mixFetch / mixWS (WASM + TypeScript)

A drop-in fetch / WebSocket replacement — the only in-browser option. Routes over the 5-hop mixnet. Not for block syncs or short-timeout requests.

Runtime: TypeScript + WASM — WebView and web walletsMixnet (5-hop)Speed: Slow

Mixnet (5-hop)

ClientEntry GWMixExit GWlightwalletd

Mixnet (5-hop) (mixing delays)

Latency model

Geographic delay / hop120 ms

Regional (40)Continental (120)Intercontinental (300)

Mixing delay / layer50 ms

Mixnet (5-hop)1.6 s (6 hops, 3 mix layers)

Geographic propagation (speed-of-light)Per-hop mixing delayReliable-channel ACK (return, geographic only)

What to send over it

Transaction broadcasts
Small requests

Notes

mixFetch replaces fetch; mixWS covers WebSocket interfaces
Do not send block syncs, heavy traffic, or time-critical (short-timeout) requests
Slow — it is a mixnet over 5 hops globally

Per-actor assessment (inherited)

The same four threat actors apply. This architecture inherits the assessment of the configuration it implements: Mixnet · single IPR. Layer-2 baseline hygiene remains the wallet’s responsibility.

L2Compromised lightwalletd✅P1❌P2

Sees

Exit gateway / IPR IP
All requests and contents

Can't see

Client IP

Residual / countermeasure

The wallet's TCP connection to lightwalletd is an ordinary end-to-end connection arriving from the exit's IP. Per-packet unlinkability in transit does not translate into request unlinkability at the destination.
With a fixed IPR, P2 behaves exactly like the dVPN single-exit case — rotate the IPR per request to restore it (see the rotating-IPR scenario).

L3LLocal network observer✅P1

Sees

Constant-size packets at a Poisson rate with cover traffic
That the client uses the Nym mixnet

Can't see

Reliable destination, volume or activity

L3GGlobal network observer◐P1

Sees

Per-packet timing (hampered by mixing delays and cover traffic)

Residual / countermeasure

The extent to which bulk transfers of many packets can be correlated over time is an open question. The mixnet is strongest for small, independent messages and weakest for bulk sync — one reason bulk sync does not belong on the mixnet (the other is throughput).

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 →