I know I'm butting in and I apologize. I can see there are alot of well informed people in this thread with solid arguments one way or the other and I would like you gentleman if you'd be so kind to relay onto me your opinion about multi-pow (separate algorithms mining independently on the same chain), pros ? cons ?
I'd really like to hear what you gentlemen have to say about it.
Is it more viable as a means to secure the chain further ?
Is it more viable for a fairer and wider distribution of the coins ?
Disclaimer: I'm part of the team for such a coin (Myriad) but am not the creator of the concept. I joined the team because I liked the concept and it seems pretty solid.
The main problem with multi-POW coins is that it is difficult to work out how to fairly and securely weight the security factor attributed to each algorithm.
Myriad uses a weighted model (
code here). This means that a SHA256 block needs to have a difficulty 4096 times that of a Scrypt block for them to have equal security weighting. I haven't thought too much about the economic and security implications of this but I know that the weights shouldn't be fixed because the actual difficulty of mining a certain block depends on the type of hardware used.
Also miners rarely care about the security factor (it only comes into effect when there is a fork/orphaned block), so it is easy for the developer to change the weights without requiring the miner's explicit consensus (the change does not lead to long lasting forks).
On the other hand multi-POW coins have more decentralised coin generation (not necessarily security because of the weighting) which is theoretically good for the coin economy.