> ## Documentation Index
> Fetch the complete documentation index at: https://docs.snapshot.box/llms.txt
> Use this file to discover all available pages before exploring further.

# Storage proofs

Storage proofs are a way to verify data from one blockchain on another blockchain without accessing the entire state. Snapshot X collaborates with Herodotus to integrate storage proofs into its voting strategies on Starknet.

This integration allows Snapshot X to calculate voting power based on data from Ethereum mainnet or Sepolia testnet contracts. Here's how it works:

1. A block hash from Ethereum (L1) is sent to Starknet (L2)
2. Using this block hash, the state of any contract from L1 can be verified on L2 at that specific block
3. The voting strategy accesses and verifies data (like token balances) from the Ethereum contract
4. Voting power is then calculated using the verified data

This approach enables secure cross-chain governance, combining Ethereum's security with Starknet's scalability. It allows projects to use Ethereum data for voting on Starknet efficiently and securely. Currently, this feature is only available on Starknet.

### Learn more

* [Herodotus: Proving Ethereum's State Using Storage Proofs on Starknet](https://www.herodotus.dev/)
* [Storage Proofs | Herodotus Docs](https://docs.herodotus.dev/)