Imagine a world where every blockchain can connect seamlessly, regardless of its security model. Assets can flow freely across different chains, from #defi platforms to gaming ecosystems, without compromising security. That’s the future #Polygon envisions, and the launch of Pessimistic Proofs on #AggLayer Mainnet is a significant leap toward that vision.

For months, the Polygon ($POL ) community has been buzzing about AggLayer’s potential to unify multiple chains under a single bridge. But there was a challenge, how do you ensure security when different chains have varying security standards? The answer came in the form of Pessimistic Proofs.

A New Kind of Security

Picture a crowded marketplace where every vendor is selling something different. Some are seasoned traders with robust security measures, while others are newcomers with fewer safeguards. Now, imagine a security guard who treats every vendor with equal suspicion, ensuring that no one can take more than they put in.

That’s essentially how Pessimistic Proofs work. Every chain connected to AggLayer is treated as potentially risky, no matter how strong its security model is. Here’s how it functions:

  • Deposit Monitoring: Every chain’s deposits are tracked carefully. If a chain tries to withdraw more than it deposited, the system blocks the transaction.

  • Internal Accountability: Chains are required to prove that their accounting is accurate. There’s no room for double spending or false claims.

  • Cross-Chain Isolation: If one chain misbehaves, it doesn’t compromise the entire network. The problematic chain is isolated, preventing any ripple effect.

Why It Matters

Before this upgrade, only chains built with Polygon CDK could safely connect to AggLayer. But with Pessimistic Proofs now live, even chains without zero-knowledge execution proofs can connect.

Imagine a user on Chain A sending assets to Chain B, who then transfers them to Chain C to buy an NFT. Thanks to Pessimistic Proofs, every step of that transaction is scrutinized to prevent over-withdrawals. If Chain B tries to claim more assets than it deposited, the system immediately flags it. This creates a safety net that ensures all transactions are legitimate and backed by actual deposits.

What’s Next?

Polygon isn’t done yet. By the end of Q1, the AggLayer v0.3 upgrade will bring full multistack capability, allowing EVM chains to connect seamlessly. This means AggLayer will truly become stack agnostic, opening the door for more chains to join and interact without compromising security.

For the Polygon ecosystem, this is more than just a technical upgrade — it’s a promise of a more secure, interoperable, and inclusive blockchain future.

Want to learn more? Read here:

Pessimistic Proofs Live on Agglayer Mainnet https://polygon.technology/blog/major-development-upgrade-for-a-multistack-future-pessimistic-proofs-live-on-agglayer-mainnet