Sign privacy marker transactions
You can sign privacy marker transactions (PMTs) with either a random key or a specified key. To sign privacy marker transactions with a specified private key, use --privacy-marker-transaction-signing-key-file when starting Besu.
The private key file can be the same file used by --node-private-key-file, or a different key file to identify who signed the privacy marker transaction.
In networks where you pay gas, you must specify a key and the associated account must contain adequate funds.
In free gas networks, to provide further anonymity by signing each privacy marker transaction with a different random key, exclude the --privacy-marker-transaction-signing-key-file command line option when starting Besu.
You can't use account permissioning with random key signing.
If using account permissioning and privacy, a signing key must be specified using the --privacy-marker-transaction-signing-key-file command line option and the corresponding public key included in the accounts allowlist.
Besu signs privacy marker transactions during the private transaction process.