TL;DR: small code differences, but many larger ecosystem differences
IIRC, Dogecoin is a fork of Luckycoin, which in turn was forked from Litecoin, which was forked from Tenebrix, which was forked from Bitcoin. As far as I can tell, the main differences to Bitcoin are:
scrypt hashing algorithm
1 minute block interval
accelerated reward schedule:
Full supply ...
It comes up that Bitcoin network has better security. Is that due to the hashrate ? If more miners start switching to Doge, wouldn't that solve the problem ?
Security in Bitcoin is not just about hashrate although it is one of the important things to consider. Other things related to security:
Bitcoin Core: One of the top 10 C++ critical open source ...