Transformation in Security and Efficiency: From Reentrancy to Diamond Proxy

The security and efficiency of smart contracts are critical for both user experience and system sustainability. During pre-deployment audits, reentrancy risks and high gas costs were identified in our Solidity-based smart contracts.

The reentrancy vulnerability allowed malicious users to withdraw funds repeatedly before balances were updated due to improper sequencing of functions. This posed a significant risk of financial loss. On the performance side, inefficient data structures and unnecessary storage access increased transaction costs. In addition, the existing architecture was not modular; the risk of address changes during upgrades negatively impacted integrations and user trust.

At this point, Vinu Digital’s technical analysis clearly revealed the need for a comprehensive transformation in both security and efficiency.

Our Approach

At the start of the work, the main priority was to establish the right balance between security, performance, and sustainability. Therefore, we built the process on a three-dimensional strategy:

Security-Oriented Approach

• All function flows were reviewed and the Checks–Effects–Interactions principle was standardized.
• Critical fund transfer functions were secured with a Reentrancy Guard.
• A “pull” payment model was adopted instead of “push” to prevent chained calls in transfer flows.

Performance and Efficiency Approach

• The storage layout was redesigned; frequently used fields were grouped under a single slot to increase slot density.
• SLOAD/SSTORE operations were minimized, and repeated accesses were eliminated.
• Through data packing techniques, struct designs that previously consumed 6 slots were reduced to 4 slots, and in some cases to 3 slots.

Sustainability and Architectural Approach

• For long-term flexibility, the EIP-2535 Diamond Proxy standard was integrated.
• Contracts were divided into facets, creating a modular structure.
• During upgrades, the address was preserved, guaranteeing seamless integration for users.

With this approach, Vinu aimed not only to eliminate existing risks but also to standardize security, improve performance, and establish a long-term sustainable architecture.

Solution and Implementation

The implementation process began with closing the security vulnerability. Function flows were reorganized so that balances were updated before transfers. A pull payment model was implemented to prevent repeated withdrawals through chained calls.

On the performance side, data structures were optimized. Instead of separate slot allocation for different types, appropriate fields were grouped within the same slot to reduce storage usage. As a result, a structure consuming 6 slots was reduced to 4 slots (and in some cases, 3 slots).

On the architectural side, the Diamond Proxy integration was carried out. Functions were divided into facets, making the structure modular, and the contract address was preserved during upgrades, ensuring uninterrupted user experience. At this stage, Vinu managed the entire integration and deployment process of the solution.

Results

At the end of the implementation, the following gains were achieved:

• Security: All risks related to reentrancy were eliminated.
• Gas cost: At least 60% improvement across all transactions, and up to 90% in some functions.
• Storage efficiency: Slot usage was reduced from 6 to 4, and in some suitable cases to 3.
• Sustainability: With Diamond Proxy, a modular, upgradeable architecture was achieved, ensuring uninterrupted updates with preserved addresses.

With these results, Vinu’s solution provided full protection in security, measurable cost improvements, and seamless upgrade capability, creating strong value.

This work not only eliminated existing risks but also established a long-term sustainable architecture. Reentrancy risks were completely closed, gas costs were measurably reduced, and the user experience was preserved seamlessly.

Conclusion

As a result, Vinu Digital’s transformation has emerged as a global-scale success story, delivering:

• Full protection in security
• 60–90% cost optimization
• Seamless upgrade capability