Proof of Capacity (PoC) | cryptocurrencies, blockchains & live prices

Proof of Capacity (PoC), also known as Proof of Space, is a consensus mechanism in which miners dedicate hard drive storage space rather than computational power to secure the network. Before mining begins, participants fill their hard drives with precomputed solutions called plots. When a new block needs to be produced, the network issues a challenge and miners scan their stored plots to find the closest matching solution. The miner whose plot contains the best match wins the right to forge the next block.

The primary advantage of Proof of Capacity is its energy efficiency compared to traditional Proof of Work. Since the computationally intensive work of generating plots is done only once upfront, the ongoing mining process requires minimal electricity — just reading from a hard drive. This makes PoC far more environmentally friendly and accessible, as hard drive storage is inexpensive and widely available. The trade-off is that PoC networks can be vulnerable to large-scale storage farms and the initial plotting process still requires significant computational resources and time.

The most well-known blockchain using Proof of Capacity is Chia Network, created by Bram Cohen, the inventor of BitTorrent. Chia uses a refined version called Proof of Space and Time, combining storage plots with a verifiable delay function. Another early adopter was Signum (formerly Burstcoin), which was one of the first cryptocurrencies to implement PoC mining. These projects have demonstrated that storage-based consensus can offer a viable, greener alternative to energy-intensive mining while maintaining adequate network security.