Unlocking Production Blockchain with Paladin: Programmable Privacy for EVM | Digital Euro Conference

Summary

In this presentation, Javier Garcia, Global Lead of Digital Assets at Kaleido, discusses Paladin, an open-source privacy solution for the Ethereum Virtual Machine (EVM) space. He highlights its role in enabling privacy for blockchain transactions, particularly in the financial sector. Using the Guardian Wholesale Network and a UK-Ireland hackathon project as case studies, Javier demonstrates how Paladin ensures private, composable transactions in multi-party networks. He emphasizes the importance of protecting both on-chain and off-chain data and how Paladin offers an end-to-end infrastructure for secure, privacy-enhanced financial workflows.

Takeaways

• 😀 Paladin is an open-source solution designed to provide privacy in the blockchain ecosystem, specifically for financial institutions.
• 😀 Paladin supports privacy not just for on-chain transactions but also for off-chain workflows and data exchanges.
• 😀 The solution was demonstrated successfully in the Guardian Wholesale Network (GWN) project in Singapore, focusing on multi-asset and multi-currency transactions.
• 😀 In the GWN, Paladin enabled private transactions, particularly for fixed-income products like bonds, where sensitive data like amounts and identities were hidden from unauthorized participants.
• 😀 Paladin ensures end-to-end privacy by providing tools like a transaction manager, indexer, and private databases for secure data handling.
• 😀 A significant part of the solution involves secure off-chain communication, using transport layers like NTLS to send private data between participants.
• 😀 Paladin integrates zero-knowledge proofs (ZKPs) to ensure privacy for on-chain data, allowing for secure verification without revealing sensitive details.
• 😀 In the UK-Ireland Hackathon, Paladin demonstrated private transactions between two blockchain networks, ensuring the privacy of tokenized assets like bonds.
• 😀 Paladin's features are compatible with the Ethereum Virtual Machine (EVM) ecosystem, allowing easy integration with existing blockchain networks and applications.
• 😀 Paladin is part of an open-source project hosted under the Linux Foundation, making it publicly available for collaboration and further development.

Q & A

What is the main focus of Javier Garcia’s presentation?

Javier Garcia’s presentation focuses on demonstrating how Kaleido’s open-source product, Paladin, enables privacy in blockchain-based digital asset networks, particularly within enterprise and financial institutions.

What is Paladin, and who developed it?

Paladin is a privacy solution for Ethereum Virtual Machine (EVM)-based blockchains developed by Kaleido. It ensures transaction confidentiality by allowing only authorized participants to view sensitive data while maintaining interoperability across networks.

In which event was Paladin open-sourced, and under what foundation?

Paladin was open-sourced in November during the Singapore Fintech Festival under the Linux Foundation Decentralized Trust (previously called the Hyperledger Foundation).

What is the Guardian Wholesale Network (GWN), and what was its main purpose?

The Guardian Wholesale Network is a multi-member, multi-asset, and multi-currency blockchain test network created under Singapore’s Project Guardian framework, regulated by the Monetary Authority of Singapore (MAS). Its purpose was to enable cross-use case composability and interoperability between different financial products and participants.

Which financial institutions participated in the Guardian Wholesale Network project?

Participants included major financial institutions such as HSBC, Standard Chartered, Citi, Schroders, and UOB, along with the Monetary Authority of Singapore as an observer.

Why was privacy a key requirement in the Guardian Wholesale Network?

Privacy was essential because each member had its own node and could otherwise see all on-chain transactions. Paladin ensured that sensitive information, such as bond transaction details or payment amounts, was only visible to authorized participants involved in each specific transaction.

How does Paladin provide privacy for blockchain transactions?

Paladin uses a privacy ledger and a UTXO-based model to store states instead of exposing all transaction details publicly. It allows only participants in a transaction to see relevant data such as transaction amounts, sender and receiver information, and ownership records, ensuring a need-to-know basis for data visibility.

What was the role of Paladin in the UK-Ireland hackathon project?

In the UK-Ireland hackathon, Paladin was used to demonstrate private transactions on an EVM-based network integrated with the UK Regulated Liability Network (RLN). It showcased how privacy-preserving bonds could interact with the RLN’s tokenized deposit system through secure interoperability mechanisms.

What technologies or mechanisms were used to ensure secure interoperability between networks in the hackathon?

The interoperability between the Paladin-based EVM network and the RLN infrastructure was achieved using escrow or Hash Time-Locked Contracts (HTLCs) to coordinate secure and atomic transactions between different blockchains.

How does Paladin handle user and off-chain data privacy?

Paladin manages both on-chain and off-chain privacy through an end-to-end framework. It includes a private database for user data, a transaction manager, secure transport layers for inter-party data exchange, and a wallet capable of generating zero-knowledge proofs.

What types of financial products were tested within the Guardian Wholesale Network using Paladin?

The tested products included tokenized cash, FX assets, bonds, repos, and money market funds. The focus was on demonstrating life-cycle management, secondary markets, dividend payments, and private zero-coupon bond transactions.

What was the main takeaway from the presentation regarding privacy in blockchain systems?

The main takeaway is that true privacy in blockchain systems requires more than on-chain encryption; it also involves managing privacy across workflows, participants, and off-chain data through an integrated approach like Paladin’s.