Kaspa's kHeavyHash mining algorithm traces back to a 2019 optical proof-of-work paper

An algorithm built for hardware that does not exist yet

#Kaspa's proof-of-work algorithm, kHeavyHash, has an unusual origin. The design traces back to a 2019 paper titled "Optical Proof of Work," authored by Michael Dubrovsky, Marshall Ball, and Bogdan Penkovsky, and published on arXiv. The authors wanted to shift the dominant cost of mining away from electricity and into the hardware itself, a goal they believed photonic, or light-based, chips could achieve.

One of the forward-looking aspects of kHeavyHash is its compatibility with optical mining, an emerging technology that uses light-based computation instead of traditional electronic computation. While optical mining is still in development and not yet widely available, kHeavyHash was designed with this future technology in mind.

The algorithm's structure reflects that intent. A matrix multiplication step sits between two Keccak-family hashes drawn from the SHA-3 standard. That middle step is particularly well-suited for optical processing, which excels at matrix operations central to kHeavyHash. In theory, photonic chips could handle this workload far more efficiently than conventional silicon.

ASICs fill the gap while optical hardware waits

In practice, $KAS mining runs on conventional ASICs. KAS mining moved from GPU-dominant to ASIC-dominant almost overnight when IceRiver launched the first kHeavyHash ASIC. IceRiver was there first, launching the original KS0, KS1, and KS2 Kaspa miners before any other manufacturer had produced dedicated kHeavyHash hardware. Bitmain followed with its Antminer KS series, and the competitive landscape has intensified since.

GPUs are no longer viable for Kaspa mining. Dedicated kHeavyHash ASICs, led by Bitmain's KS series and IceRiver's lineup, deliver 100 to 1,000 times the hashrate of a high-end GPU at a fraction of the power consumption. Bitmain's Antminer KS3 (8.3 TH/s) and KS5 (15 TH/s), alongside IceRiver's KS0 through KS5 lineup, now cover different budgets and scales.

The optical hardware the algorithm was originally designed for has yet to arrive. Optical mining remains experimental and is not yet available for commercial use. However, kHeavyHash's design ensures that when this technology becomes viable, Kaspa will be positioned to take advantage of it. For now, the gap between the algorithm's theoretical foundation and its real-world deployment remains wide.

Sources:
Optical Proof of Work, arXiv (2019)
kHeavyHash Proof-of-Work Algorithm, Kaspa Wiki
Kaspa ASIC Mining Explained, MiningReturns