Chia's Green Paper

Download Green Paper

The Green Paper details a new consensus algorithm called Proofs of Space and Time, “PoST”. PoST replaces the proofs of work in Bitcoin’s mining which wastes massive amounts of energy and is less secure to mining centralization.


Learn more

We have academic papers and presentations that give detail about our new consensus algorithm and blockchain software. In 2019 we revealed our Green Paper outlining the construction of Proofs of Space and Time and illustrating many of the design choices of Chia. There is also a 2019 talk from Mariano Sorgente at MIT on how to achieve Nakamoto consensus with Proof of Space and VDFs.

Bram Cohen presented at Stanford on February 2018 on Proofs of Space. Our advisors, Dan Boneh, Benedikt Bünz, and Ben Fisch published a survey of VDFs which are the underlying technology of Proof of Time. Lipa Long published an explanation of class groups that our Proofs of Time is based on. Bram presented Beyond Hellman’s Time-Memory Trade-Offs with Applications to Proofs of Space at BPASE ‘18 in January 2018 based on the academic paper and these slides by Hamza Abusalah. Ben Fisch gave a talk at BPASE 2018 in January 2018 on Verifiable Delay Functions. Bram spoke at Blockchain at Berkeley (which starts about 20:00) in March 2018 with slides. Bram gave a talk at BPASE 2017 in January 2017 on removing waste with Proofs of Space and Time (slides).

Bram gave a talk at SF Bitcoin Devs Seminar about data structures for scaling Bitcoin with slides and Merkle Set code. Bram gave a talk at SF Bitcoin Devs Seminar about removing waste from cryptocurrencies.