So I want to create a casino contract. Can I use a hash of all addresses that participate in the casino as a source of randomness?
I'd think yes, as there would be lots of users that have played the casino and an attacker would need to make lots and lots of accounts to be able to influence the hash to a predictable value (and no other users may join or he will need to restart his attack.
As I am not a security expert, I would like to know your opinion on the security of my idea.
I was also thinking of adding some kind of stake requirement to the hashing, like only hash the addresses that are in the top 25% of investments. Then the attacker would need to have quite some stake in the casino before trying to game the system.