Proof-of-activity (PoA)

Proof of activityProof of activity is a consensus mechanism used in decentralized blockchain networks to validate transactions. It is a hybrid approach that combines aspects of proof of work and proof of stake consensus mechanisms.

Proof of workProof of work and proof of stakeproof of stake are both designed to prevent 51% attacks - a malicious action in which one individual or party controls a majority of the mining power in the cryptocurrency network and can then include invalid transactions in the blockchain. Proof of activity combines these mechanisms into a single two step-process:

Proof of activity is a clever hybrid consensus mechanism that blends proof of work with proof of stake to validate new blocks and secure the blockchain.

How Does Proof of Activity work? / image: Coinbold

Here is an overview of how it works:

1. Like PoW, miners compete to solve a cryptographic puzzle using computational power to create a valid block header. This determines who gets to generate the new block.
2. The new block header is then broadcast to the network for the PoS validation phase.
3. Validators who have staked coins on the network then attest that they accept the new block as valid and sign the block header.
4. Once a majority of validators sign off on the new block, it is added to the blockchain.
5. The miner who created the valid header also submits a reward address to claim their mining reward.
6. So in summary, PoA goes through two phases: PoW competition to create the block followed by PoS majority validation before the new block is ready to be added to the chain.

This hybrid approach aims to get the best of both worlds – the security of PoW mining combined with the efficiency and scalability potential of PoS validators.

Proof of activity is a clever hybrid consensus mechanismProof of activity is a clever hybrid consensus mechanism that blends proof of work with proof of stake to validate new blocks and secure the blockchain.

Proof of activityProof of activity is a consensus mechanism used in decentralized blockchain networks to validate transactions. It is a hybrid approach that combines aspects of proof of work and proof of stake consensus mechanisms.

Proof of workProof of work and proof of stakeproof of stake are both designed to prevent 51% attacks - a malicious action in which one individual or party controls a majority of the mining power in the cryptocurrency network and can then include invalid transactions in the blockchain. Proof of activity combines these mechanisms into a single two step-process:

Proof of activity is a clever hybrid consensus mechanism that blends proof of work with proof of stake to validate new blocks and secure the blockchain.

How Does Proof of Activity work? / image: Coinbold

Here is an overview of how it works:

1. Like PoW, miners compete to solve a cryptographic puzzle using computational power to create a valid block header. This determines who gets to generate the new block.
2. The new block header is then broadcast to the network for the PoS validation phase.
3. Validators who have staked coins on the network then attest that they accept the new block as valid and sign the block header.
4. Once a majority of validators sign off on the new block, it is added to the blockchain.
5. The miner who created the valid header also submits a reward address to claim their mining reward.
6. So in summary, PoA goes through two phases: PoW competition to create the block followed by PoS majority validation before the new block is ready to be added to the chain.

This hybrid approach aims to get the best of both worlds – the security of PoW mining combined with the efficiency and scalability potential of PoS validators.

Proof of activity is a consensus mechanism used in decentralized blockchain networks to validate transactions. It is a hybrid approach that combines aspects of proof of work and proof of stake consensus mechanisms.

Proof of work and proof of stake are both designed to prevent 51% attacks - a malicious action in which one individual or party controls a majority of the mining power in the cryptocurrency network and can then include invalid transactions in the blockchain. Proof of activity combines these mechanisms into a single two step-process:

1. Proof of work for miners to compete to find the block and earn the block reward. The greater percentage of the network's total computing power a miner has, the greater the probability that they will find a block.
2. Proof of stake to validate/sign the new block. The greater the percentage of the total cryptocurrency supply a staker has, the greater the probability that they will be chosen to validate the block.

Proof of activity adds a second line of defense against 51% attacks because an attacker would theoretically need to have both 51% or more of the network's total mining power and 51% or more of the coins staked in the network in order to successfully pull off the attack.

Decred is a cryptocurrency that uses the proof of activity consensus mechanism. Espers is another.