INTMAXINTMAX

Description

INTMAX proverAn entity that generates the cryptographic proof to convince the verifier that the statement is true. In a ZK-Rollup, the prover generates the ZK (validity) proof to submit to the verifier contract. is a zk proving system for privacy-preserving INTMAX L2Layer 2 (L2) is a category of technical solutions aimed to scale the base layer in a trust minimized way. This category includes solutions like rollups as well as state channels and plasma. Other solutions are able to scale further, but with the introduction of additional trust assumptions, which are therefore not trust minimized. Sometimes the term Layer 2 is used to refer to include these solutions too, like validiums and optimiums, but to distinguish between trust minimized and non trust minimized solutions they are often referred to as "light" L2s, opposed to "strong" L2s like rollups. based on Plonky2 circuits, optimized for clientSometimes labelled interchangeably as a “node”, they are tasked with processing transactions and managing the blockchains's state. They run the computations for each transaction according to the rollup's virtual machine and protocol rules. If comparing to Ethereum clients, these would be execution clients such as Geth, as opposed to consensus clients. side proving and using not only succinctnessA property of ZKP that stands for the following terms: (i) the proof of statement is shorter than the statement itself, (ii) the time to verify the proof is faster than just to evaluate the function from scratch., but also zero knowledge properties of Plonky2. INTMAX circuits are proven with a STARKShort for "scalable transparent argument of knowledge", a STARK is a type of zero-knowledge proof that resolves one of the primary weaknesses of ZK-SNARKs, its reliance on a "trusted setup”. STARKs also come with much simpler cryptographic assumptions, avoiding the need for elliptic curves, pairings, and the knowledge-of-exponent assumption and instead relying purely on hashes and information theory. This means that they are secure even against attackers with quantum computers. which is wrapped into a PlonkA zk-SNARK proving system introduced by Gabizon, Williamson and Ciobotaru in 2019 that allows proving custom circuits. Plonk is based on KZG polynomial commitments and thus requires a universal trusted setup. SNARKShort for "succinct non-interactive argument of knowledge", a SNARK is a widely used type of zero-knowledge proof that is short and fast to verify. Different kinds of SNARKs are usually systematized by proof size, verification time, and type of setup. The most famous SNARKs are Groth16, PLONK/Marlin, Bulletproofs, and STARKs. before settling onchain.

Proof systemThe infrastructure that allows projects to verify their state transitions. It is composed by onchain verifiers and offchain provers. The main two flavors are optimistic and ZK proof systems, but they can be combined in a hybrid model. In general though, if a system is able to accept state roots optimistically, even if it has a ZK component, it is considered an optimistic proof system.

Plonky2 implements a circuitA program written for the purpose of being proven within a proving system. A circuit is a mathematical representation of the computation to be executed, arithmetic circuits and zkVM execution trace are examples of circuits. Circuits can be written in different languages, ranging from low-level to high-level. aritmetization based on TurboPlonk over Goldilocks field, but it replaces KZGA polynomial commitment scheme that allows a prover to compute a commitment to a polynomial, with the properties that this commitment can later be opened at any position: the prover shows that the value of the polynomial at a certain position is equal to a claimed value. KZG is widely used as it’s applicable both for univariate and k-variate polynomials, is efficient for batch proofs, and is able to generate many proofs at once relatively fast. It is also proof generation time efficient: the time for prover to commit to a polynomial is linear on the degree of the polynomial. polynomial commitmentA commitment scheme that commits to a polynomial and allows generating the proof of opening the polynomial at a given point against the commitment. scheme with a FRIA proximity test method that is used to determine whether a set of points is mostly on a polynomial with a degree less than a specified value. It resembles the FFT but the arithmetic complexity of its prover is strictly linear and that of the verifier is strictly logarithmic.-based polynomial testing scheme. In this way proving Plonky2 circuits requires no trusted setupGeneration of a piece of data that must then be used for some cryptographic protocol to run. Generating this data requires some secret information. The "trust" comes from the fact the secret must be destroyed after the ceremony, otherwise cryptographic properties of the protocol could be broken. Once the data is generated, and the secrets are forgotten, no further participation from the creators of the ceremony is required. There are two types of trusted setups for SNARKs: (i) trusted setup per circuit where it is generated from scratch for each circuit, (ii) trusted universal setup per proving system where it can be used for several circuits., i.e. it is a STARK. However the circuit design is different from zkVMA special type of zk proving system that proves the correctness of state transitions of a virtual machine. Computation is represented by a program in a specific instruction language, it can have private and public inputs and public outputs. Most of zkVMs are STARKs. STARKs, so INTMAX custom logic is implemented as custom circuits rather than a zkVM program.

Circuits

INTMAX prover works with several different circuits that could be proven by different entities in the networkA constellation of nodes (peers) that communicate via a peer-to-peer protocol, for example, in propagating transactions and blocks to other nodes. (e.g. users, validity provers, aggregators). This design support local proving and enables private transactions on the L2.

Available circuits are: validity for proving public state transition, balance for proving correct updates of individual user accounts based on private information, withdrawal for proving the validity of withdrawing funds from L2 to the host chain, claim for proving user eligibility for privacy mining program and proof of innocence for proving certain claims about deposits and withdrawals.

Recursion and final wrap

INTMAX circuits are based on recursive architecture, where generating a new STARK requires validating a previous STARK proof (e.g. processing a new balance update requires validating all previous balance updates). Several entities are responsible for providing these recursive proofs: users or balance provers for balance updates, validity provers for validity circuit, claim and withdrawal aggregators for processing claim and withdrawal proofs.

Only claim and withdrawal proofs are posted onchain to be verified, all other proofs are verified only by the nodes in INTMAX network. Onchain proofs are wrapped in a gnark implementation of Plonk over BN254 curve, which requires a trusted setup (see below for more details).