Zcash × Nym

Using a centralized VPN

A VPN hides the client IP behind an exit gateway and nothing else: within a session requests stay grouped by connection state, and the operator sees both ends.

✅IP hidden · P1@L2❌Req-unlink · P2@L2❌Local net · P1@L3L❌Global net · P1@L3G✅Fast sync
VPN
ClientVPNlightwalletd
ClientVPNlightwalletd
VPN (no mixing)

Per-actor assessment & trade-offs

L2Compromised lightwalletd✅P1❌P2

Sees

  • VPN / exit gateway IP
  • All requests and contents
  • Resume heights across sessions

Can't see

  • Client IP

Residual / countermeasure

  • Within a session, requests remain grouped by connection state; across sessions the exit IP combined with resume heights re-identifies the wallet.
L3LLocal network observer

Sees

  • Activity fingerprint (no in-transit protection)
L3GGlobal network observer

Sees

  • Both ends — the relay operator is a single party that can function as a global observer

Pros

  • Fast

Cons / mitigations

  • Single operator sees both ends
  • Add timing + block-height obfuscation

Fit

  • Fast sync while hiding IP — but weak unlinkability and a single trusted operator

Latency model

Regional (40)Continental (120)Intercontinental (300)
VPN240 ms (2 hops)
Geographic propagation (speed-of-light)
Baseline hygiene applies here tooWhatever the transport, the wallet still owes the same Layer-2 discipline: randomize request times, obfuscate the start height, and never broadcast on reaching the tip.Full detail →

Content from the Nym × Zcash reference doc. Latency figures are an illustrative model (not measured).