hello list,

would it be possible to have two available POW mining algorithms (like
for example "Double-SHA256" and "Cuckoo Cycle"), and let the miner
choose which one to use for POW?

the two algorithms would have independent difficulties, and after each
difficulty period, the difficulty would be adjusted to aim for 50/50
distribution of the two algorithms (in addition to aim for 10 minutes
block time).

this could be done by only adjusting up difficulty for the algorithm
used in most blocks last period, or only adjusting down difficulty for
the algorithm with the least number of blocks last period (depending
on whether the combined difficulty was to be adjusted up or down).  or
maybe a more sophisticated variant, where both difficulties are
adjusted, based on the relative difference of the number of blocks
where they are used.

the main motivation for this would be:

- increase mining distribution
- continue mining even when one type of miners suddenly jump to mine a
  more profitable altcoin.

not sure if this has been proposed (and rejected) before, but I can't
remember seeing it discussed.

would probably require a hard fork.

SA