Grin Observer - GRN/BTC - Price Movement and Discussion

[Hueristic]

Just a heads up guys, it is not a good Idea to be Holding right now.

breaking-mimblewimble-privacy-model

Grin still affords a stronger privacy model than Bitcoin or other non-privacy coins, since amounts are safely encrypted. But Mimblewimble provides a strictly weaker privacy model than Zcash or Monero. This makes it insufficient for many real-world privacy use cases.

https://medium.com/dragonfly-research/breaking-mimblewimble-privacy-model-84bcd67bfe52


This is not FUD, just a heads up. I'm sure the Devs will address the issue if its possible.

I havn't spent any time in looking into this but wanted to give you guys a heads up asap.
Thanks to cAPSlOcK for pointing this out.

This is the actual article by the researcher:

https://medium.com/dragonfly-research/breaking-mimblewimble-privacy-model-84bcd67bfe52

Just so you all know and don't get blind sided.

Added:

Here is the rebuttable Dev response.

https://medium.com/p/8063371839b9/responses/show

If  I sold then I'm buying back.

[1715623499]

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[RivAngE]

Did it drop because people started hypothesizing on a possible tractability issue? I see a good opportunity to buy this dip!


First of all, it's easy to fix: BEAM has added dummy transactions of 0 value when a "block" has too few transactions, making this "attack" impossible. GRIN could implement it as well if needed, though I'm worried about how much larger the blockchain will get with dummy transactions.

Secondly, we're just talking about a user who has purchased GRIN from a KYC service and whom there's a reason to trace (for example because he used them in an illegal trade).
So I wonder... why would a criminal use a KYC service and give their real IDs (like it'd be hard to trick these systems)? If they did not give their real personal information, then the most this hard-to-achieve-attack would reveal would be where did the criminal bought their coins.

[bbc.reporter]

Just a heads up guys, it is not a good Idea to be Holding right now.

breaking-mimblewimble-privacy-model

Grin still affords a stronger privacy model than Bitcoin or other non-privacy coins, since amounts are safely encrypted. But Mimblewimble provides a strictly weaker privacy model than Zcash or Monero. This makes it insufficient for many real-world privacy use cases.

https://medium.com/dragonfly-research/breaking-mimblewimble-privacy-model-84bcd67bfe52


This is not FUD, just a heads up. I'm sure the Devs will address the issue if its possible.

I havn't spent any time in looking into this but wanted to give you guys a heads up asap.
Thanks to cAPSlOcK for pointing this out.

This is the actual article by the researcher:

https://medium.com/dragonfly-research/breaking-mimblewimble-privacy-model-84bcd67bfe52

Just so you all know and don't get blind sided.

Added:

Here is the rebuttable Dev response.

https://medium.com/p/8063371839b9/responses/show

If  I sold then I'm buying back.

However, it is fud. Here is a better article to read on why it is fud.

https://medium.com/grin-mimblewimble/factual-inaccuracies-of-breaking-mimblewimbles-privacy-model-8063371839b9

The Dragonfly research fellow might have gotten very excited on his research which was already well known from the beginning.

[suchmoon]

The Dragonfly research fellow might have gotten very excited on his research which was already well known from the beginning.

It's amazing how well clickbait works. I'm quite illiterate about Grin but I read a bit about it back in January when it launched and I remember the linkability issue being mentioned in a few places in the documentation. Even without that background knowledge you'd think people would be at least a little bit suspicious and curious if the sky is really falling. But no. Even though a simple google search would show that this was known pretty much since MW was "invented" in 2016.

The linkability of UTXOs (there are no addresses in Grin so "I was able to uncover the exact addresses of senders and recipients" is false right off the bat) doesn't disclose as much as the "researcher" seems to imply and there are ideas how to obfuscate the UTXOs even more. But that's not as exciting as "privacy coin broken".

[bbc.reporter]

@suchmoon. Also, Zcash and Monero were mentioned and compared as better for privacy. Which is true, however, this exposes his bias and what he might be holding hehehe. No one from the Grin development team claimed better privacy.

Also, writing it after a 2011 miner donated 50 bitcoins from a coinbase transaction hehe.

