Entropy

[Source]

(Added by the RNG amendment.)

An Entropy pseudo-transaction carries one validator’s contribution to the consensus random seed stored in the Random ledger object. It is never submitted by users.

Each proposing validator on the UNLReport puts exactly one Entropy pseudo-transaction into its own initial consensus position when it closes a ledger. The transaction never enters the open ledger, so its contents only become public after that validator’s transaction set is locked. This commit-reveal scheme means no single validator (or Hook) can predict or steer the result.

Example

An Entropy pseudo-transaction from the Release Candidate devnet:

{
  "TransactionType": "Entropy",
  "Account": "",
  "Fee": "0",
  "Sequence": 0,
  "SigningPubKey": "",
  "LedgerSequence": 9224,
  "PublicKey": "EDB92F505485DE1B273FB67D6FB1F101AA01BFA0C5F65D67496FE85E912ECB4487",
  "NextRandomDigest": "754C777405ACA07DAFD7D6EA855202E543D4F10F71DCBDF6AA04CF4BB4253094",
  "RandomData": "5565EE66052941AD7048A8FF8B81ACFA9D8ACC28CC9F3AF3266C72DA9D73B4A9",
  "hash": "E4348BFE35489BAE5859C53ED33852C096A8AA85257AAD255CAC1BB1D4779339"
}

Fields

Field	JSON Type	Internal Type	Description
LedgerSequence	Number	UInt32	The ledger index where this pseudo-transaction appears.
PublicKey	String	Blob	The master public key of the validator contributing the entropy (as listed in the UNLReport).
NextRandomDigest	String	Hash256	The validator’s commitment to a new secret, which it will reveal in a later ledger.
RandomData	String	Hash256	(Optional) The reveal of the secret the validator committed to previously. Omitted if the ledger no longer holds that validator’s previous commitment.

Common Fields

Entropy uses the following values for the common fields:

Field	Value
Account	"" (empty, ACCOUNT_ZERO)
Fee	0
Sequence	0
SigningPubKey	"" (empty string)
TxnSignature	Omitted.

Processing

When the ledger is built, all Entropy pseudo-transactions are applied before any other transaction:

• Its metadata modifies only the Random object (for example, incrementing EntropyCount). RandomData and RandomDigests never appear in that metadata.
• A RandomData reveal that matches the validator’s stored commitment is mixed into the ledger’s seed and counted in the EntropyCount field of the Random object.
• A missing, lost or mismatched reveal just re-registers the new commitment (NextRandomDigest). This has the same effect as the validator withholding.
• A commitment that is not refreshed within 8 ledgers is dropped.

Only validators on the UNLReport may contribute, when a UNLReport exists. Validators need no configuration: contribution is automatic once the RNG amendment is enabled.

Hooks cannot inspect Entropy transactions: slot_set refuses them. The transaction type code is 89 (ttENTROPY in the Hook headers).

Related Documentation

• Random ledger object
• RNG amendment