Fhenix, a possible layer-2 community that wishes to carry absolutely homomorphic encryption (FHE) to sensible contracts, has revealed a technical white paper for the primary FHE rollup.
FHE itself is a type of encryption that ensures the confidentiality of the info even whereas it’s getting used, for instance in sensible contracts, as a result of information can stay encrypted and processed with out ever needing to be decrypted.
This allows Ethereum and different EVM networks to course of info privately, with potential purposes associated to personal voting and confidential gaming — corresponding to poker, for instance.
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In contrast to zero-knowledge (ZK) know-how, FHE is totally personal, Fhenix CEO Man Itzhaki instructed Blockworks.
“With ZK, there may be an entity known as a prover that truly sees the knowledge,” Itzhaki explains, “so confidentiality arises from the truth that this prover is being positioned on the consumer facet, producing the ZK proofs.”
One limitation is that it precludes use circumstances requiring computation on information that comes from a number of customers, he mentioned.
This isn’t the case for FHE-based techniques, Itzahki mentioned. With FHE, information and computation is completed on-chain, with out the necessity for a prover or one other entity.
“Our total imaginative and prescient at Fhenix is to create an FHE stack that can enable builders to construct purposes with information confidentiality, and for customers to profit out of those purposes by rising their stage of safety and privateness,” he mentioned.
FHE in and of itself goes past simply safeguarding privateness, Man Zyskind, the founding father of SCRT Labs (the workforce behind the Secret Community) instructed Blockworks.
“This isn’t nearly defending folks’s privateness — lack of on-chain encryption is the rationale why we’re very restricted within the purposes we will construct on blockchains right this moment. As an example, contemplate creating an on-chain poker recreation. With out encryption, gamers’ fingers can be seen to all, rendering the sport unplayable,” he mentioned.
Zyskind notes that current privacy-focused blockchains rely closely on zero-knowledge proofs, which fall quick in relation to the mixing of personal information from a number of sources, corresponding to in an on-chain poker recreation or a sealed-bid public sale contract.
“Zero-knowledge proofs are extra fitted to single-user situations, corresponding to verifying age with out revealing the precise start date. In these circumstances, zk proofs are efficient however inadequate for complicated, multi-party personal information integration, the place FHE rollups develop into important,” he mentioned.
Utilizing an optimistic rollup construction
The FHE rollup white paper outlines the usage of an optimistic rollup construction, a choice, Itzahki notes, which is able to allow the rollup to be each scalable and personal.
Though utilizing a zk rollup structure will not be solely out of the query, Itzahki explains that it might be tough to create a rollup answer that mixes two very heavy-duty cryptographic techniques.
“At present second, the implementation of FHE via optimistic [rollup structures] is rather more environment friendly,” he mentioned.
One of many key breakthroughs for Fhenix was devising an efficient mechanism for fraud proofs when utilizing an optimistic rollup.
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Itzahki explains that the workforce was capable of introduce a fraud-proof mechanism utilizing net meeting, a low-level computing language, which is able to allow fraud verification to be enacted in the identical approach as if the info was not encrypted.
“Quite than [running] on the native EVM itself, that mechanism allows us to test if that net meeting code as change, and lets us know if there’s a fraudulent transaction,” he mentioned.
Modular design
The FHE rollup will probably be designed modularly, which means that it’s going to draw from completely different parts to create the blockchain.
“We now have a separation between the sequencer, validator, and the info availability layer,” Itzahki mentioned. “The information availability layer is usually Ethereum, then we at Fhenix will deal with the sequencer and handle the execution, the validator, and the prover.”
Having a modular design will allow cryptographic improvements corresponding to FHE to execute extra effectively, enabling it to give attention to its strengths the place wanted.
“We don’t essentially must have [FHE] all through all the parts. In order that’s why we’re going with a modular design,” Itzahki provides.
Kyle Samani, managing associate at Multicoin Capital, an investor in Fhenix, mentioned the protocol’s rollup is a first-of-its-kind layer-2 that can carry FHE on-chain in a usable approach.
“The white paper is a vital first step in serving to builders notice that L2’s can be utilized for extra than simply scaling. They will now be used to increase the performance of purposes into new design areas,” Samani mentioned.
Fhenix plans to launch the testnet of its first FHE rollup within the first quarter of 2024. It’s undecided whether or not the rollup stack will probably be constructed open-source, although testing will probably be accessible to any initiatives.