According to Blockworks, StarkWare, the company behind Starknet, announced at Eth Denver that it is building a zero-knowledge prover called Stwo, which is designed to reduce latency and transaction costs. Stwo will be built open source under the Apache 2.0 license, which StarkWare COO Oren Katz said in a press release means that anyone can fork the code, modify and distribute modified versions of the software. Katz said: "Stwo will bring new possibilities for expansion, and it will be open to everyone from day one." In the context of blockchain technology, a zero-knowledge prover refers to a computing entity responsible for determining whether a given piece of information is accurate without revealing its underlying data. These provers must create "proofs" that can be verified by validators. Stwo is not the first open source prover developed by StarkWare. Currently, the public Starknet blockchain and Starknet application chain use its first-generation prover Stone. Katz said that Stwo will be an upgrade of the Stone prover, thanks to the Circle Stark protocol developed by Starkware in cooperation with Polygon. According to StarkWare, the Circle STARK proof of the Circle Stark protocol improves the efficiency of existing STARKs. STARKS on Starknet are considered to belong to the same category as validity proofs on other zero-knowledge blockchains, which are used to prove the validity of a particular state.