Ethereum how to re-encrypt the sensitive data if the private key leaks

Question

Assuming some sensitive data is encrypted by the public key and stored on the ethereum network.

My question is: If the private key leaks, can we re-encrypt the data so that the data cannot be decrypted by the leaked private key?

Since the immutability of the blockchain, I thinks it's impossbile, right?

Are there any other good solutions for storing the sensitive data?

Answer 1

If the private key leaks, can we re-encrypt the data so that the data cannot be decrypted by the leaked private key?

You could reencrypt the data with a new private key, and write that new encrypted data to the blockchain. However, since ethereum maintains a complete historical state, your previous version of the data will still be visible in the past blocks, allowing anyone to decrypt it.

Are there any other good solutions for storing the sensitive data?

Encrypt and store the data off chain, and just publish a hash of the data to the chain for integrity/security checks/proof of time.