Definition
A decentralized VPN replaces the traditional 'one company runs all the servers' model with a network of independent nodes — often ordinary people running software on a home computer or rented VPS — who provide bandwidth in exchange for cryptocurrency payments. Notable projects include Mysterium, Sentinel, Orchid, and Deeper Network. The architectural promise is that no single party can log all your traffic, no single jurisdiction can compel cooperation, and no single point of failure can take the whole service down.
Trade-Offs
Decentralization solves the 'trust one provider' problem but introduces new ones. Performance varies wildly because nodes are residential or budget-cloud rather than purpose-built infrastructure. Node operators are pseudonymous, so a malicious actor could run nodes specifically to log traffic — the model relies on the assumption that the network is large enough that any single observer sees only a small fraction. Some dVPNs use multi-hop routing similar to Tor to mitigate this, sacrificing more speed for more privacy.
Practical Maturity
As of the mid-2020s, dVPNs are interesting from a research and ideological standpoint but generally lag behind centralized providers in speed, reliability, and feature completeness. They are most useful when the threat model specifically requires distrusting any single VPN operator, or in jurisdictions where centralized VPNs are blocked at the IP level.