Decentralized Confidential Payment System with Auditability, PGC Accepted for ESORICS 2020
Creators of Decentralized Confidential Payment System with Auditibility better known as PGC, Yu Chen, Xuecheng Ma, Cong Tang, and Man Ho Au have landed a great opportunity to present their Ethereum-based project at ESORICS 2020.
The European Symposium on Research in Computer Security (ESORICS) is organized by the University of Surrey, and this year the 25th leg of the Symposium will be held in Guildford, United Kingdom from September 14–18, 2020.
This is a significant achievement for PGC as the project’s document is amongst 72 papers screened from a total of 366 submissions. The selection process was tough as every submission was thoroughly perused by 3–5 referees and then discussed within the Program Committee.
PGC with submission number 195 made it to the presentation round after 4 review sessions. Let’s examine what the journey was like:
Review 1
In the first review, the basic structure of the project was discussed. The basic objective of the project — the establishment of a blockchain-based payment system through a middle-of-the-road approach between anonymity and auditability was acknowledged.
In the evaluation, PGC’s construction was discussed in great detail. The twisted ElGamal encryption scheme introduced in the paper was found to be a ‘part of the integrated signature and encryption scheme (ISE) where users have a single key pair for signing/encryption operations.’
According to the reviewers, PGC has been developed at par with decentralized and confidential payment protocols that provide an alternative method for combining Sigma proofs with Bulletproofs.
Overall the paper was found to be well-researched and well-written.
Review 2
The second review process saw the examining committee understand the point of view and objective of PGC creators. The reviewers acknowledged the confidentiality roadblocks in public blockchains like Bitcoin and Ethereum.
Also, they understood how things can go wrong privacy and confidentiality is beefed up in digital currency systems. And how ‘compliance with auditability’ can serve a better purpose.
The Program Committee found certain strengths related to the project. The structure and framework were adequate. The encryption scheme was explained in ‘sufficient detail’.
Review 3
Review 3 too pointed out how the PGC team recognized confidentially issues in current blockchain-based payment systems. The reviewers appreciated the proposal to improvise confidentiality in decentralized transactions through the introduction of auditability without foregoing anonymity.
The solution was found to be intuitive and the confidential but auditable payment system approach was found to be efficient. Also, the structure of the article was found to be good.
There were some improvements suggested, however. The Program Committee suggested adding figures to explain ‘the interaction between actors’. Authors Yu Chen, Xuecheng Ma, Cong Tang, and Man Ho Au were also advised to talk about KYC and AML regulations.
Review 4
In the fourth and final review, the Program Committee was impressed by the notion of a decentralized confidential payment (DCP) system with auditability. The committee also found PGC as ‘an efficient instantiation and implementation of the generic construction’.
To quote the exact words from the review:
This paper introduces and formalizes the notion of auditable DCP system, which is of great interest in real-world blockchain-based applications that require regulation compliance. A generic construction of auditable DCP is given with clean and rigorous security proof. Towards an efficient instantiation of auditable DCP, a novel homomorphic PKE called twisted ElGamal is newly introduced. Twisted ElGamal is of great interest on itself as a homomorphic PKE. The authors attempt to show an implementation of twisted ElGamal. In the optimization part, the authors should show how to eliminate the explicit use of signature by careful weakening the security definition of DCP and reusing the zero-knowledge proofs for well-formedness of transactions. This optimization trick may be useful in other applications that require both signature and zero-knowledge proofs.
Through the aforementioned rigorous review procedures, the PGC team made it to ESORICS 2020. It is a great instance of achievement for the project. This is just the beginning. Much more amazing and ‘pretty good’ things await PGC.
