In Corda, what data is sent to a non-validating notary service?

问题

This question frequently comes up in conversations: When a Corda transaction is sent to a non-validating notary service for finalisation, what can the notary service see and deduce about the world?

回答1:

Before sending a transaction to a non-validating notary, it is filtered as follows:

stx.buildFilteredTransaction(Predicate { 
    it is StateRef || it is TimeWindow || it == notaryParty 
})

(see NotaryFlow.kt in the main Corda repo). This means that the non-validating notary will only see:

• Any inputs, in the form of StateRefs
• The time-window, if it exists (since the notary is also the timestamping authority)
• The identity of the transaction's notary

Because the transaction is a Merkle tree (see https://docs.corda.net/_images/merkleTree.png), although the remaining components have been removed and can't be seen by the notary, the contents of the transaction can't be changed later once the notary signature has been applied.

来源：https://stackoverflow.com/questions/47387485/in-corda-what-data-is-sent-to-a-non-validating-notary-service