Announcement Validation

DSNP Announcements on Ethereum are validated at read time.

1. Read DSNPBatchPublication events.
2. Fetch and validate the Batch Publication.
3. Validate the chain of delegation from the Announcement's fromId to the sender of the transaction with the DSNPBatchPublication event.

Batch Publication Validation

1. Hash the batch publication file using keccak-256.
2. Retrieve the published hash for the given file from the DSNPBatchPublication Event.
3. The file hash MUST match the retrieved hash from the DSNPBatchPublication event.

Announcement Validation

1. Get the Ethereum address of the sender for the transaction from the Batch (aka the Batch Publisher).
2. Find the Identity Contract for the Announcement's fromId.
3. Test the Batch Publisher's Ethereum address against the Identity Contract via IDelegation.isAuthorizedTo with the permission ANNOUNCE and the block number from the DSNPBatchPublication event.

Announcement Duplicates

Duplicate Announcements MUST be rejected or ignored.