Fraunhofer SIT Microsoft Microsoft Microsoft A transparent and authentic ledger service in support of a supply chain's integrity, transparency, and trust requires all peers that contribute to the ledgers operations to be trustworthy and authentic. In this document, a countersigning variant is specified that enables trust assertions on merkle-tree based operations for global supply chain ledgers. A generic procedure how to produce payloads for signing and validation is defined and leverages solutions and principles from the Concise Signing and Encryption (COSE) space.