III. Consensus Mechanism
Question 21: What kind of consensus mechanism does SCDO use?
Answer: SCDO uses an improved version of the proof of work consensus mechanism, called ZPoW (Zero Proof-of-Work) consensus. In fact, ZPoW belongs to the PoW category but has been optimized to address many issues present in traditional PoW (such as power monopolization, resource waste, etc.).
All nodes in the SCDO network participate in block generation competition through hash calculations, and successful participants will obtain the bookkeeping rights and block rewards of new blocks. Although it is still fundamentally 'power is king,' SCDO has innovated on the details of the PoW algorithm to ensure that competition among miners is fairer, more efficient, and more environmentally friendly. It is particularly noteworthy that SCDO's mainnet does not adopt consensus mechanisms such as Proof of Stake (PoS) or Delegated Proof of Stake (DPoS), but adheres to the PoW route, significantly enhancing the fairness and security of PoW through ZPoW.
Question 22: What are the characteristics of the ZPoW consensus algorithm?
Answer: ZPoW is an innovative PoW algorithm characterized mainly by: First, focusing on scientific computing: The ZPoW algorithm utilizes problems that require continuous computation and are difficult to parallelize (such as matrix calculations).
This means that GPUs cannot easily parallel accelerate like processing simple hashes, thus reducing the advantage of specialized mining machines over ordinary computers.
Secondly, adopting a multi-target computing framework: ZPoW has designed a hybrid multi-algorithm mining framework, allowing miners to choose different computational tasks, each with its own independent difficulty and dynamic adjustments. If a particular algorithm sees too many miners, leading to high block generation frequency, the network will increase its difficulty and decrease its output probability, encouraging miners to shift to other algorithms for a more balanced opportunity to generate blocks across computational targets. Furthermore, CPU friendly: Through the aforementioned mechanisms, ZPoW significantly reduces the advantage of GPUs/ASICs over CPUs, allowing ordinary hardware to be competitive. Finally, the difficulty of a 51% attack is higher: since attackers must dominate multiple computational targets to continuously generate blocks, the actual difficulty of launching a 51% attack is several times higher than traditional PoW. Overall, ZPoW inherits the security and anti-censorship characteristics of PoW while improving fairness and security margins through technical means, making it a cornerstone for the stability of the SCDO network.
Question 23: What are the differences between ZPoW and traditional PoW such as Bitcoin?
Answer: Compared to Bitcoin's SHA-256 PoW, ZPoW differs in algorithm form and strategy:
Algorithm Complexity: Bitcoin's PoW pursues simple hash collisions, easily accelerated by ASIC chips; ZPoW, on the other hand, employs complex computations (such as random matrix determinants), making it difficult to develop dedicated mining machines.
Hardware Friendliness: Traditional PoW heavily relies on high-performance hardware, making it almost impossible for ordinary users to gain competitiveness using CPUs; ZPoW minimizes parallel advantages, allowing ordinary hardware to participate in mining.
Multi-algorithm Mixing: Bitcoin only has a single algorithm, which has a high risk of power centralization; ZPoW introduces various computational tasks to dynamically balance and avoid monopolization of a single algorithm.
Energy Consumption: Bitcoin's PoW consumes astonishing amounts of electricity due to large-scale power competition; ZPoW, designed with more efficient computations (useful calculations or reducing unnecessary computations), has lower energy consumption under the same security level.
Difficulty Adjustment: Both have difficulty adjustment mechanisms to ensure target block generation time; Bitcoin adjusts every 2016 blocks, while SCDO's difficulty adjustment is more flexible (potentially more frequent or independently adjusted by algorithm) to adapt to the mixed algorithm architecture. Overall, ZPoW is a deep improvement over traditional PoW, aiming to retain the decentralization and security of proof of work while addressing its efficiency and fairness issues.
Question 24: Why did SCDO choose PoW instead of PoS or other consensus mechanisms?
Answer: Although PoS has gained popularity in many new chains in recent years, SCDO chose PoW mainly based on the following considerations: First, PoW has been validated by Bitcoin and others over more than a decade and is considered the safest and most reliable public chain consensus to date, effectively resisting witch attacks and falsifying historical records. The SCDO team upholds Satoshi Nakamoto's fair ideology and aims to continue the security model of 'Proof of Work = Actual Resource Investment.'
Secondly, the entry threshold for PoW is relatively open and transparent—anyone can become a miner and participate in the competition, while PoS often faces issues of uneven initial distribution or whale monopolization of tokens.
