A current article entitled “Breaking MimbleWimble’s privateness mannequin” printed by Ivan Bogatyy has been inflicting a stir because the writer claims of a “new assault” that ‘traces 96% of all (MimbleWimble) sender and recipient addresses in actual time’. The assault prices $60/week of AWS (Amazon Net Providers) one thing that leads Bogatyy to conculde that:

“Mimblewimble’s privateness is essentially flawed.” (and) “ought to not be thought-about a viable different to Zcash or Monero with regards to privateness.”

The issue is that no MimbleWimble (MW) developer has ever claimed the protocol was non-public or that it was on par with an asset reminiscent of Monero on this regard, as such Bogatyy’s article engages in a false equivalence fallacy. The considerations raised had been already identified to these engaged on the mission. David Burkett, a member of the Grin++ workforce who helps lead the Litecoin MW implementation, weighed in by way of twitter, to handle the scenario:

“Actually superior write-up, however none of that is “information”. I’m really stunned solely 96% was traceable. There are a selection of the way to assist break linkability in Grin, however none are applied and launched but. As I at all times say, don’t use Grin in the event you require privateness — it’s not there but.”

A counter article from Daniel Lehnberg, a Grin developer, was later printed to supply additional clarification and dispel the factual inaccuracies and sensationalised claims:

“This isn’t new to anybody on the Grin workforce or anybody who has studied the Mimblewimble protocol. Grin acknowledged the power to hyperlink outputs on chain in a Privateness Primer printed on its public wiki in November 2018, earlier than mainnet was launched. This drawback encompasses Ian Mier’s “Flashlight assault”, which we now have listed as considered one of our Open Analysis Issues.”
“TL;DR: Mimblewimble privateness is just not “essentially flawed”. The described “assault” on Mimblewimble/Grin is a misunderstanding of a identified limitation. Whereas the article supplies some attention-grabbing numbers on community evaluation, the outcomes offered don’t really represent an assault, nor do they again up the sensationalized claims made.”

Litecoin creator Charlie Lee adopted in a tweet of his personal stating:

“This limitation of MimbleWimble protocol is well-known. MW is principally Confidential Transactions with scaling advantages and slight unlinkability. To get a lot better privateness, you may nonetheless use CoinJoin earlier than broadcasting and CJ works very well with MW because of CT and aggregation.”

The primary attraction of MW and the rationale the Litecoin Core workforce want to implement help for it, has primarily been its skill to supply community fungibility, future scalability and ‘better’ (not full) privateness.

Fungibility is derived from the inclusion of confidential transactions (CT) whereby the worth despatched over the community is hidden but verifiable. This implies when interacting with different folks on the community they wont have the ability to look again and understand how a lot Litecoin you personal. Scalability alternatively comes from the massively pruneable nature of the protocol and the truth that, when paired with extension blocks, the Litecoin community could have a blocksize improve with out the necessity for a contentious onerous fork.

MW presents solely pseudo-privacy and that is what Bogatyy’s article discusses. By snapshotting transactions earlier than they endure the coin becoming a member of course of it’s nonetheless attainable to trace community participant interactions. Customers can privately coinjoin utilizing a trusted social gathering earlier than broadcasting, nonetheless, this introduces a 3rd social gathering who could then later promote that information on, so it’s removed from an excellent answer.

Coinjoins mixed with confidential transactions nonetheless, does present an satisfactory stage of privateness over the present scenario. The typical person doesn’t have the time, assets or know the best way to setup such a monitoring system. This doesn’t imply privateness is to not be pursued, for one, MW would not really use addresses, as a substitute worth is transferred by including one-time outputs to a transaction. In flip offering better privateness because it turns into inconceivable to re-use addresses.

One good take away is that it’s unlikely incumbent exchanges will delist Litecoin because of regulatory problem folks have raised and hopefully extra folks will start to know the character of MW. Full fungability continues to be a purpose to intention for going ahead and is somthing Lee awknowledges stating:

“There’s loads of work to be accomplished. Privateness and fungability will likely be an ongoing battle.”