hLink: A Scalable Linking Model for Decentralized Networks Keywords nthlink, decentralized networking, link abstraction, metadata routing, graph relations, scalability, interoperability Description NthLink is a conceptual model and set of practices for creating, managing, and traversing nth-order links in decentralized systems. It emphasizes lightweight link metadata, transitive relationships, and privacy-preserving discovery to enable scalable graph navigation across federated services. Content As distributed systems and decentralized applications proliferate, simple point-to-point links are no longer enough to represent the rich relationships between resources, identities, and services. NthLink is a linking model designed to express and manage nth-order relationships — links that capture not only direct connections but also transitive, contextual, and semantic relationships across federated networks. At its core, NthLink introduces a compact link abstraction: each link encapsulates a source, a target, a relation type, and a small set of optional metadata (weight, timestamp, provenance, and minimal access conditions). Unlike monolithic link registries, nthlink encourages local ownership of links while enabling controlled discovery through standardized metadata queries. This balances decentralization with the practical needs of discovery and routing. One of the principal benefits of nthlink is scalability. By limiting per-link metadata and delegating heavy computations to local nodes, networks can grow without centralized indexing bottlenecks. NthLink supports transitive queries — for example, "find resources two hops away with relation type ‘endorsed’ and weight above 0.7" — enabling applications to perform multi-hop discovery without fetching whole graphs. Cached path summaries and probabilistic filters (like Bloom filters) are recommended techniques to keep discovery lightweight. Interoperability is another key design goal. NthLink prescribes a small set of interoperable primitives for link exchange (announce, revoke, query) and a neutral serialization format that can be embedded in existing protocols (HTTP headers, activity streams, or compact JSON-LD snippets). This allows diverse systems — content platforms, identity providers, and peer-to-peer networks — to participate in a shared link ecosystem without adopting a new monolithic stack. Privacy and provenance are addressed by design: each link’s provenance field records the issuer and cryptographic signature, while access conditions can be expressed as capability tokens or pointers to authorization venues. Applications can therefore prefer links from trusted issuers or filter by provenance chains, reducing misinformation risks while preserving user control. Real-world use cases for nthlink include federated content recommendation, decentralized social graph traversal, supply-chain provenance tracking, and multi-party trust anchoring. For instance, in a federated news network, nthlink can represent endorsements, corrections, and citations across independent publishers, enabling consumers to navigate context-rich narratives without depending on a single indexer. Challenges remain: designing efficient multi-hop query semantics that resist spam, defining standard relation vocabularies, and ensuring lightweight cryptographic verification. However, with careful engineering, nthlink offers a pragmatic bridge between fully centralized link indexing and ad-hoc, brittle peer-to-peer references — empowering applications to navigate complex, federated information spaces with clarity and control.