[gus_massa]

Is the data in the blockchain?

[Qniwwwerss]

Yes, the most sensitive data will be stored in the blockchain.

[gus_massa]

And how do you revoque authorizatio to read it?

[Qniwwwerss]

We can simply remove that identity from list, so it will not be able to read or write. I think we can also change permissions, to restrict reading/writing.