Do multi-PoW currencies open up additional attack vectors on a blockchain?

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I'm curious if there have been any technical evaluations of the vulnerabilities of cryptocurrencies that utilize more than one proof of work algorithm - for instance, myriadcoin or huntercoin.

Myriadcoin uses five different PoW algorithms, with different algorithms targeted towards different hardware, so that people are able to mine with ASICs, GPUs, and CPUs. The idea is that this will make it more difficult to centralize mining and harder gain control of 51% of the hashing power, while also making mining more accessible to as many people as possible.

I'm wondering if there are any potentially unintended consequences to this that maybe some folks have already identified.

jwinterm

Posted 2016-08-09T18:39:25.963

Reputation: 225

Answers

-1

Chaining algorithms reduces security as if one part of the chain fails, the whole chain fails. And in this case fail doesn't just mean completely broken, it can also mean an ASIC-proof algorithm turning out to be not ASIC proof.

Jannes

Posted 2016-08-09T18:39:25.963

Reputation: 5 823

1Myriad's approach is not a chained algorithm (like X11) but independent algorithms working on the same blockchain tip. Does that change your analysis in any way? – None – 2016-08-10T12:35:17.480

What cryptapus said. Although myriad uses chained algos for two of its five hashing algorithms (myr-groestl and qubit, and qubit is soon to be dropped for yescrypt), that isn't the question I was asking. I was asking about the potential vulnerabilities or security issues with respect to using multiple PoW algorithms - consider huntercoin which uses only sha and scrypt if you like.jwinterm 2016-08-10T15:16:40.557

Never even heard of myriad. I don't keep track of all the scam coins out there. In general complexity is the enemy of security (and proper incentives) and this sounds complex without purpose.Jannes 2016-08-10T21:10:34.510

I stated the purpose in the question - this will make it more difficult to centralize mining and harder gain control of 51% of the hashing power, while also making mining more accessible to as many people as possible. Based on your answer above and this comment, it appears you didn't even read the question.jwinterm 2016-08-11T18:07:02.657

I hadn't actually read it in that way no, i get the idea now. Assuming they set up these 5 algorithms such that they can have independent difficulties automatically adjusted to keep a fair ratio (if that's even possible), then the next problem is that there's actually no such thing as an "ASIC proof" algorithm. As soon as the coin makes it with the effort, someone will create an ASIC for each of those algorithms. So it's a nice selling point (tried and tested) but it can't last, therefore scam.Jannes 2016-08-12T09:30:20.303