Secure Proof of Stake (SPoS) is a consensus mechanism to improve the traditional (PoS) algorithm.
While PoS relies on token staking for validation, SPoS introduces additional elements for enhanced security and efficiency.
How does SPoS work?
1. Validators
Unlike PoS, where any stakeholder can potentially be a validator, SPoS designates specific nodes as validators responsible for transaction verification and block creation.
These validators are randomly selected based on their stake in the network’s native token and other metrics.
2. Staking
Similar to PoS, participants in an SPoS network lock their tokens in a smart contract as a form of commitment and collateral.
The larger the stake, the higher the chance of being chosen as a validator.
3. Random Validator Selection
This is a key differentiator of SPoS. Instead of relying solely on stake size, SPoS introduces randomness in the validator selection process.
This prevents a small group of large-stake validators from gaining excessive control, reducing centralization risks.
4. Deterministic Finality
Unlike PoS, where finality (the point at which a transaction is irreversible) can be uncertain, SPoS provides a fixed timeframe for finality.
This means that once a block is added to the chain, it cannot be altered beyond a specific timeframe, enhancing security and reducing uncertainty.
SPoS vs. PoS
Similarities
SPoS and PoS rely on staking tokens to incentivize participation in the consensus process.
They also aim to provide a more energy-efficient alternative to PoW.
Differences
1. Validator Selection
PoS allows any stakeholder to participate in validation, while SPoS uses a random selection process for Shards.
2. Finality
PoS can have some uncertainty around finality, while SPoS provides deterministic finality within a fixed timeframe.
3. Scalability
SPoS, with its Dynamic Sharding feature, is more scalable than PoS.
SPoS in the Elrond Network
Elrond Network implements its version of SPoS, Secure Proof of Stake + Sharding (SPoS + Sharding).
This combines SPoS with Sharding, a technology that divides the network into smaller segments for parallel processing.
This further enhances scalability and transaction speed.
This version introduces additional features like:
1. Adaptive Sharding
The number of shards can dynamically adjust based on network load, further optimizing resource utilization.
2. Nominated Proof of Stake (NPoS)
Users can delegate their stake to validators they trust, increasing participation and accessibility.
In summary, Secure Proof of Stake (SPoS) in the Elrond Network builds upon the traditional Proof of Stake concept by incorporating features such as Adaptive State Sharding, random selection with identity, and epoch changes to enhance security, decentralization, and scalability.
The aim is to create a high-performance blockchain supporting a broad range of decentralized applications.