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# System prepended metadata

title: Lumia L2 - Fork ID 12 Release Notes

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# Lumia L2 - Fork ID 12 Release Notes

## Overview

We're excited to announce the upgrade of Lumia L2 to [Fork ID 12](https://github.com/0xPolygonHermez/cdk-erigon/releases/tag/v2.61.17), powered by the @0xPolygon CDK stack! 🚀

This upgrade introduces several key features designed to enhance the security, reliability, and interoperability of the Lumia L2 blockchain ecosystem. The improvements focus on transaction reliability, cross-chain security, and network resilience.

## Key Features

### 🔹 ZK Counters
- Transactions will now have a higher success rate with additional counters
- Improved handling of counter overflow conditions during gas estimation
- Enhanced reliability for transaction processing

### 🔹 Pessimistic Proofs (Coming Soon)
- An innovative feature providing an additional cryptographic layer of cross-chain security
- Assumes every connected chain could be unreliable, ensuring that one chain's issues cannot compromise the unified bridge
- Designed to strengthen cross-chain asset transfers while prioritizing the safety of funds across the network 🔒

### 🔹 Rollback Sequences & Special Recovery Mode
- Introduces rollback sequences and a special recovery mode
- Makes the network even more reliable by allowing for safer transaction management
- Provides recovery capabilities in case of issues
- Enhances overall network stability

## Technical Improvements

### Bug Fixes
- fix(counters): smt depth fix and test ([#1695](https://github.com/IvanBelyakoff) in [#1751](https://github.com/))
- fix: nil crash on uninitialized block var ([#1763](https://github.com/) by @IvanBelyakoff)
- fix: unreadable symbols in DS stream on client side ([#1750](https://github.com/) by @IvanBelyakoff)
- fix(rpc): stop getblockhash from crashing when sending hash ([#1761](https://github.com/) by @elliothllm in [#1771](https://github.com/))
- Fix/estimateGas ignores counters if disable-virtual-counters=true ([#1799](https://github.com/) by @IvanBelyakoff)

### Enhancements
- tweak(witness-cache): cache offset before and after ([#1768](https://github.com/) by @elliothllm)
- improve(smt/pkg/utils): improve the performance of HashContractByteco... ([#1780](https://github.com/) by @revitteth)
- feat(gas-price-tolerance): add gas-price-tolenrance flag [stable] ([#1781](https://github.com/) by @revitteth)
- feat: check counters overflow on eth_estimateGas ([#1794](https://github.com/) by @IvanBelyakoff)

## Future Roadmap

This upgrade lays the groundwork for several exciting future improvements:
- 250ms block speeds
- Increased TPS (Transactions Per Second)
- Elastic block generation
- Additional performance and security enhancements