Glossary

Secure Proof of Stake (SPoS)

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Secure Proof of Stake (SPoS) is a consensus mechanism used to secure blockchain networks. It is an evolution of the traditional proof-of-stake (PoS) consensus algorithm.

What Is Secure Proof of Stake (SPoS)?

Secure Proof of Stake (SPoS) is a consensus mechanism used to secure blockchain networks. It is an evolution of the traditional proof-of-stake (PoS) consensus algorithm. In PoS, instead of miners solving complex mathematical problems to validate transactions and create new blocks, validators are selected based on the amount of stake they hold in the network. In SPoS, validators are selected based on their reputation and stake in the network, as well as the security and efficiency of the nodes they run.

The SPoS mechanism aims to provide higher security and decentralization compared to traditional PoS algorithms. It incentivizes validators to act in the network's best interest by combining security measures, such as random sampling, reputation-based selection, and network-wide consensus.

How does Secure Proof of Stake (SPoS) (Elrond Network) work?

Secure Proof of Stake (SPoS) combines random validators' selection and eligibility through stake and rating with an optimal dimension for the consensus group.

Each node in the network is defined by a public key, a rating and the amount of stake it has locked up. To participate in the consensus, a node must first register through a smart contract by sending a transaction containing the minimum required stake and other information such as its public key and its node ID.
At the end of each epoch, the node is moved to the list of eligible nodes (Ej) of a shard j. The node can then be selected as part of a consensus group, Nchosen, by a deterministic function based on the randomness source added to the previous block, the current round, and a set of variation parameters.
The block is created by the block proposer, and the validators co-sign it using a modified version of the Practical Byzantine Fault Tolerance (pBFT) algorithm. If the block proposer fails to create a block within its allocated time slot, the round and randomness source from the last block are used to select a new consensus group.
The SPoS mechanism provides several advantages, including partitioning the blockchain and account state into multiple shards that can be handled in parallel by different validators and an improved variation of Proof of Stake (PoS).

Proof of Stake vs Secure Proof of Stake (Elrond Network)

Proof of Stake (PoS) and Secure Proof of Stake (SPoS) are similar consensus mechanisms with a few slight differences. In PoS, validators are selected based on the amount of stake they hold in the network. In SPoS, they are selected based on multiple criteria such as stake, reputation and the security and efficiency of their nodes. 

This results in higher network security and a smaller attack surface. Additionally, SPoS provides higher decentralization compared to PoS as validators are selected from a larger pool of nodes, leading to a more diverse consensus group. 

In conclusion, both algorithms are suitable for securing blockchains and are popular choices among developers. PoS focuses on staking as the main factor for selecting validators, and SPoS considers additional factors for validator selection.