IZAR: The Future of Cross-chain Privacy

4 min readJun 2, 2023

Today, we are very excited to introduce IZAR, our solution to serve and support applications that require cross-chain privacy from Aleo. IZAR is essentially an abbreviation for Interoperability Zero-Knowledge Anonymous Relays, which obviously aims to bring interoperability across different blockchains while ensuring privacy and anonymity in a secure and reliable manner.

What type of bridge is IZAR?

The given table is 3 major categories of cross-chain bridges, and clearly, there is no single category that optimizes for security, decentralization, and heterogeneous blockchain support. External bridges sacrifice decentralization and security to some extent for wider interoperability while native bridges do the opposite. Local bridges cannot scale to many blockchain connections. IZAR is close to the External bridge, however, we are making it more resilient with a little different design.

The ideal cross-chain bridge would fuse the strengths of the different categories. It would provide a decentralized and trust-minimized bridging mechanism, support heterogeneous blockchain interoperability, and have a scalable architecture. Such a bridge could help realize the vision of a truly open, connected, and secure decentralized ecosystem, which is what IZAR aims to achieve.

Why bridging Aleo?

Cross-chain bridges serve as an essential lifeline between isolated blockchain networks, fostering collaboration and innovation by enabling the exchange of information and value across diverse ecosystems. Aleo, as the first L1 blockchain to support full on-chain privacy, can greatly benefit from bridging to other networks, given its novel platform and need for broader integration. When highlighting the importance of bridging Aleo to other networks, consider the following key points:

Enhanced Privacy-Preserving Asset Transfers: By connecting Aleo to other networks, users can seamlessly move assets between various blockchain platforms while maintaining privacy. This not only increases liquidity but also encourages a more inclusive ecosystem where privacy is prioritized.

Interoperability for Privacy-focused Applications: Cross-chain bridges facilitate seamless communication between Aleo and other blockchain networks, opening the door for the development of more sophisticated and interconnected privacy-centric applications. This enables developers to leverage Aleo’s unique privacy features and collaborate with projects on other networks, spurring innovation in the blockchain space.

Decentralization and Resilience: Bridging Aleo to multiple blockchain networks helps distribute power and control, fostering a more decentralized and resilient ecosystem. By connecting with a diverse range of networks, Aleo can mitigate the risks associated with reliance on a single platform, ensuring robustness and long-term sustainability.

Access to New Markets and Opportunities: Bridging Aleo to other networks enables it to tap into new markets and opportunities, bolstering its growth and adoption. As the platform becomes more open and compatible with other ecosystems, it can attract a wider range of users, developers, and partners, ultimately contributing to its success.

What are the current obstacles?

Cross-chain technology has allowed for free flow of assets, but it has also introduced some issues such as over-centralization, control by a few key individuals, smart contract risks, asset tracking,asset transparency, and a lack of external oversight. This is due to the enormous amount of traffic and assets attracted by leading applications, making them vulnerable to hacking attacks and user data breaches. As a result, there is a need for better security measures and external oversight to ensure the safe and efficient operation of decentralized applications and cross-chain infrastructure.

Our Solution

To tackle the challenges around cross-chain asset transfers, the IZAR protocol aims to enable arbitrary message-based cross-chain transactions while solving key problems related to asset security, privacy protection, and decentralization. The IZAR protocol consists of two main layers:

Governance: Decentralization, Openness, and Security

Some cross-chain bridges are not as decentralized in terms of cross-chain asset validation. They primarily rely on multi-signature schemes involving a few individuals or third-party guarantees, which introduce single points of failure and potential centralized risks. Our validation approach focuses on selecting influential members from the global community through a Proof of Authority (PoA) mechanism, gradually expanding the number of participants to achieve decentralization. Additionally, threshold signatures ensure that 2/3 of the participants can complete the validation. The key aspects of this approach include members with credibility, a sufficient number of nodes, and partial signatures generating complete signatures to ensure trustworthy governance.

Privacy Protection

Tornado Cash serves as an example for building a zk cross-chain bridge to achieve private asset transactions. The system utilizes multiple pools, each holding ETH deposits and withdrawals with fixed amounts. This design segregates user transactions, enhancing privacy and security by preventing external parties from linking depositors and withdrawers in the same pool. Consequently, third-party observers can only identify that a withdrawer’s account is one of N interacting accounts.

In contrast, on the Aleo network, all data remains anonymous and untraceable, eliminating the need for multiple pools. A large aggregated privacy pool can effectively increase the denominator and better achieve privacy protection. However, it’s essential to recognize that this solution is still under development and refinement.

We are diligently working on our development efforts and believe that Aleo will bring transformative changes to the blockchain industry with privacy-preserving smart contracts. We are confident that, in the near future, Web3 will gradually move towards decentralization and privacy, filling the final missing piece in the puzzle.

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