SCDO does not have pre-mining or private placements, and chooses PoW to ensure the fairness of token distribution, preventing the network from being controlled by specific interest groups in its early stages.
Secondly, from the perspective of decentralization, nodes in the PoW mechanism do not need to trust identities and rely on computing power to speak, making it easier to reach a consensus globally, while PoS may weaken decentralization due to the concentration of stakeholders.
Finally, SCDO optimizes the resource consumption and efficiency of PoW through ZPoW, significantly reducing its shortcomings, thus providing more reasons to adhere to the PoW route. In summary, SCDO believes that the improved PoW can provide a more solid guarantee in terms of security and decentralization, making it the best choice for realizing the project's vision, while also using technological innovation to compensate for the performance shortcomings of PoW.
Question 25: How does ZPoW improve the fairness of ordinary users participating in mining?
Answer: The ZPoW algorithm ensures that more ordinary users can participate in mining and maintaining the network through various mechanisms: 1. Reducing hardware disparity: Because ZPoW's problem design requires continuous computation and is not easy to parallelize, specialized mining machines and large GPU clusters cannot completely suppress ordinary PCs, allowing home computers, laptops, and even CPUs to have opportunities to participate and succeed. 2. Multi-algorithm balance: ZPoW allows miners to choose different algorithms for mining; if a certain algorithm is dominated by large miners, its difficulty will increase and yields will decrease, allowing other miners to choose less competitive algorithms, thus avoiding everyone crowding into the same track being suppressed by large miners. 3. Reward mechanism optimization: SCDO considers allowing even miners who have not yet generated blocks to accumulate during continuous work (for example, providing computational proofs to increase the success rate for the next attempt). This means that small miners will have an increased probability of generating blocks over time, unlike traditional PoW where block generation relies solely on instantaneous computational luck. 4. No pre-mining + community activities: The official team did not reserve any mining, but instead encouraged early miners from different regions and abilities to join through genesis rewards and community incentives. These measures enhance the breadth and enthusiasm of mining participation. Overall, ZPoW makes SCDO mining closer to the ideal state of universal participation, resulting in a more balanced distribution of network computing power and thus improving the overall fairness and health of the system.
Question 26: How is the energy consumption and efficiency of ZPoW consensus? Is it more energy-efficient than traditional PoW?
Answer: Compared to traditional PoW, ZPoW has made improvements in energy consumption and computational efficiency. By introducing scientific computing algorithms, ZPoW avoids the waste of purely repetitive hashing, allowing the mining process to utilize the actual processing power of processors more efficiently. This means that in generating blocks with the same level of security, ZPoW ideally consumes less electricity. At the same time, ZPoW reduces the demand for high-energy-consuming dedicated mining machines, as ordinary hardware can also participate, potentially reducing the energy invested in pursuing the limits of hash rates from a network-wide perspective. According to community tests, the SCDO network has significantly lower energy consumption per unit of computing power compared to the Bitcoin network. However, it should be noted that ZPoW is essentially still a PoW mechanism, and miners inevitably need to consume electricity to perform proof of work, so absolute energy consumption will still rise with the growth of the total network's computing power. It's just that under the same security conditions, ZPoW's design is more efficient and energy-saving. The SCDO team also places great importance on environmental protection and will continue to optimize the algorithm to make computations beneficial (for example, tasks that may help scientific computing in the future) to utilize energy more effectively. In balancing PoW and energy consumption, SCDO's performance is relatively friendly, but investors and miners still need to pay attention to electricity costs and carbon emissions.
Question 27: How does SCDO's consensus mechanism prevent 51% attacks and other security threats?
Answer: SCDO significantly increased the difficulty of launching a 51% attack through the special design of ZPoW. In traditional PoW, if an attacker possesses more than half of the total network's computing power, they can continuously produce a private chain, allowing for double-spending or rewriting history. In SCDO, first, the mixture of multiple algorithms prevents attackers from monopolizing a single algorithm. If the ZPoW framework provides up to 10 computational targets, attackers need to achieve over half of the power on all targets to continuously win new blocks, effectively increasing the attack difficulty by an order of magnitude (for example, 10 types of tasks make the difficulty nearly 10 times higher). Secondly, SCDO miners come from a broader group, resulting in a more uniform distribution of computing power, making it harder for a single entity to obtain a majority of the network's power. Furthermore, the SCDO network has a fast block generation frequency and shard parallelism, requiring attackers to simultaneously control multiple shard chains, which adds to the complexity. Additionally, if a suspected attack occurs (such as abnormal block generation in a shard over a long period), the community and development team will intervene in a timely manner, alleviating the situation through node upgrades or parameter adjustments. Overall, ZPoW significantly reduces the likelihood of a 51% attack occurring through an algorithm balancing mechanism, making it difficult for attackers to maintain an advantage even with substantial resources, thus providing SCDO with stronger resistance to attacks compared to traditional PoW.
