The Risks of Using Wasabi Wallet

A thread on Wasabi Wallet after more digging/research:

First off, please do not connect my joining their Space last week or researching their protocol as lending *any* credence or support for their approach or wallet. I still do not recommend using it in any way.

— Seth For Privacy (@sethforprivacy) April 3, 2023

Digging into WabiSabi has revealed some core issues that should prevent you from considering using it. Note this list is not in any particular order.

1) Wasabi's funding and willing usage of chain surveillance companies puts your on-chain data at risk when you use them.

— Seth For Privacy (@sethforprivacy) April 3, 2023

This usage of CA could not only lead to harming your privacy directly, but could also easily be turned into a honeypot where "bad inputs" automatically get sent to mix with only Sybil inputs, providing 0 privacy but not showing that in your client.

Easy surveillance.

— Seth For Privacy (@sethforprivacy) April 3, 2023

2) WabiSabi as a protocol is only a tool for aggregating inputs where each input/output is blinded from the coordinator, and is not in any way a Coinjoin protocol - it is merely the input aggregation portion of one.

As such, the specifics of the WW2 protocol are unclear.

— Seth For Privacy (@sethforprivacy) April 3, 2023

3) There is currently *zero* way to verify the privacy provided by a given mixing round in WW2, and even Wasabi themselves don't seem to understand how their "anon score" metric works.

If you can't verify the privacy you get, you *should not trust it*.

— Seth For Privacy (@sethforprivacy) April 3, 2023

4) "Lonely whales" (i.e. those with larger amounts of Bitcoin) can often gain *zero* privacy in mixes and have 100% deterministic links between their inputs and outputs.

Have seen as little as 6 BTC gaining no privacy from mixing rounds.

— Seth For Privacy (@sethforprivacy) April 3, 2023

5) Due to the client + coordinator not learning amounts chosen by participants in rounds, you can never be sure that a mixing round provides you with any privacy, as it's always possible no one selects the same amounts as you, providing an anon set of 1 (your input/output).

— Seth For Privacy (@sethforprivacy) April 3, 2023

6) The usage "big TX = good privacy" in Wasabi marketing is BS, as the only thing that matters for privacy in a transaction is the potential outputs to match your inputs.

That is really only the outputs that share a denomination with your output, not all outputs in a TX.

— Seth For Privacy (@sethforprivacy) April 3, 2023

7) If the creators of this purported privacy tool don't know how to measure the privacy provided by their protocol, it should raise red flags for you.

Not knowing how your own protocol actually provides privacy opens up so many potential implementation flaws.

— Seth For Privacy (@sethforprivacy) April 3, 2023

8) There is a *long* history of tracing of Wasabi's previous implementation due to flaws in protocol and flaws in implementation, so we should be incredibly wary of trusting privacy claims until 100% proven over time.

— Seth For Privacy (@sethforprivacy) April 3, 2023

9) There remain *zero* post-mix spending tools in Wasabi, something that is absolutely vital to actually gaining privacy from Coinjoin's when spending Bitcoin. Even if the protocol was perfect this would lead to many privacy issues and "foot guns".

— Seth For Privacy (@sethforprivacy) April 3, 2023

This thread comes after spending many hours digging into the WabiSabi protocol, their documentation, and speaking with them at length.

I have no personal beef with Wasabi but try to remain open to learning from new approaches and wanted to give WabiSabi a fair shake.

— Seth For Privacy (@sethforprivacy) April 3, 2023

As a note to Thibaud and others I spoke with on the Space last week, that was not merely recon or similar, I genuinely wanted to learn and thought that would be a good place.

Unfortunately I didn't really get much mic time or many questions answered and it felt like marketing.

— Seth For Privacy (@sethforprivacy) April 3, 2023

I don't write this thread to incite more hateful rhetoric between "camps," but because I care about *your* privacy above all and do not want to accidentally push people to use a tool I don't deem sufficient for privacy in Bitcoin.

— Seth For Privacy (@sethforprivacy) April 3, 2023

Just as I love and recommend Monero widely while working on Bitcoin, I love and recommend @SamouraiWallet as a proven tool for privacy that I have used successfully over the years and seen proven time and again to work and provide solid privacy on-chain.

— Seth For Privacy (@sethforprivacy) April 3, 2023

If I saw Wasabi Wallet as a workable and useful privacy tool today without core issues I wouldn't hesitate to recommend it, as I'm not an anything maximalist or tied to any camps.

But that is not the case today, and I can't recommend anyone use Wasabi Wallet (still).

— Seth For Privacy (@sethforprivacy) April 3, 2023

I'm sure this will piss a lot of people off (I seem good at that recently 🙃) I want to always be sure that people know where I stand in relation to privacy tools, and that stance hasn't changed despite spending a good amount of time digging into Wasabi.

— Seth For Privacy (@sethforprivacy) April 3, 2023