Skip to content

WoSP and AMTD

What is WoSP?

WoSP (Workload Security Proxy) is an Envoy WASM filter that runs as a sidecar container (xtra-wasm) in every blueprint pod. It intercepts all inter-pod traffic and handles authentication and encryption automatically. Engineers configure it via secrets in 02-secrets.yaml; after that, it operates without intervention.

From your application's perspective, WoSP is invisible. Your app.py sends messages to localhost:<egress_port>; WoSP intercepts them, applies Zero Trust identity verification, encrypts the payload, and forwards to the destination pod. Inbound messages are decrypted and verified by WoSP before your app ever sees them.

What is AMTD?

AMTD (Automated Moving Target Defense) is the key rotation mechanism WoSP uses to prevent credential theft. Every 5–30 seconds, WoSP generates a new workload identity and invalidates the previous one. An intercepted credential becomes worthless within seconds — before an attacker can make use of it.

This is distinct from traditional certificate rotation, which typically happens on a schedule of days or months. AMTD operates on a sub-minute cycle, making the attack window practically zero.

Two WoSP modes

Mode Technical Name Key Rotation Scope Best For
Armored Tunnel xtra4 Per TCP session WebSocket, gRPC, persistent connections
Armored Car xtra7 Per HTTP request REST APIs, external-facing gateways

The mode is set at composition time and is reflected in the blueprint's CHIPS_ALGORITHM credential. You do not configure it directly — the blueprint manifests contain the complete WoSP configuration for the chosen mode.

Credentials WoSP needs

Three credentials are required for WoSP to initialize:

Credential Purpose
HOPR_LICENSE Validates the customer's license against the Hopr service
HOPR_KEY The workload's base identity key used for AMTD rotation
CHIPS_ALGORITHM Specifies the WoSP operating mode (xtra4 or xtra7)

A fourth credential, HOPR_API_TOKEN, is used for runtime API calls during AMTD rotation. All four are injected into 02-secrets.yaml at delivery time.

Tip

You do not configure WoSP directly. The blueprint manifests contain the complete WoSP configuration. Your job is to fill in the credentials and deploy.