## 4 Nazzfast Consensus Mechanism
### Block Creation Cycle
#### 4.4.1 Block Proposal Phase
Almost every blockchain consensus encounters this type of attack in its network. In this attack, a single entity has very high powers in the network. It might be because of its high stakes or computational power in the network. It can lead to a 51% attack [86], in which the majority has the ruling power of the network. Our consensus may resist this attack under the following conditions. _Result:_ This attack affects the decentralized nature of the blockchain network. Our consensus tries to avoid the influence of a single entity in the network by using S&Sem. The S&Sem has multiple factors to get selected for the block producer, such as total time calculation, stake value, voting, and randomization. Because of all these factors, a single entity cannot control the whole system. _Condition:_ Grinding attacks are also very dangerous for blockchain networks [87]. A validator may precompute the protocol so that it can manipulate the block producer selection process to select it as the block producer/slot leader for the next block creation cycle. Some protocols use randomness to avoid this attack [88]. We also control the attack in our network with the below solution. _Result:_ We used S&Sem in our network, and S&Sem reduces grinding attacks since it is very difficult to pre-determine the block producer in the network. The S&Sem process creates so many constraints for the validators that they cannot become block producers by forgery. It is not easy for the validator to manipulate the network and become a block producer by using any incorrect approach in S&Sem. _Condition:_ In a coin age accumulation attack, a validator may have enough time and resources so that it can manipulate the system by its powers. The attack is also addressed by others in the literature, such as [57]. In this attack, due to the saturation of resources, an adversary can easily be selected for the block producer/slot leader in the selection. The Initial consensus of PoS used the coin age mechanism in its consensus for block validator selection, such as PPCoin [89]. Coin age calculation depends on the number of coins. Coin age calculation is used to strengthen the consensus by encouraging long-term participation in the network. We also used this technique in our election mechanism, S&Sem. The coin age technique is very useful for engaging the validators long-term in the network. It improves the liveness of the network. However, due to coin age calculation for validator selection, it may lead to coin age accumulation attack [90; 91]. _Result:_ By using S&Sem and Sea Shield together, we control this attack in our system. The S&Sem used other parameters with coin age calculation, such as stake value, extra bonding time commitment, vote value, and randomness. Coin age calculation is also secured by Sea Shield because we use a validator chain to store coin age, stake value, and extra bonding time in the network; therefore, manipulation is not possible with the data record. Block Double Production Attack

_Condition:_ In this attack, a block producer produces many blocks simultaneously at a single height to pollute the network system [92]. It can lead to other attacks in the system as well, such as short-range or long-range. Our system may encounter this attack. _Result:_ Our block producer may create and broadcast multiple blocks together at their turn to the block-validating committee of the network. Our system will resist this attack logically. Our network system allows one block at one height during the block creation cycle. If any member of the block creation committee receives multiple blocks from a similar sender (sender confirmation by the digital signature of the block), it will only consider the first block that it has received from it and discard the remaining received blocks. The block creation cycle will only proceed for a block that has 2/3 prevote.