Data privacy and Encryption

Auxledger ecosystem aims to enable enterprise blockchain solutions where data privacy is of utmost importance. Here we are proposing a tested framework enhanced upon the usability of Auxledger ecosystem. Auxledger privacy component rides upon a combination of 2 models – (i) Enigma based decentralize computation platform, and (ii) Hawk model for privacy preserving smart contracts.

Using Enigma’s secure multi-party computation [7] (sMPC or MPC), data queries are computed in a distributed way, without a trusted third party. Data is split between different nodes, and they compute functions together without leaking information to other nodes. Specifically, no single party ever has access to data in its entirety; instead, every party has a meaningless (i.e., seemingly random) piece of it.

To maximize the computational power of the network, we introduce a network reduction technique, where a random subset of the entire network is selected to perform a computation. The random process preferentially selects nodes based on load-balancing requirements and accumulated reputation, as is measured by their publicly validated actions. This ensures that the network is fully utilized at any given point.

Another component of Auxnet privacy remains in portion of privacy preserving smart contract. The onchain privacy and contractual security is based upon Hawk model [8]. On-chain privacy stipulates that transactional privacy be provided against the public (i.e., against any party not involved in the contract) – unless the contractual parties themselves voluntarily disclose information. Although in Hawk protocols, users exchange data with the blockchain, and rely on it to ensure fairness against aborts, the flow of money and amount transacted in the private Hawk program is cryptographically hidden from the public’s view. Informally, this is achieved by sending “encrypted” information to the blockchain and relying on zero knowledge proofs to enforce the correctness of contract execution and money conservation.

While on-chain privacy protects contractual parties’ privacy against the public (i.e., parties not involved in the financial contract), contractual security protects parties in the same contractual agreement from each other. Hawk assumes that contractual parties act selfishly to maximize their own financial interest. In particular, they can arbitrarily deviate from the prescribed protocol or even abort prematurely. Therefore, contractual security is a multi-faceted notion that encompasses not only cryptographic notions of confidentiality and authenticity, but also financial fairness in the presence of cheating and aborting behavior.

[7] A. Kosba, A. Miller, E. Shi, Z. Wen and C. Papamanthou, “Hawk: The Blockchain Model of Cryptography and
Privacy-Preserving Smart Contracts” 2016.

[8] G. Zyskind, O. Nathan and A. Pentland, “Enigma: Decentralized Computation Platform with Guaranteed Privacy” 2015.

Was this article helpful?