[Hueristic]

Just a heads up guys, it is not a good Idea to be Holding right now.

breaking-mimblewimble-privacy-model

Grin still affords a stronger privacy model than Bitcoin or other non-privacy coins, since amounts are safely encrypted. But Mimblewimble provides a strictly weaker privacy model than Zcash or Monero. This makes it insufficient for many real-world privacy use cases.

https://medium.com/dragonfly-research/breaking-mimblewimble-privacy-model-84bcd67bfe52


This is not FUD, just a heads up. I'm sure the Devs will address the issue if its possible.

I havn't spent any time in looking into this but wanted to give you guys a heads up asap.
Thanks to cAPSlOcK for pointing this out.

This is the actual article by the researcher:

https://medium.com/dragonfly-research/breaking-mimblewimble-privacy-model-84bcd67bfe52

Just so you all know and don't get blind sided.

Added:

Here is the rebuttable Dev response.

https://medium.com/p/8063371839b9/responses/show

If  I sold then I'm buying back.

However, it is fud. Here is a better article to read on why it is fud.

https://medium.com/grin-mimblewimble/factual-inaccuracies-of-breaking-mimblewimbles-privacy-model-8063371839b9

The Dragonfly research fellow might have gotten very excited on his research which was already well known from the beginning.

I supplied the responses to the article link rather than the link you supplied, my bad.

You can click the article you linked in the link I supplied here.

Here is the rebuttable Dev response.

https://medium.com/p/8063371839b9/responses/show

If  I sold then I'm buying back.

It's not really fuD (as it is true), if you read the Devs responses they even conform it. I personally had forgotten all about this as it was discussed pre launch and it is a known issue in the grin Lab list. It is a rehash of an old known attack vector.

Basically a full node can log all this information from the genesis and have all the connecting information. There is nothing that can be done about that currently.


The Fud is the distorted way it has been presented and the hyperbole that accompanies the information as if it is a new revelation. I wish my memory was better as I should have noticed that when I was reading the article initially.

[bbc.reporter]

waiting for $0.50 hehehe.

Waiting for $0.50, that might never really happen.  Maybe better take few prices and buy part of it then. Like 1/3 at $1, 1/3 at $0.5 and 1/3 at $0.25.

I did not try to argue with this because the pump made it appear that you might be right. We always forget the certain dump, however. $0.50 is back on the schedule for December hehehe.

[Globb0]

It was about 40 pages back we discussed that fact someone can be logging all transactions.

[Hueristic]

It was about 40 pages back we discussed that fact someone can be logging all transactions.

You know my memory doesn't go back 40 pages!!!

I'm lucky if I remember what I posted yesterday!

[bbc.reporter]

@Globb0. That was not the issue. Was something broken in Grin similar to what the Dragonfly researcher was telling everyone? It was clickbait.

[Hueristic]

@Globb0. That was not the issue. Was something broken in Grin similar to what the Dragonfly researcher was telling everyone? It was clickbait.

The hyperbole about the "known issue" is the clickbait, not whether there is an issue or not. The issue has always been known and they are working on it.

This might shed some light on the discussion, direct from Grin dev David Burkett.
https://mobile.twitter.com/DavidBurkett38/status/1196447147929018368

Really awesome write-up, but none of this is "news". I'm actually surprised only 96% was traceable. There are a number of ways to help break linkability in Grin, but none are implemented and released yet. As I always say, don't use Grin if you require privacy - it's not there yet

Now is a great time to remind everyone we're looking for cryptographers, academics, or just generally smart people to tackle this problem. Write up a proposal and apply for funding!

I've never personally marketed grin as a privacy coin. It certainly will be someday soon, but I always make it a point to shutdown outlandish privacy claims. Currently it just has private amounts. Unlinkability improvements are definitely in progress though.

Daniel Lehnberg Grin Dev
https://medium.com/grin-mimblewimble/factual-inaccuracies-of-breaking-mimblewimbles-privacy-model-8063371839b9

The “attack” that the author claims to have made is the well-documented and discussed transaction graph input-output-linkability problem. This is not new to anyone on the Grin team or anyone who has studied the Mimblewimble protocol. Grin acknowledged the ability to link outputs on chain in a Privacy Primer published on its public wiki in November 2018, before mainnet was launched. This problem encompasses Ian Mier’s “Flashlight attack”, which we have listed as one of our Open Research Problems.

