Emercoin Security Principles
Inheriting all the security advantages of bitcoin, Emercoin uses peer-to-peer technology to operate without a centralized authority. Transaction verification and currency issuance is carried out collectively by the network through consensus. All records are completely decentralized and uncensorable and cannot be altered, revoked or suspended by any authority.
But with PoW and PoS working in tandem, the Emercoin blockchain possesses an enhanced degree of security. A 51% attack on Emercoin would require someone having both a minimum of 51% of the network hashpower and at least 51% of the total coin supply in their possession. Such an attack on the Emercoin blockchain would be a self destructive move by the attacker since they would simultaneously be damaging the network and devaluing their own massive coin holdings.
Now that Emercoin is merge-mined with Bitcoin, it benefits from a significant portion of the mining power of the Bitcoin network.
Technically a 51% attack on Emercoin would have been possible before merge-mining began but it would have been a fruitless move that required spending a large sum of money to perform, and only someone with several million dollars to waste and a serious grudge against the Emer blockchain would have had the means to do it.