Can we get an official statement by MaNI if the multi algo design on coins like Myriadcoin and Digibyte is flawed also? Or is it a secret?
After looking into it extensively and much internal debate we have decided that multi-algo as it currently stands is flawed from a security perspective. While it sounds good on the surface there are some rather complex implementation issues in reality which have become apparent while looking at the code, that we are not satisfied can be solved in a reasonable way, or at least I am not confident I can solve them and I feel it is good to know your limits
I don't want to go into too much technical details but most of the flaws revolve around the fact that 'difficulty' is a somewhat arbitrary measurement, while it can be used to meaningfully compare two blocks from the same algorithm to one another, there is no real relation between the difficulties of two different algorithms. i.e. It is not really meaningful to say that a 500 difficulty Scrypt block is worth more or less than a 500 difficulty Groestl block. While it can be determined with some analysis for a specific moment in time with some work it requires a level of 'perfect information' that is not compatible with a p2p crypto currency type system, and even I as a human cannot tell you for a fact that the answer I give you now will still be the same in say six months time.
I have looked at various proposals to try and solves these issues, and what several coins have done and have found theoretical problems and flaws with all of them.
Putting those issues aside there is then the market related issue as well, which is that if you have e.g. 3 algorithms, your reward for each algorithm is 1/3, this is quite likely to attract 1/3 of the hash power for each algorithm, possible even less so in a way even if we can solve the technical issues it is not necessarily going to help form a security perspective.
This is not to say that multi-algo is 'completely broken' the above are of course theoretical i.e. it is not 100% completely trivial to attack a multi-algo coin, and you would still need a reasonable hash rate for at least to do so, so I would not begin a complete panic about other coins. Perhaps time will show differently that the worries are unfounded.
However I would not personally use such an important coin as NLG on which to test theories, I can not in good concious recommend anything that is not 100% theoretically air tight.
There are also some 'non ideal' steps that can be taken to help prevent some of the issues which may involve lots of frequent changes to the coin which we do not want... whether other coins will do this or not depends on the coin.
It is my belief that the security would be likely worse or at best 'on par' with a standard single-algo coin, especially after taking the market factors into account, we don't want to implement something we are not 100% happy with, and we are not 100% happy with multi-algo at this point based on the flaws that have been uncovered, and based also on the possibility that there may be further flaws we are missing (Given that multi-algo has a higher complexity than single algo, simplicity is a desirable characteristic where possible)
We do however feel that the current single-algo is also not ideal, unless we can begin to attract far more hash power, so we are keeping a close eye on this while also looking into other options still.
A potential 'PoS' solution is on the cards, it would likely be added as a compliment to the current 'PoW' so we would end up with two algorithms, however again we must first do our homework and ensure we are completely happy with it before we implement it, so I don't want to make any guarantees just yet.
We will of course continue to look into all avenues to see what is best in the end.
Thanks for the advice. I might buy more to average out my losses and not risk it selling.
