CorDapp Identities

Parties on the network are represented using the AbstractParty class. There are two types of AbstractParty:

• Party, identified by a PublicKey and a CordaX500Name
• AnonymousParty, identified by a PublicKey only

Using AnonymousParty to identify parties in states and commands prevents nodes from learning the identities of the parties involved in a transaction when they verify the transaction’s dependency chain. When preserving the anonymity of each party is not required (e.g. for internal processing), Party can be used instead.

The identity service allows flows to resolve AnonymousParty to Party, but only if the anonymous party’s identity has already been registered with the node (typically handled by SwapIdentitiesFlow or IdentitySyncFlow, discussed below).

Party names use the CordaX500Name data class, which enforces the structure of names within Corda, as well as ensuring a consistent rendering of the names in plain text.

Support for both Party and AnonymousParty classes in Corda enables sophisticated selective disclosure of identity information. For example, it is possible to construct a transaction using an AnonymousParty (so nobody can learn of your involvement by inspection of the transaction), yet prove to specific counterparts that this AnonymousParty actually corresponds to your well-known identity. This is achieved using the PartyAndCertificate data class, which contains the X.509 certificate path proving that a given AnonymousParty corresponds to a given Party. Each PartyAndCertificate can be propagated to counterparties on a need-to-know basis.

The PartyAndCertificate class is also used by the network map service to represent well-known identities, with the certificate path proving the certificate was issued by the doorman service.