[vlugorilla]

A 6 re-org does not mean a '51% attack' was successful. In that case, we'd see unbounded-depth re-orgs/no blocks mined by any other mining pool (assuming the adversary censors other mining pools, as this one does).

It does mean an adversary with a high amount of hash got lucky. I noted there's a discrepancy between their claimed network hashrate and pools' claimed network hash rate.

They may not be including their own hash rate in the network's, in which case they'd need to exceed it. Having 51% would only be 34% of total.

They're an unreliable narrator and I wouldn't trust any data from them. There's insufficient evidence to claim they have 51% of the network's hash power.

(https://nitter.net/kayabaNerve/with_replies)

[vlugorilla]

Qubic never actually hit 51% btw. Don't fall for it.

However they do have a large enough hashrate to perform multi-block re-orgs with their selfish mining strategy.

They disabled API hashrate reporting so that they could lie about it.

Keep mining and ignore the noise.

(https://nitter.net/tuxpizza/status/1955191610410401816#m)

[reorder9695]

I am not that well versed in crypto. I understand the concept of a blockchain and what an n block reorg is, but what is the downside of a reorg? Like who can profit financially and why?

[johnpaulkiser]

You get all the money from the block rewards for those blocks if you reorg other miners blocks out.

[cyanydeez]

America would be screwed if owning 51% of its value meant you could rewrite ownership.

*gestures wildly*

[01HNNWZ0MV43FF]

Good thing you need 30 percent, a larger number

[leokennis]

Didn't know ChatGPT was on HN

[red-iron-pine]

GPT has been shaping conversations on HN, directly or indirectly, since GPT-1 mate.

Reasonably creditable studies put 30-40% of social media having some sort of AI or automation. This is just the low hanging fruit.

[mvdtnz]

What's a "6 re-org"?

[acjohnson55]

I'm a little rusty with the terminology, but in a blockchain, the canonical current block is the one that has the greatest amount of proof of work (I think they call this the heaviest chain). Typically, each new block is the descendant of the most recent block. But it is possible to create a heavier chain from an earlier block. This invalidates any transactions on what was previously known to be the heaviest chain, and is called a reorg.

The farther back, the less likely a reorg is, so to have a reorg that invalidates is blocks is extremely unusual.

If one entity has a majority of the hash power, they gain the ability to try to force reorgs with a likelihood that increases with their advantage in hash power.

I typed all this before realizing I could have recommend you ask an LLM, and it probably would have given you a better answer.

[creatonez]

> I typed all this before realizing I could have recommend you ask an LLM, and it probably would have given you a better answer.

Please don't. This would be useless spam, and is completely rude. Do we tell people to "Just google it?" here?

[acjohnson55]

It's different in that there's no need to go hunting through search results. This is what Claude responded when I just asked it: https://claude.ai/share/684fa294-ee35-4044-8344-99e1ceb2e643

I don't think that's spam at all, and I don't think I did anything special in my prompt that someone with less background knowledge could have done.

[tromp]

User skarz did indeed ask an LLM, which got [flagged] since the LLM gave a distinctly worse answer. Expand the [9 more] below to see it.

[jmholla]

This was a great answer. I'm glad you spent the time on it. Though I am curious what the 6 indicates.

[ningen_000]

Six blocks

[NooneAtAll3]

who are "they" you're talking about?

[vlugorilla]

"They" refers to Qubic (by Sergey Ivancheglo), a blockchain network that uses a "Useful Proof-of-Work" system, so it is not built for traditional cryptocurrency mining that solves arbitrary puzzles. Instead, it uses the collective processing power of its miners to train an AI. Qubic's AI-training work is performed by CPUs, same as used by RandomX (Monero's mining algo).

Qubic was able to orchestrate its network of miners to temporarily halt their AI-related tasks and redirect their collective CPU power to mine on the Monero network instead.

Also, Qubic has implemented an economic strategy that involves selling the Monero it mines for a stablecoin like USDT and then using those funds to benefit its own ecosystem and attract more miners, and renting hardware to gain more hash power. The proceeds from the sale of XMR are used to buy Qubic's native token (QUBIC) from exchanges. These purchased tokens are then "burned" or permanently removed from circulation.

[sidewndr46]

This seems oddly similar to the whole IRON/TITAN thing years back, but with extra steps.

[greazy]

What's their objective?

[treyd]

My guess would be to turn the crank of a ponzi scheme until it falls off.

However,

> Qubic's AI-training work is performed by CPUs, same as used by RandomX (Monero's mining algo).

I don't understand how this makes any sense at all.

[fruitworks]

I've looked into the "source code", and it doesn't. There is no such thing as useful PoW. Qubic isn't actually a decentralized cryptocurrency. It's closed source, runs as a EFI executable, and is only accessible from their discord channel.

The attack is no different than paying miners to join a malicious pool. It works as long as money flows in.

[OneDeuxTriSeiGo]

There is such a thing as useful proof of work. Qubic may not be doing it but it does exist. The linked papers [1][2] are examples of way to do it. They aren't 100% "useful" but rather achieve partial efficiency by essentially forcing miners down random paths in a manner that limits the ability to complete work ahead of time or otherwise "cheat".

1. https://eprint.iacr.org/2021/1379

2. https://eprint.iacr.org/2023/1059

[fruitworks]

Gain media attention and pump their coin.