> Consider all coins using the same function to be the same family and the one with the most work and power to be the most valid. So there are sha256 coins, scrypt coins, equihash coins, etc. In the case of sha256 the most immune to attack is bitcoin. Everything else is massively vulnerable.
This is a really good point, and part of what I am hoping people come to understand from this website. Ignoring the risk of renting power from NiceHash to launch an attack, large existing miners could easily switch to a smaller coin for a few hours to attack it, and typically it would be very profitable.
I wonder whether the indirect benefits of discouraging competing coins would outweigh the costs of loss of confidence in crypto currency is in general (and the computer cost).
This is a really good point, and part of what I am hoping people come to understand from this website. Ignoring the risk of renting power from NiceHash to launch an attack, large existing miners could easily switch to a smaller coin for a few hours to attack it, and typically it would be very profitable.