Grin Open research problem list.

https://grin.mw/open-research-problems

Number 7:

    Get Started
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    General Fund
    Research
    GitHub

Open Research Problems

This document summarizes several open research problems related to Grin.
Feel free to join us on Gitter to discuss them. Funding available.
Table of Contents
Number    Name
1    BLS Signatures
2    Accumulator
3    Kernel Aggregation
4    Scriptless Scripts
5    FlyClient
6    Asynchronous Transaction Building
7    Reducing Linkability of Outputs On Chain
8    Erlay Transaction Relaying
9    Payment Channel Hubs
10    Research on ZKPs Recent Advances
1. BLS Signatures
Description

Introduced in 2001 by Boneh, Lynn and Shacham, BLS signatures introduces non-interactive kernel aggregation and potentially simpler multisignature schemes.

While it is not for certain that such signatures are well suited for Grin it is still interesting to explore this design.
Relevant Papers

    D. Boneh, B. Lynn, and H. Shacham. Short signatures from the weil pairing. In Proceedings of the 7th International Conference on the Theory and Application of Cryptology and Information Security: Advances in Cryptology, ASIACRYPT '01, pages 514–532, Berlin, Heidelberg, 2001. Springer-Verlag.
    https://www.iacr.org/archive/asiacrypt2001/22480516.pdf

    D. Boneh, M. Drijvers, and G. Neven. Compact multi-signatures for smaller blockchains. Cryptology ePrint Archive, Report 2018/483, 2018.
    https://eprint.iacr.org/2018/483

Other resources

    BLS Signatures for Busy People

Github Issue

    https://github.com/mimblewimble/grin/issues/2504

2. Accumulator
Description

In Grin, kernels, outputs and range proofs are stored in a type of accumulator called a Merkle Mountain Range. While efficient, there have been several improvements to this kind of data structure, for example RSA Accumulators.
The goal of this research problem is to identify whether or not Grin can leverage more advanced or faster cryptographic accumulators.
Relevant Papers

    D. Boneh, B. Bünz, and B. Fisch. Batching techniques for accumulators with applications to IOPs and stateless blockchains. Cryptology ePrint Archive. 2018 https://eprint.iacr.org/2018/1188.pdf

3. Kernel Aggregation
Description

Grin blockchain implements the mimblewimble protocol. This design allows the blockchain to be massively prunable. However, while inputs/outputs can be thrown away once spent, there is another piece of data called the kernel that must stay. For each transaction a kernel is created, this piece of information cannot currently be aggregated or discarded as it is needed to verify the current chain state.

The goal of this research problem is to identify potential ways to aggregate transaction kernels and/or possibly discard them if not needed.

One potential construct is BLS signature. Introduced in 2001 by Boneh, Lynn and Shacham, BLS signatures introduce non-interactive kernel aggregation and potentially simpler multisignature schemes. While it is not for certain that such signatures are well suited for Grin it is still interesting to explore this design.
Relevant Papers

    D. Boneh, B. Lynn, and H. Shacham. Short signatures from the weil pairing. In Proceedings of the 7th International Conference on the Theory and Application of Cryptology and Information Security: Advances in Cryptology, ASIACRYPT '01, pages 514–532, Berlin, Heidelberg, 2001. Springer-Verlag.
    https://www.iacr.org/archive/asiacrypt2001/22480516.pdf

    D. Boneh, M. Drijvers, and G. Neven. Compact multi-signatures for smaller blockchains. Cryptology ePrint Archive, Report 2018/483, 2018.
    https://eprint.iacr.org/2018/483

Github Issue

    https://github.com/mimblewimble/grin/issues/2504

4. Scriptless Scripts
Description

Mimblewimble does not support any kind of script. In 2017, Andrew Poelstra introduced a way to add smart contracts ability to this type of blockchain: scriptless scripts.

While a significant research effort has been done on the subject there are very few concrete implementations of such cryptographic structure.

The goal of this research problems is to investigate scriptless scripts in Grin and potentially implement basic contracts features on a second layer.
Relevant Presentations

    Scriptless Scripts by Andrew Poelstra (2017)
    Scriptless Scripts with Mimblewimble (Grincon US)

5. FlyClient
Description

"To validate transactions, cryptocurrencies such as Bitcoin and Ethereum require nodes to verify that a blockchain is valid. This entails downloading and verifying all blocks, taking hours and requiring gigabytes of bandwidth and storage. Hence, clients with limited resources cannot verify transactions independently without trusting full nodes.[…] FlyClient is a novel transaction verification light client for chains of variable difficulty. FlyClient is efficient both asymptotically and practically and requires downloading only a logarithmic number of block headers while storing only a single block header between executions."

