pub fn recipient_pseudonym(
per_recipient_secret: &[u8; 32],
scope: RekeyScope,
epoch: Epoch,
) -> PseudonymExpand description
Per-recipient rekey-blob tag. IKM is the pairwise sender↔recipient
ECDH secret (not the channel key), so only that pair can locate the blob and a
removed member cannot derive tags for pairs they are not in.