Question 28: Does SCDO's consensus algorithm adopt a mix of various mining algorithms?
Answer: Yes, a key feature of the ZPoW consensus is the multi-algorithm mixed mining framework. Simply put, the network sets various types of computational tasks as proof of work, each with its own target difficulty. Miners can choose any of the algorithms to compute their workload. Some algorithms may favor CPU computation, while others are more suitable for GPUs, each with its own strengths. The dynamic difficulty adjustment mechanism ensures that all algorithms have balanced opportunities for block generation: if a particular algorithm sees an influx of miners and generates blocks too frequently, the system will increase its difficulty, making other algorithms relatively easier to generate blocks, thus encouraging miners to shift. This model, akin to a “parallel race of multiple mining algorithms,” ensures that no single computational path is monopolized. The algorithms currently implemented in ZPoW include matrix calculations, scientific function calculations, etc., and others can be added in the future. Miners can even attempt multiple algorithms simultaneously to increase their chances of winning. The benefits brought by mixed mining include enhanced network security (the coexistence of multiple algorithms makes it difficult for attackers to manage all at once) and increased decentralization (miners with different hardware strengths all have a place). This is one of the major improvements of the SCDO consensus mechanism compared to traditional single-algorithm PoW.
Question 29: How do SCDO mainnet and sidechain connect in terms of consensus?
Answer: The SCDO mainnet and Stem sidechain have an independent yet interrelated relationship in terms of consensus. The mainnet adopts ZPoW consensus, maintained by global miners, ensuring its security and data immutability.
Each sidechain can choose a consensus algorithm suitable for itself, such as PBFT (Practical Byzantine Fault Tolerance) or PoS, to achieve internal consensus within the sidechain.
This means that block generation for the sidechain is determined by the sidechain's own nodes based on the sidechain consensus, and sidechain transactions are not directly verified by mainchain miners.
Nevertheless, the mainchain supervises the sidechains through smart contracts: sidechains must regularly submit state hashes to the mainchain, effectively filing the latest state of the sidechain with the mainchain.
Mainchain miners will package this hash into mainchain blocks, making it irreversibly recorded on the entire network. Furthermore, if disputes arise, anyone can submit the sidechain transaction data for mainchain verification (challenge), which will be adjudicated by mainnet miners.
Therefore, the mainchain consensus provides the ultimate security endorsement for the sidechains: even if a certain sidechain's internal consensus may be relatively weak (such as PoS being controlled by a few), attackers cannot alter its final state to evade mainchain supervision.
It can be said that the SCDO mainchain and sidechains form a main-sub collaborative consensus system: the mainchain maintains the global trust root, while the sidechains operate efficiently and independently but must periodically report to the mainchain to earn trust from the entire network.
Question 30: Will SCDO adjust or upgrade its consensus mechanism in the future?
Answer: As of now, the SCDO team has no public plans to switch the mainnet from PoW to other consensus mechanisms, and the mainnet will continue to adhere to the ZPoW consensus to maintain the advantages of decentralization and security.
However, the team will upgrade and improve the implementation of the ZPoW algorithm as needed, such as adding more types of computational tasks and optimizing difficulty adjustment algorithms to further enhance efficiency and security.
On the other hand, SCDO has provided a pathway for compatibility with other consensus through the Stem sidechain—such as implementing PoS or PBFT on the sidechain to adapt to specific application scenarios.
Therefore, it is unlikely that the mainchain will easily change its consensus mechanism, as this relates to the fundamental attributes of the network, and the current operation of ZPoW is stable, secure, and reliable.
If better consensus solutions emerge in the blockchain field in the future and are validated, the community and team may discuss the introduction (for example, as a sidechain or extension module).
However, in the short term, SCDO's mainnet will maintain the established ZPoW consensus and continue to optimize. Any performance improvements will prioritize downward compatibility and robust transitions based on ensuring security and decentralization, without hastily changing the core consensus.