Broadcast / shared data
Multi-party systems are about establishing a shared source of truth, and often that needs to include certain reference data that is available to all parties in the network. The data needs to be “broadcast” to all members, and also need to be available to new members that join the network
Blockchain backed broadcast
In order to maintain a complete history of all broadcast data for new members joining the network, FireFly uses the blockchain to sequence the broadcasts with pinning transactions referring to the data itself.
Using the blockchain also gives a global order of events for these broadcasts, which allows them to be processed by each member in a way that allows them to derive the same result - even though the processing logic on the events themselves is being performed independently by each member.
For more information see Multiparty Event Sequencing.
The data included in broadcasts is not recorded on the blockchain. Instead a pluggable shared storage mechanism is used to contain the data itself. The on-chain transaction just contains a hash of the data that is stored off-chain.
This is because the data itself might be too large to be efficiently stored and transferred via the blockchain itself, or subject to deletion at some point in the future through agreement by the members in the network.
While the data should be reliably stored with visibility to all members of the network, the data can still be secured from leakage outside of the network.
The InterPlanetary File System (IPFS) is an example of a distributed technology for peer-to-peer storage and distribution of such data in a decentralized multi-party system. It provides secure connectivity between a number of nodes, combined with a decentralized index of data that is available, and native use of hashes within the technology as the way to reference data by content.
FireFly built-in broadcasts
FireFly uses the broadcast mechanism internally to distribute key information to all parties in the network:
- Network map
- Organizational identities
- See Identities in the reference section for more information
- Datatype definitions
- See Datatype in the reference section for more information
- See Namespaces for more information
These definitions rely on the same assurances provided by blockchain backed broadcast that FireFly applications do.
- Verification of the identity of the party in the network that performed the broadcast
- Deterministic assignment of a namespace+name to an unique item of data
- If two parties in the network broadcast the same data at similar times, the same one “wins” for all parties in the network (including the broadcaster)