Quantum Attacks on Web3: Using multiple blockchains as "crosswitnesses" to make the attack economically unviable.

There is a lot of talk about "Q-Day" and how quantum computing will break algorithms like ECDSA (used in Ethereum, Polygon, etc.). The obvious solution is to migrate to post-quantum firms, but while that transition is happening, I've been designing a conceptual architecture for oracles that repels attack using pure logistics and economic security.

I would like to know what the community thinks about this approach.

The Problem: The Single Point of Failure

If a data oracle relies on a single blockchain, a quantum attacker breaking that specific network can forge a signature and alter a smart contract. To the oracle, that lie will seem like a cryptographic truth.

The Proposed Solution: Cross-Chain Witnessing

Instead of relying on a single network, the system emits the same data hash simultaneously to multiple independent networks (e.g. Ethereum, Arbitrum, Optimism, Polygon).

When the oracle needs to validate the information, it consults all networks at once.

Why this neutralizes the attack:

We often assume that a quantum attacker has endless resources. The reality is that scaling a quantum computer is expensive.

To deceive this multi-chain oracle, the attacker cannot break a single network. He would have to coordinate and execute a simultaneous quantum attack on 4 or 5 totally different consensus infrastructures, in the same block window, so that they all return the same lie at the same time.

If the attacker only manages to alter one network, the oracle detects a mismatch with the other chains and automatically blocks the operation.

Basically, we multiply the cost and complexity of the attack exponentially, moving from a mathematical problem (breaking a key) to an almost impossible logistical/economic problem.

Also, if you add to this a strict layer of defense on the oracle's own server (ephemeral stateless authentication) to filter out bots before they touch the blockchain, the attack vector is drastically reduced.

Does this architecture make sense as a layer of temporary redundancy? At the "Economic Security" level, do you think the cost of synchronizing a multi-chain quantum attack is enough to deter attackers?