In an interview with Cointelegraph at the Stanford Blockchain Conference on February 19, the PhD in cryptography from Stanford University. Student Ben Fisch described Supersonic as a knowledgeless and trustless proof system, also known as zk-SNARK.
Fisch helped create a knowledgeless and trustless proof system designed specifically for decentralized finance.
Zk-SNARK without trust against trust
While zero-knowledge proof systems are needed to maintain privacy on blockchain networks, almost all of them require trust configurations. Fisch said: “This means that users of the privacy tool have to trust a third party to properly configure the system.”
For example, privacy-focused digital currency Zcash (ZEC) leverages zk-SNARKs to allow users to exchange information without revealing their identity. This means that Zcash’s blockchain only shows which transactions took place, rather than who was involved and what amounts were exchanged.
While this ensures the privacy and transparency of Zcash’s blockchain network, Fisch noted that Zcash relies on a zk-SNARK trust setup called Groth-16. He explained that trust configurations such as this could compromise public trust in a system:
“In particular, zero-knowledge proof systems involve randomly generated numbers. Trusted configurations mean that the third party must be trusted to properly generate these numbers and keep them secret (i.e. reject secrets and destroy all traces so that no one finds out in the future). If the secrets are disclosed, the security of the zero-knowledge evidence system is compromised. ”
Fisch further noted that trust can be distributed across a collaborative committee in trust configuration systems. This means that as long as a party correctly rejects its own secrets, the system can be considered secure.
Although this was done repeatedly through collaborative “ceremonies,” Fisch said it was impractical to do this again for every new application requiring a zk-SNARK. “This is understandable because before this last year there was no practical universal setup or zk-SNARK trustless setup.”
Stanford PhD student Benedikt Bünz, who co-wrote an article on cryptography and cryptocurrencies with Fisch, told Cointelegraph that unlike trusted configuration systems, Supersonic does not require any third-party trust. . Bünz explained:
“In a trusted configuration, the person (or persons) doing this can prove that an invalid transaction is valid. In a cryptocurrency this could be used to create money out of thin air. Previous proofs without a trust configuration were either in the hundreds of kilobytes or did not have the scalability property.
zk-SNARK without trust for DeFi
According to Fisch, a trustless zk-SNARK like Supersonic is a major breakthrough in crypto over the past year, especially as decentralized financial applications gain traction. Fisch explained that while the blockchain promises to make financial systems more open and transparent in order to prevent Ponzi schemes and fraudulent activity, privacy is often completely destroyed.
Fisch noted that Findora, the company behind Supersonic, primarily targets financial use cases to bring decentralization and transparency to businesses that need privacy, such as banks. He said:
“Many businesses can immediately benefit from blockchain without decentralization, but there is an advantage in having a decentralized and reliable financial network that can connect services and people using the same infrastructure.”
For example, Fisch noted that a China-US-based peer-to-peer lending system could run on Findora’s blockchain. He explained that commerce could work between the two systems with a consensus protocol that facilitates the use of both networks while Supersonic guarantees trust.
However, it is important to stress that trusted configuration systems are not as efficient as untrusted configuration systems. Fisch said Supersonic performs around 10 times lower than trusted configuration systems, both in test size and compute time.
Indeed, one of the key components of Supersonic is a cryptographic tool called “Group of unknown order”. Fisch added that a new GUO was announced recently, adding that “if we use this new GUO tool instead of the one we are currently using, it will reduce the performance gap in terms of size and time.”
Regardless of his current performance, Bünz mentioned that Supersonic has caused a stir in upcoming DeFi projects like ETH 2.0, noting that the underlying tool used in Supersonic is the same as in the verifiable delay functions:
“VDFs are a cryptographic tool that can be used to create perfect randomness, which is necessary for proof-of-stake networks. VDFs will be used in ETH 2.0. There is already a lot of investment in building good hardware and software support for VDFs.
Recently, Ethereum co-founder Vitalik Buterin has drawn more attention to privacy solutions. When asked about Supersonic, Buterin told Cointelegraph that “Supersonic is a very good solution for the problem he is trying to solve.”