![choco.png](https://cdn.steemitimages.com/DQmXrXpi3VHY3rfrTFK3wkWjoDLLuFnd4oG6JpdM7SZbE4p/choco.png) ^{Image from [source](https://i.ytimg.com/vi/BzJOvcXvN-4/maxresdefault.jpg)} ^{Image from [canva](www.canva.com)} Blockchain is the new ledger. the world agreeing on one accounting algorithm more the future of book keeping. Consensus algorithm is when all the nodes in the blockchain network comes to a consensus or agreement to validate a block or term the block as valid. There are many known consensus mechanism algorithm, but the popular ones are proof of work, proof of stake, delegated proof of stake and others. Unknown ones such as proof of capacity, proof of burn based on the assignment by our lecturer @alphafx i will be writing on proof of capacity. Proof of Capacity also termed as proof of space, just like proof of work where a miner has to sacrifice significant computation power to mine and in proof of stake where excessive coins are been sacrificed to mine is the same way in proof of capacity significant space in hard drive is been sacrificed to mine. Proof of capacity makes use of hash known as shabal. Proof of capacity is a consensus mechanism algorithm whereby a significant amount of storage on nodes hard drive is used to store available solutions inorder to solve a hashing problem of cryptocurrency thereby leading to which node will be granted the mining power if these nodes available solutions leads to a minimum deadline value over other nodes. The available spaces on the nodes hard drive has to be large inorder to store more available solutions, because the more space on the hard drive enables more solutions to be stored. **How does proof of capacity work** It involves two steps that is plotting and mining. **Plotting** Before the hard drives is inserted they are plotted to create nonces (storage volume of numbers used once).These nonces are produced through continue hashing of data, each nonce contains 8192 hashes which starts from 0-8191hashes,if a node provides more space on its hard drive for plotting, more nonces will be stored on it. These nonce hashes are grouped into two pairs called scoop. These scoop are arranged from 0 for the first pair of nonce that is(#0,#1) till the last pair 4095(#8190,#8191). **Mining Process** Here the scoop are used by miners for computing power for a particular period of time, the miners tend to calculate a particular scoop number which falls between 0 and 4095,the generated scoop number and its corresponding nonce will be used to calculate a deadline value, this process is repeated by calculating all the nonces deadline value in the miners hard drive. Deadline is the time that must expire after the last block was formed before a miner is allowed to form a new block, if a miner is able to form a block within this time before other miners, the miner claims the block reward. Proof of capacity is used by burstcoin, spacemint etc. ![image.png](https://cdn.steemitimages.com/DQmSwgotMDnPDBmQ6cjf6WMHTaa7GZ2BpZAi9vzV7s1HBxK/image.png) Burst coin(BURST):is a cryptocurrency that uses a mining device available hard drive space, burst coin was the first coin to make use of the proof of capacity algorithm, its tokens are known as BURST. Burst coin are available for trading on exchange such as Bittrex, Upbit, Eterbase, Poloniex. **Advantages of proof of capacity.** a)Proof of capacity uses less energy as compared to proof of work. b)Proof of capacity can make use of any hard drive such as laptop and even android mobile hard drive. c) Mining process is cheaper here compared to other consensus algorithm that the miner has to purchase powerful computational devices. **Disadvantages of proof of capacity** a)Available solutions stored on hard drive are later erased and the hard drive is been used for other purpose. b) Proof of capacity is unpopular compared to other consensus algorithm. c)There is possibilities of malware attack. **Summary** I think Proof of capacity mining with time will become popular just like proof of stake and proof of work because it is not quite expensive when compared to them in a sense that that the miner inorder to mine makes use of expensive computational power in proof of work and stake enough coins inorder to mine for proof of stake but in proof of space to mine is just a matter of having available space on the hard disk of the mining device. Thank you for the lectures professor @alphafx.