Identity-First Secure Connectivity With No Open Inbound Ports

Atsign builds an identity-first connectivity layer for organizations that need people, applications, devices, services, and AI agents to reach one another without exposing anything to the public internet. The company is led by CEO Aparna Rayasam, previously at Akamai, Palo Alto Networks, and F5, and by co-founder and CTO Colin Constable, whose background spans British Telecom, Credit Suisse, and Juniper Networks. Stated buyers include CISOs, infrastructure operators, and engineering teams across healthcare technology, financial services, and critical infrastructure.

The technical model replaces network addressing with cryptographic identity. Each participant is issued an atSign backed by locally generated key pairs and a corresponding atServer that validates identity and stores only encrypted data it cannot decrypt. In the NoPorts product, a daemon on the target machine and the client both authenticate over the atProtocol, then dial outbound to a relay that bridges two rendezvous ports, so neither side ever opens an inbound listener. Session traffic uses an ephemeral AES-256 key the relay never holds.

Positioning rests on eliminating attack surface rather than filtering it: a service with no listening port cannot be scanned, enumerated, or brute-forced, which the company markets as a VPN and jump-host replacement for remote access, IoT fleets, CGNAT and Starlink links, and MCP servers. A companion tool, AI Architect, has teams model identities, authority, and data flows into a blueprint that feeds AI coding assistants. Core components are open source with OpenSSF scorecard coverage, and penetration test results are offered on request.