSEC to ensure authenticity.

Security Implications

Strengthening Identity Attestation with DNSSEC

Handshake’s native support for DNSSEC allows cryptographic attestation of domain ownership, ensuring that Nostr identities mapped to Handshake domains are authentic and verifiable.

• DNSSEC Benefits: Prevents unauthorized changes to domain-public key mappings, which could otherwise lead to identity hijacking.

Reducing Reliance on Third-Party CAs and Centralized Trust Models

By leveraging Handshake, Nostr would no longer need to rely on centralized CAs for identity verification. This reduces single points of failure and enhances the overall trustworthiness of identity management in the protocol.

Scalability and Performance Considerations

DNS Query Load Distribution

Handshake DNS queries, particularly over DoH/DoT, may add latency to name resolution in large-scale Nostr networks. Relays and clients need efficient caching mechanisms to minimize query loads while maintaining privacy and accuracy.

Performance Impact of DNS-over-Handshake (DoH) for Nostr Networks

Nostr relays and clients could leverage DoH to encrypt DNS queries while maintaining privacy. Handshake’s blockchain-based infrastructure ensures decentralized load distribution across nodes, enhancing scalability.

Potential Challenges and Limitations

Handshake DNS Propagation Delays

Handshake DNS changes may experience propagation delays across the network, potentially causing temporary inconsistencies in Nostr identity resolution.

Security Assumptions and Trust Models

While Handshake improves decentralization, it introduces new trust models around blockchain integrity and consensus mechanisms, which must be considered when integrating with Nostr.

Nostr Event Signatures and Handshake

Binding Nostr event signatures to Handshake domain records requires careful consideration to avoid mismatches between user identities and their associated domains.

Conclusion

Integrating the Handshake protocol into Nostr presents a robust solution for improving identity management, security, and scalability. By leveraging Handshake’s decentralized, cryptographically secure naming system, Nostr can mitigate common attacks while enhancing user privacy and trust in the network. Despite challenges such as DNS propagation delays and performance trade-offs, the synergy between these two protocols offers significant potential for the future of decentralized communication.

References

[1] Nostr Protocol Documentation
[2] Handshake Website
[3] Handshake Dev Documentation