...by Daniel Szego
"On a long enough timeline we will all become Satoshi Nakamoto.."
Daniel Szego

Sunday, March 19, 2023

zkSNARK aritmetic circuit


An arithmetic circuit is a type of digital circuit that performs arithmetic operations, such as addition, subtraction, multiplication, and division, on binary numbers. It typically consists of digital logic gates, such as AND, OR, NOT, and XOR gates, which are interconnected to implement the desired arithmetic operation.

Arithmetic circuits are widely used in digital electronics and computer systems, where they form the basic building blocks for performing mathematical computations. They are used in a variety of applications, such as signal processing, image processing, cryptography, and data compression.

Arithmetic circuits can be implemented using various technologies, such as discrete logic gates, programmable logic devices (PLDs), and application-specific integrated circuits (ASICs). The choice of technology depends on factors such as performance, cost, power consumption, and design complexity.

Arithmetic circuits are commonly used in zero-knowledge proofs (ZKPs) as a way to prove knowledge of a secret value or computation without revealing any information about the value or computation itself.

In a ZKP protocol that uses arithmetic circuits, the prover constructs a circuit that performs some computation on secret inputs, and then generates a proof that convinces the verifier that the computation was performed correctly, without revealing any information about the inputs. The verifier checks the proof by evaluating the circuit on some public inputs and verifying that the output matches the claimed result.

Arithmetic circuits are particularly useful for ZKP protocols because they can be efficiently evaluated using existing hardware and software tools, and can be easily integrated with other cryptographic primitives. They also allow for complex computations to be performed in a way that preserves privacy, making them well-suited for applications such as authentication, voting, and blockchain technology.

One example of an arithmetic circuit used in a ZKP protocol is the circuit used in the Bulletproofs protocol, which is used to prove that a committed value lies within a certain range. The circuit is constructed in such a way that it can be efficiently evaluated using existing hardware and software tools, and allows for a highly efficient and secure range proof.