NECTAR: Non-Interactive Smart Contract Protocol using Blockchain Technology

TL;DR

NECTAR introduces a blockchain protocol that executes smart contracts within transaction validation, ensuring privacy, correctness, and verifiability without requiring participant communication or re-execution by all nodes.

Contribution

The paper presents a novel non-interactive smart contract protocol that enhances privacy and efficiency while maintaining security and verifiability on blockchain platforms.

Findings

Prevents man-in-the-middle attacks

Reduces re-execution of smart contracts across nodes

Optimizes execution time and memory usage

Abstract

Blockchain-driven technologies are considered disruptive because of the availability of dis-intermediated, censorship-resistant and tamper-proof digital platforms of distributed trust. Among these technologies, smart contract platforms have the potential to take over functions usually done by intermediaries like banks, escrow or legal services. In this paper, we introduce a novel protocol aiming to execute smart contracts as part of a blockchain transaction validation. We enable extensions in the execution of smart contracts while guaranteeing their privacy, correctness and verifiability. Man-in-the-middle attacks are prevented, since no communication between participants is requested, and contract validations do not imply the re-execution of the code by all the nodes in the network. However, proofs of correct execution are stored on the blockchain and can be verified by multiple parties. Our solution is based on programming tools which optimize the time execution and the required memory while preserving the embedded functionality.