The goal of this research problems is to investigate/implement the necessaries prerequisites for the introduction of a FlyClient in Grin.
Relevant Papers

    B. Bünz, L. Kiffer, L. Luu, and M. Zamani. Flyclient: Super-light clients for cryptocurrencies. IACR Cryptology ePrint Archive, 2019:226, 2019. https://eprint.iacr.org/2019/226.pdf

Github Issue

    #1555

6. Asynchronous transaction building
Description

One of the trade-offs of the Mimblewimble type blockchain is that it requires a round trip between the payer and payee to construct a valid transaction. Meaning that the sender and receiver must be online to transact.

Several research attempts have been made in that direction. For example, relying on federated relays or Beam shared bulletin board system.

The goal is this research problem is to investigate and develop an asynchronous, robust, and privacy preserving method of building Grin transactions.
Github Resources

    Grin Draft RFC - Asynchronous Transacting via Relays

7. Reducing Linkability of Outputs On Chain
Description

Mimblewimble/Grin leverage confidential transactions to hide the identity of the sender and recipients. As such, there are no public amounts or addresses.

However, it is possible for someone listening on the network to build a transaction graph and possibly clustering entities together.

Techniques like Dandelion++ mitigate this issue but are insufficient for a privacy coin.

The goal of this research is to investigate ways to obfuscate the Grin transaction and implement such design.

[estenity]

remedy to be found soon ?
https://cointelegraph.com/news/litecoin-funded-grin-developer-challenges-mimblewimbles-privacy-issue

[Hueristic]

remedy to be found soon ?
https://cointelegraph.com/news/litecoin-funded-grin-developer-challenges-mimblewimbles-privacy-issue

Its great to see LTC funding development but I am hesitant to believe this is a solution.

“The Achilles heel of mimblewimble privacy though, has always been that transactions are broadcast before they’ve had a chance to be joined with other transactions. That means nodes monitoring the network can see the original input-to-output links of most transactions. Sending a transaction directly to a CoinJoin server before broadcasting is one of many different techniques we can use to combat that.”

This solution will add centralization which will add additional attack vectors. Now maybe if rather than sending to a central server all the nodes participate then that would add a large enough set but I have no clue what that would do to other protocol constraints.

Also Tari has been working with the MW protocol so there should be a solution within a year or two, actually perfect timing for when I have been waiting to buy in. weird how that worked out, i guess dyor really works.

https://www.tari.com/2019/02/11/tari-protocol-discussion-21.html
https://tlu.tarilabs.com/protocols/grin-beam-comparison/MainReport.html

[Febo]

LTC will use mimblewimble as a side chain. When we talk about privacy, real privacy can be made only on protocol level and not on second layers. Andreas Antonopoulos loves to preach about that. Not hard to find his content about it.

[bbc.reporter]

Grin $1.00 is strong! I will give it 6 months beginning on January, 2020 to dump on $0.50. However, if it remains strong, it might be the time to begin buying hehehe.

[Cryptotourist]

Grin $1.00 is strong! I will give it 6 months beginning on January, 2020 to dump on $0.50. However, if it remains strong, it might be the time to begin buying hehehe.

Finally!

[Globb0]

Soon (TM)

[bbc.reporter]

Grin $1.00 is strong! I will give it 6 months beginning on January, 2020 to dump on $0.50. However, if it remains strong, it might be the time to begin buying hehehe.

Finally!

Finally what? I said 6 months to see if $1.00 holds strong. That would be a long enough time for miners to tolerate before they begin dumping again hehehe.

[Hueristic]

Soon (TM)

HEY, this shit trademarked!

Grin $1.00 is strong! I will give it 6 months beginning on January, 2020 to dump on $0.50. However, if it remains strong, it might be the time to begin buying hehehe.

Finally!

Finally what? I said 6 months to see if $1.00 holds strong. That would be a long enough time for miners to tolerate before they begin dumping again hehehe.

Another year, sorry.

[Cryptotourist]

Finally what?

I can read what you said. Finally a positive-optimistic position.

#

Another year, sorry.

Pfff, still love ya - no fucking homo.